SILABS SI5338

Si5338
I 2 C - P R O G R A M M A B LE A N Y - F R E Q U E N C Y, A N Y -O UTPU T Q U A D C L OC K G E N E R A T O R
Features
Applications
CLK0B
VDDO0
SDA
22
21
20
19
18 CLK1A
IN2 2
17 CLK1B
IN3 3
16 VDDO1
GND
GND
Pad
IN4 4
15 VDDO2
IN5 5




Any-frequency clock conversion
MSAN/DSLAM/PON
Fibre Channel, SAN
Telecom line cards
14 CLK2A
IN6 6
13 CLK2B
7
8
9
10
11
12
SCL
Ethernet switch/router
PCI Express 2.0/3.0
Broadcast video/audio timing
Processor and FPGA clocking
23
IN1 1
VDDO3




24
Top View
CLK3A

I2C/SMBus compatible interface
Easy to use programming software
Small size: 4 x 4 mm, 24-QFN
Low power: 45 mA core supply typ
Wide temperature range: –40 to
+85 °C
RSVD_GND

Pin Assignments
CLK0A

Ordering Information:
See page 168.
CLK3B

VDD

Single supply core with excellent
PSRR: 1.8, 2.5, 3.3 V
Independent frequency increment/
decrement feature enables
glitchless frequency adjustments in
1 ppm steps
Independent phase adjustment on
each of the output drivers with an
accuracy of <20 ps steps
Highly configurable spread
spectrum (SSC) on any output:
Any frequency from 5 to 350 MHz
Any spread from 0.5 to 5.0%
Any modulation rate from 33 to
63 kHz
External feedback mode allows
zero-delay mode
Loss of lock and loss of signal
alarms
VDD

Low power MultiSynth™ technology 
enables independent, any-frequency
synthesis on four differential output

drivers
Highly-configurable output drivers with
up to four differential outputs, eight
single-ended clock outputs, or a

combination of both
Low phase jitter of 0.7 ps RMS typ
High precision synthesis allows true 
zero ppm frequency accuracy on all
outputs
Flexible input reference:
External crystal: 8 to 30 MHz
CMOS input: 5 to 200 MHz
SSTL/HSTL input: 5 to 350 MHz

Differential input: 5 to 710 MHz

Independently configurable outputs
support any frequency or format:
LVPECL/LVDS: 0.16 to 710 MHz

HCSL: 0.16 to 250 MHz

CMOS: 0.16 to 200 MHz

SSTL/HSTL: 0.16 to 350 MHz

Independent output voltage per driver: 
1.5, 1.8, 2.5, or 3.3 V
INTR

Description
The Si5338 is a high-performance, low-jitter clock generator capable of
synthesizing any frequency on each of the device's four output drivers. This timing
IC is capable of replacing up to four different frequency crystal oscillators or
operating as a frequency translator. Using its patented MultiSynth™ technology,
the Si5338 allows generation of four independent clocks with 0 ppm precision.
Each output clock is independently configurable to support various signal formats
and supply voltages. The Si5338 provides low-jitter frequency synthesis in a
space-saving 4 x 4 mm QFN package. The device is programmable via an I2C/
SMBus-compatible serial interface and supports operation from a 1.8, 2.5, or
3.3 V core supply. I2C device programming is made easy with the ClockBuilder™
Desktop software available at www.silabs.com/ClockBuilder.
Rev. 0.6 9/10
Copyright © 2010 by Silicon Laboratories
Si5338
Si5338
Functional Block Diagram
VDD
Osc
Synthesis
Stage 1
(PLL)
noclk
P1DIV_IN
IN1
IN2
Synthesis
Stage 2
MultiSynth
÷M0
ref
÷P1
Output
Stage
VDDO0
÷R0
Phase
Frequency
Detector
P2DIV_IN
IN4
IN5
IN6
Loop
Filter
÷R1
noclk
OEB/PINC/FINC
Control
CLK1A
CLK1B
VDDO2
÷P2
NVM
(OTP)
MultiSynth
÷M2
÷R2
MultiSynth
÷M3
÷R3
RAM
Rev. 0.6
CLK2A
CLK2B
MultiSynth
÷N
I2C_LSB/PDEC/FDEC
2
VDDO1
MultiSynth
÷M1
fb
Control & Memory
SCL
SDA
INTR
VCO
CLK0A
CLK0B
IN3
VDDO3
CLK3A
CLK3B
Si5338
TABLE O F C ONTENTS
Section
Page
1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2. Typical Application Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.2. Input Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.3. Synthesis Stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.4. Output Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
3.5. Configuring the Si5338 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.6. Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.7. Output Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.8. Reset Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.9. Features of the Si5338 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4. Applications of the Si5338 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
4.1. Free-Running Clock Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.2. Synchronous Frequency Translation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.3. Configurable Buffer and Level Translator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5. I2C Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6. Si5338 Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
6.1. Register Write-Allowed Mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
6.2. Register Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
6.3. Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6.4. Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
7. Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
8. Device Pinout by Part Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .164
9. Package Outline: 24-Lead QFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
10. Recommended PCB Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
11. Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .170
Rev. 0.6
3
Si5338
1. Electrical Specifications
Table 1. Recommended Operating Conditions
(VDD = 1.8 V –5% to +10%, 2.5 V ±10%, or 3.3 V ±10%, TA = –40 to 85 °C)
Parameter
Ambient Temperature
Core Supply Voltage
Output Buffer Supply
Voltage
Symbol
Test Condition
TA
VDD
Min
Typ
Max
Unit
–40
25
85
°C
2.97
3.3
3.63
V
2.25
2.5
2.75
V
1.71
1.8
1.98
V
1.4
—
3.63
V
VDDOn
Note: All minimum and maximum specifications are guaranteed and apply across the recommended operating conditions.
Typical values apply at nominal supply voltages and an operating temperature of 25 °C unless otherwise noted.
Table 2. Absolute Maximum Ratings
Parameter
Symbol
Test Condition
Value
Unit
DC Supply Voltage
VDD
–0.5 to 3.8
V
Storage Temperature Range
TSTG
–55 to 150
°C
ESD Tolerance
HBM
(100 pF, 1.5 k)
2.5
kV
ESD Tolerance
CDM
550
V
ESD Tolerance
MM
175
V
Latch-up Tolerance
Junction Temperature
JESD78 Compliant
150
TJ
°C
Note: Permanent device damage may occur if the Absolute Maximum Ratings are exceeded. Functional operation should be
restricted to the conditions as specified in the operational sections of this data sheet. Exposure to absolute maximum
rating conditions for extended periods may affect device reliability.
4
Rev. 0.6
Si5338
Table 3. DC Characteristics
(VDD = 1.8 V –5% to +10%, 2.5 V ±10%, or 3.3 V ±10%, TA = –40 to 85 °C)
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
IDD
100 MHz on all outputs,
25 MHz refclk
—
45
60
mA
LVPECL, 710 MHz
—
—
30
mA
LVDS, 710 MHz
—
—
8
mA
HCSL, 250 MHz
2 pF load
—
—
20
mA
SSTL, 350 MHz
—
—
19
mA
CMOS, 50 MHz
15 pF load
—
—
28
mA
CMOS, 200 MHz
2 pF load, 3.3 V VDD0
—
—
20
mA
CMOS, 200 MHz
2 pF load, 2.5 V
—
13
17
mA
CMOS, 200 MHz
2 pF load, 1.8 V
—
11
15
mA
HSTL, 350 MHz
—
—
19
mA
Core Supply Current
Output Buffer Supply Current
IDDOx
Table 4. Thermal Characteristics
Parameter
Symbol
Test Condition
Value
Unit
Thermal Resistance
Junction to Ambient
JA
Still Air
37
°C/W
Thermal Resistance
Junction to Case
JC
Still Air
25
°C/W
Rev. 0.6
5
Si5338
Table 5. Performance Characteristics
(VDD = 1.8 V –5% to +10%, 2.5 V ±10%, or 3.3 V ±10%, TA = –40 to 85 °C)
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
PLL Acquisition Time
tACQ
—
—
25
ms
PLL Lock Range
fLOCK
5000
—
—
ppm
PLL Loop Bandwidth
fBW
—
1.6
—
MHz
MultiSynth Frequency
Synthesis Resolution
fRES
0
0
1
ppb
CLKIN Loss of Signal Detect
Time
tLOS
—
2.6
5
µs
CLKIN Loss of Signal Release
Time
tLOSRLS
0.01
0.2
1
µs
PLL Loss of Lock Detect Time
tLOL
—
5
10
ms
POR to Output Clock Valid
(Pre-programmed Devices)
tRDY
—
—
2
ms
Input-to-Output Propagation
Delay
tPROP
Buffer Mode
(PLL Bypass)
—
2.5
—
ns
tDSKEW
Rn divider = 11
—
—
100
ps
—
—
15
ms
–45
—
+45
ns
Output-Output Skew
Output frequency < Fvco/8
POR to I2C Ready
Programmable Initial
Phase Offset
POFFSET
Phase Increment/Decrement
Accuracy
PSTEP
—
—
20
ps
Phase Increment/Decrement
Range
PRANGE
–45
—
+45
ns
Frequency range for phase
increment/decrement
fPRANGE
—
—
3502
MHz
Phase Increment/Decrement
Update Time
PUPDATE
667
—
—
ns
Pin control2,3
MultiSynth output >18 MHz
Notes:
1. Outputs at integer-related frequencies and using the same driver format. See "3.9.3. Initial Phase Offset" on page 24.
2. The maximum step size is only limited by the register lengths; however, the MultiSynth output frequency must be kept
between 5 MHz and Fvco/8.
3. Update rate via I2C is also limited by the time it takes to perform a write operation.
4. Default value is 0.5% down spread.
5. Default value is ~31.5 kHz.
6
Rev. 0.6
Si5338
Table 5. Performance Characteristics (Continued)
(VDD = 1.8 V –5% to +10%, 2.5 V ±10%, or 3.3 V ±10%, TA = –40 to 85 °C)
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
Phase Increment/Decrement
Update Time
PUPDATE
Pin control2,3
MultiSynth output <18 MHz
Number of periods of
MultiSynth output frequency
—
12
—
Periods
Frequency Increment/
Decrement Step Size
fSTEP
R divider not used
1
—
See
Note 2
ppm
Frequency Increment/
Decrement Range
fRANGE
R divider not used
—
—
3502
MHz
Frequency Increment/
Decrement Update Time
fUPDATE
Pin control2,3
MultiSynth output >18 MHz
667
—
—
ns
Frequency Increment/
Decrement Update Time
fUPDATE
Pin control2,3
MultiSynth output <18 MHz
Number of periods of
MultiSynth output frequency
—
12
—
Periods
Spread Spectrum PP
Frequency Deviation
SSDEV
MultiSynth Output < ~Fvco/8
0.1
—
5.04
%
Spread Spectrum Modulation
Rate
SSDEV
MultiSynth Output < ~Fvco/8
30
—
635
kHz
Notes:
1. Outputs at integer-related frequencies and using the same driver format. See "3.9.3. Initial Phase Offset" on page 24.
2. The maximum step size is only limited by the register lengths; however, the MultiSynth output frequency must be kept
between 5 MHz and Fvco/8.
3. Update rate via I2C is also limited by the time it takes to perform a write operation.
4. Default value is 0.5% down spread.
5. Default value is ~31.5 kHz.
Table 6. Input and Output Clock Characteristics
(VDD = 1.8 V –5% to +10%, 2.5 V ±10%, or 3.3 V ±10%, TA = –40 to 85 °C)
Parameter
Symbol
Test Condition
Min
Typ
Max
Units
5
—
710
MHz
Input Clock (AC Coupled Differential Input Clocks on Pins IN1/2, IN5/6)
fIN
Frequency
Differential Voltage
Swing
VPP
710 MHz input
0.4
—
2.4
VPP
Rise/Fall Time
tR/tF
20%–80%
—
—
1.0
ns
DC
< 1 ns tr/tf
40
—
60
%
1
Duty Cycle
Notes:
1. For best jitter performance, keep the input slew rate on pins 1,2,5,6 faster than 0.3 V/ns
2. Not in PLL bypass mode.
3. For best jitter performance, keep the input single ended slew rate on pins 3 or 4 faster than 1 V/ns
4. Only two unique frequencies above 350 MHz can be simultaneously output, Fvco/4 and Fvco/6.
5. Includes effect of internal series 22  resistor.
Rev. 0.6
7
Si5338
Table 6. Input and Output Clock Characteristics (Continued)
(VDD = 1.8 V –5% to +10%, 2.5 V ±10%, or 3.3 V ±10%, TA = –40 to 85 °C)
Parameter
Symbol
Test Condition
Min
Typ
Max
Units
Input Impedance
RIN
10
—
—
k
Input Capacitance
CIN
—
3.5
—
pF
5
—
200
MHz
–0.1
—
3.63
V
200 MHz
0.8
—
VDD+10%
Vpp
Input Clock (DC-Coupled Single-Ended Input Clock on Pins IN3/4)
Frequency
fIN
Input Voltage
VI
Input Voltage Swing
CMOS
Rise/Fall Time
tR/tF
20%–80%
—
—
2
ns
Duty Cycle2,3
DC
< 4 ns tr/tf
40
—
60
%
Input Capacitance
CIN
—
2.0
—
pF
0.16
—
350
MHz
367
—
473.33
MHz
550
—
710
MHz
HCSL
0.16
—
250
MHz
VOC
common mode
—
VDDO–1.45 V
—
V
VSEPP
peak-to-peak singleended swing
0.55
0.8
0.96
VPP
VOC
common mode
1.125
1.2
1.275
V
VSEPP
peak-to-peak singleended swing
0.25
0.35
0.45
VPP
VOC
common mode
0.8
0.875
0.95
V
VSEPP
peak-to-peak singleended swing
0.25
0.35
0.45
VPP
VOC
common mode
0.35
0.375
0.400
V
VSEPP
peak-to-peak singleended swing
0.575
0.725
0.85
VPP
Rise/Fall Time
tR/tF
20%–80%
—
—
450
ps
Duty Cycle2
DC
45
—
55
%
Output Clocks (Differential)
Frequency4
LVPECL Output Voltage
LVDS Output Voltage
(2.5/3.3 V)
LVDS Output Voltage
(1.8 V)
HCSL Output Voltage
LVPECL, LVDS
fOUT
Notes:
1. For best jitter performance, keep the input slew rate on pins 1,2,5,6 faster than 0.3 V/ns
2. Not in PLL bypass mode.
3. For best jitter performance, keep the input single ended slew rate on pins 3 or 4 faster than 1 V/ns
4. Only two unique frequencies above 350 MHz can be simultaneously output, Fvco/4 and Fvco/6.
5. Includes effect of internal series 22  resistor.
8
Rev. 0.6
Si5338
Table 6. Input and Output Clock Characteristics (Continued)
(VDD = 1.8 V –5% to +10%, 2.5 V ±10%, or 3.3 V ±10%, TA = –40 to 85 °C)
Parameter
Symbol
Test Condition
Min
Typ
Max
Units
CMOS
0.16
—
200
MHz
SSTL, HSTL
0.16
—
350
MHz
Output Clocks (Single-Ended)
Frequency
fOUT
CMOS 20%–80%
Rise/Fall Time
tR/tF
2 pF load
—
0.45
0.85
ns
CMOS 20%–80%
Rise/Fall Time
tR/tF
15 pF load
—
—
1.7
ns
CMOS Output Resistance
—
50
—

SSTL Output
Resistance
—
50
—

HSTL Output
Resistance
—
50
—

VDDO – 0.3
—
CMOS Output Voltage5
VOH
4 mA load
VOL
4 mA load
VOH
SSTL-3 VDDOx = 2.97
to 3.63 V
—
0.3
V
0.45xVDDO+0.41
—
—
V
—
—
0.45xVDDO–0.41
V
SSTL-2 VDDOx = 2.25
to 2.75 V
0.5xVDDO+0.41
—
—
V
—
—
0.5xVDDO–0.41
V
SSTL-18 VDDOx = 1.71
to 1.98 V
0.5xVDDO+0.34
—
—
—
0.5xVDDO–0.34
V
0.5xVDDO+0.3
—
—
V
VOL
—
—
0.5xVDDO –0.3
V
DC
45
—
55
%
VOL
SSTL Output Voltage
VOH
VOL
VOH
VOL
HSTL Output Voltage
Duty Cycle2
V
VOH
V
VDDO = 1.4 to 1.6 V
Notes:
1. For best jitter performance, keep the input slew rate on pins 1,2,5,6 faster than 0.3 V/ns
2. Not in PLL bypass mode.
3. For best jitter performance, keep the input single ended slew rate on pins 3 or 4 faster than 1 V/ns
4. Only two unique frequencies above 350 MHz can be simultaneously output, Fvco/4 and Fvco/6.
5. Includes effect of internal series 22  resistor.
Rev. 0.6
9
Si5338
Table 7. Control Pins
(VDD = 1.8 V –5% to +10%, 2.5 V ±10%, or 3.3 V ±10%, TA = –40 to 85 °C)
Parameter
Symbol
Condition
Min
Typ
Max
Unit
Input Control Pins (IN3, IN4)
Input Voltage Low
VIL
–0.1
—
0.3 x
VDD
V
Input Voltage High
VIH
0.7 x
VDD
—
3.63
V
Input Capacitance
CIN
—
—
4
pF
Input Resistance
RIN
—
20
—
k
Output Control Pins (INTR)
Output Voltage Low
VOL
ISINK = 3 mA
0
—
0.4
V
Rise/Fall Time 20–80%
tR/tF
CL < 10 pf, pull up 1 k
—
—
10
ns
10
Rev. 0.6
Si5338
Table 8. Crystal Specifications for 8 to 11 MHz
Parameter
Symbol
Min
Typ
Max
Unit
fXTAL
8
—
11
MHz
Load Capacitance (on-chip differential)
cL
11
12
13
pF
Crystal Output Capacitance
cO
—
—
6
pF
rESR
—
—
300

dL
100
—
—
µW
Symbol
Min
Typ
Max
Unit
fXTAL
11
—
19
MHz
Load Capacitance (on-chip differential)
cL
11
12
13
pF
Crystal Output Capacitance
cO
—
—
5
pF
rESR
—
—
200

dL
100
—
—
µW
Symbol
Min
Typ
Max
Unit
fXTAL
19
26
MHz
Load Capacitance (on-chip differential)
cL
11
13
pF
Crystal Output Capacitance
cO
5
pF
rESR
100

Crystal Frequency
Equivalent Series Resistance
Crystal Max Drive Level
Table 9. Crystal Specifications for 11 to 19 MHz
Parameter
Crystal Frequency
Equivalent Series Resistance
Crystal Max Drive Level
Table 10. Crystal Specifications for 19 to 26 MHz
Parameter
Crystal Frequency
Equivalent Series Resistance
dL
100
Symbol
Min
fXTAL
26
Load Capacitance (on-chip differential)
cL
11
Crystal Output Capacitance
Crystal Max Drive Level
12
µW
Table 11. Crystal Specifications for 26 to 30 MHz
Parameter
Crystal Frequency
Equivalent Series Resistance
Crystal Max Drive Level
Max
Unit
30
MHz
13
pF
cO
5
pF
rESR
75

dL
Rev. 0.6
100
Typ
12
µW
11
Si5338
Table 12. Jitter Specifications1,2
(VDD = 1.8 V –5% to +10%, 2.5 V ±10%, or 3.3 V ±10%, TA = –40 to 85 °C)
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
GbE Random Jitter
(12 kHz–20 MHz)3
JGBE
CLKIN = 25 MHz
All CLKn at 125 MHz4
—
0.7
1
ps RMS
GbE Random Jitter
(1.875–20 MHz)
RJGBE
CLKIN = 25 MHz
All CLKn at 125 MHz4
—
0.38
0.79
ps RMS
OC-12 Random Jitter
(12 kHz–5 MHz)
JOC12
CLKIN = 19.44 MHz
All CLKn at
155.52 MHz4
—
0.7
1
ps RMS
JPCIERJ1
CLKIN = 25 MHz
All CLKn at 100 MHz
Spread Spectrum not
enabled4
—
0.6
1
ps RMS
JPCIERJ2
CLKIN = 25 MHz
All CLKn at 100 MHz
Spread Spectrum not
enabled4
—
0.7
1
ps RMS
PCI Express 3.0
Period Jitter
CLKIN = 25 MHz
All CLKn at 100 MHz
Spread Spectrum not
enabled4
—
8
15
ps pk-pk
PCI Express 3.0
Cycle-Cycle Jitter
CLKIN = 25 MHz
All CLKn at 100 MHz
Spread Spectrum not
enabled4
—
13
30
ps pk-pk
JPER
N = 10,000 cycles5
—
10
30
ps pk-pk
Cycle-Cycle Jitter
JCC
N = 10,000 cycles
Output MultiSynth
operated in integer or
fractional mode5
—
9
29
ps pk6
Random Jitter
(12 kHz–20 MHz)
RJ
Output and feedback
MultiSynth in integer or
fractional mode5
—
0.7
1.5
ps RMS
PCI Express 3.0
Random Jitter
(1.5 MHz—50 MHz)3
PCI Express 3.0
Random Jitter
(12 kHz—20 MHz)3
Period Jitter
Notes:
1. All jitter measurements apply for LVDS/HCSL/LVPECL output format with a low noise differential input clock and are
made with an Agilent 90804 oscilloscope. All RJ measurements use RJ/DJ separation.
2. For best jitter performance, keep the single ended clock input slew rates at Pins 3 and 4 more than 1.0 V/ns and the
differential clock input slew rates more than 0.3 V/ns.
3. DJ for PCI and GBE is < 5 ps pp
4. Output MultiSynth in Integer mode.
5. Input frequency to the Phase Detector between 25 and 40 MHz and any output frequency > 5 MHz.
6. Measured in accordance with JEDEC standard 65.
7. Rj is multiplied by 14; estimate the pp jitter from Rj over 212 rising edges.
12
Rev. 0.6
Si5338
Table 12. Jitter Specifications1,2 (Continued)
(VDD = 1.8 V –5% to +10%, 2.5 V ±10%, or 3.3 V ±10%, TA = –40 to 85 °C)
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
—
3
15
ps pk-pk
—
2
10
ps pk-pk
Output MultiSynth
operated in fractional
mode5
—
13
36
ps pk-pk
Output MultiSynth
operated in integer
mode5
—
12
20
ps pk-pk
Output MultiSynth
operated in fractional
5
Deterministic Jitter
mode
DJ
Output MultiSynth
operated in integer
mode5
Total Jitter
(12 kHz–20 MHz)
TJ = DJ+14xRJ
(See Note 7)
Notes:
1. All jitter measurements apply for LVDS/HCSL/LVPECL output format with a low noise differential input clock and are
made with an Agilent 90804 oscilloscope. All RJ measurements use RJ/DJ separation.
2. For best jitter performance, keep the single ended clock input slew rates at Pins 3 and 4 more than 1.0 V/ns and the
differential clock input slew rates more than 0.3 V/ns.
3. DJ for PCI and GBE is < 5 ps pp
4. Output MultiSynth in Integer mode.
5. Input frequency to the Phase Detector between 25 and 40 MHz and any output frequency > 5 MHz.
6. Measured in accordance with JEDEC standard 65.
7. Rj is multiplied by 14; estimate the pp jitter from Rj over 212 rising edges.
Table 13. Typical Phase Noise Performance
Offset Frequency
25MHz XTAL
to 156.25 MHz
27 MHz Ref In
to 148.3517 MHz
19.44 MHz Ref In
to 155.52 MHz
100 Hz
–90
–87
–110
1 kHz
–120
–117
–116
10 kHz
–126
–123
–123
100 kHz
–132
–130
–128
1 MHz
–132
–132
–128
10 MHz
–145
–145
–145
Units
dBc/Hz
Rev. 0.6
13
Si5338
Table 14. I2C Specifications (SCL,SDA)1
Parameter
Symbol
Test Condition
Standard Mode
Fast Mode
Unit
Min
Max
Min
Max
LOW Level Input
Voltage
VILI2C
–0.5
0.3 x VDDI2C
–0.5
0.3 x VDDI2C2
V
HIGH Level Input
Voltage
VIHI2C
0.7 x VDDI2C
3.63
0.7 x VDDI2C2
3.63
V
Hysteresis of
Schmitt Trigger
Inputs
VHYS
N/A
N/A
0.1
—
V
VDDI2C2 = 2.5/3.3 V
0
0.4
0
0.4
V
VDDI2C2 = 1.8 V
N/A
N/A
0
0.2 x VDDI2C
V
–10
10
–10
10
µA
LOW Level Output Voltage (open
drain or open collector) at 3 mA
Sink Current
VOLI2C2
Input Current
II2C
Capacitance for
each I/O Pin
CI2C
VIN = –0.1 to VDDI2C
—
4
—
4
pF
I2C Bus Timeout
—
Timeout Enabled
25
35
25
35
ms
Notes:
1. Refer to NXP’s UM10204 I2C-bus specification and user manual, Revision 03, for further details:
www.nxp.com/acrobat_download/usermanuals/UM10204_3.pdf.
2. Only I2C pullup voltages (VDDI2C) of 1.71 to 3.63 V are supported. Must write register 27[7] = 1 if the I2C bus voltage
is less than 2.5 V to maintain compatibility with the I2C bus standard.
14
Rev. 0.6
Si5338
2. Typical Application Circuits
+3.3 V
SD/HD/3G-SDI
Video/Audio
Format Converter
0.1 uF Power Supply
Decoupling Capacitors
(1 per VDD or VDDOx pin)
2
3
27 MHz
74.25 MHz
74.25/1.001 MHz
148.5 MHz
148.5/1.001 MHz
Single-ended or
Differential Inputs
for Synchronous
Applications
1
27 MHz
XTAL
5
IN3
CLK0A
CLK0B
IN5
Si5338C
CLK1A
IN6
+3.3 V
CLK2A
CLK2B
1k
I C Bus
12
4
2
I C Address = 111 0000 or 111 0001
SDI
Serializer
INTR
CLK3A
SDA
CLK3B
21
x
100
74.25 MHz, 74.25/1.001 MHz
148.5 MHz, 148.5/1.001 MHz
18
17
14
13
Audio Out
x
x
Audio
Processor
9
IN3
24.576 MHz / 6.144 MHz
10
SCL
I2C_LSB
100 MHz
22
x
GND
8
19
2
GND
1k
Video
Processor
IN2
CLK1B
1k
SDI
Deserializer
IN1
100
6
SD/HD/3G
SDI OUT
SD/HD/3G
SDI IN
VDDOD
VDDOB
VDD
15 11
VDDOC
Optional XTAL for
Free-run Applications
20 16
VDDOA
VDD
7 24
PAD
PAD
23
23
Storage Area
Network
+3.3 V
disk
2
3
x
5
6
IN2
IN3
CLK0A
CLK0B
IN5
IN6
Si5338C
CLK1A
CLK2A
CLK2B
1k
I2C Address = 111 0000 or 111 0001
19
12
4
SAS2
4/8 Port
Controller
PCIe
Switch
Ethernet
Fiber
Channel
INTR
CLK3A
SDA
CLK3B
SCL
I2C_LSB
23
23
37.5/75/120/150 MHz
22
21
100 MHz
18
17
x
66 MHz
14
13
x
106.25 MHz
10
9
Network
Processor
x
GND
I2C Bus
GND
8
SAS2
4/8 Port
Controller
disk
+3.3V
1k
disk
IN1
CLK1B
1k
disk
VDDOD
VDDOC
VDDOB
15 11
VDD
20 16
VDDOA
1
25 MHz
XTAL
7 24
VDD
0.1 uF Power Supply
Decoupling Capacitors
(1 per VDD or VDDOx pin)
PAD
PAD
Rev. 0.6
15
Si5338
3. Functional Description
VDD
Synthesis
Stage 1
(PLL)
Input
Stage
Osc
Synthesis
Stage 2
CLKIN
IN1
IN2
Output
Stage
VDDO0
MultiSynth
÷M0
÷R0
MultiSynth
÷M1
÷R1
MultiSynth
÷M2
÷R2
CLK0A
CLK0B
ref
÷P1
IN3
Phase
Frequency
Detector
FDBK
IN4
IN5
IN6
Loop
Filter
VCO
VDDO1
CLK1A
CLK1B
fb
÷P2
VDDO2
OEB/PINC/FINC
Control
VDDO3
MultiSynth
÷M3
I2C_LSB/PDEC/FDEC
SCL
SDA
INTR
CLK2B
MultiSynth
÷N
Control & Memory
NVM
RAM
(OTP)
CLK2A
÷R3
CLK3A
CLK3B
Figure 1. Si5338 Block Diagram
3.1. Overview
The Si5338 is a high-performance, low-jitter clock
generator capable of synthesizing four independent
user-programmable clock frequencies up to 350 MHz
and select frequencies up to 710 MHz. The device
supports free-run operation using an external crystal, or
it can lock to an external clock for generating
synchronous clocks. The output drivers support four
differential clocks or eight single-ended clocks or a
combination of both. The output drivers are configurable
to support common signal formats, such as LVPECL,
LVDS, HCSL, CMOS, HSTL, and SSTL. Separate
output supply pins allow supply voltages of 3.3, 2.5, 1.8,
and 1.5 V to support the multi-format output driver. The
core voltage supply accepts 3.3, 2.5, or 1.8 V and is
independent from the output supplies.
Using its two-stage synthesis architecture and patented
high-resolution MultiSynth technology, the Si5338 can
generate four independent frequencies from a single
input frequency. In addition to clock generation, the
inputs can bypass the synthesis stage enabling the
Si5338 to be used as a high-performance clock buffer or
a combination of a buffer and generator.
For applications that need fine frequency adjustments,
such as clock margining, each of the synthesized
frequencies can be incremented or decremented in
user-defined steps as low as 1 ppm per step.
Output-to-output phase delays are also adjustable in
user-defined steps with an error of <20 ps to
compensate for PCB trace delays or for fine tuning of
setup and hold margins.
16
A zero-delay mode is also available to help minimize
input-to-output delay. Spread spectrum is available on
each of the clock outputs for EMI-sensitive applications,
such as PCI Express.
Configuration and control of the Si5338 is mainly
handled through the I2C/SMBus interface. Some
features, such as output enable and frequency or phase
adjustments, can optionally be pin controlled. The
device has a maskable interrupt pin that can be
monitored for loss of lock or loss of input signal
conditions.
The device also provides the option of storing a userdefinable clock configuration in its non-volatile memory
(NVM), which becomes the default clock configuration
at power-up.
3.1.1. ClockBuilder™ Desktop Software
To simplify device configuration, Silicon Labs provides
ClockBuilder Desktop software. To ease these steps,
Silicon Labs has released ClockBuilder Desktop. The
software serves two purposes: configure the Si5338
with optimal divider ratios based on the desired
frequencies, and to control the EVB, if connected to the
host PC. The optimal configuration can be saved from
the software in text files that can be used in any system,
which configures the device over I2C.
ClockBuilder Desktop can be downloaded from
www.silabs.com/ClockBuilder and runs on Windows XP,
Windows Vista, and Windows 7.
Rev. 0.6
Si5338
3.2. Input Stage
The input stage supports four inputs. Two are used as
the clock inputs to the synthesis stage, and the other
two are used as feedback inputs for zero delay or
external feedback mode. In cases where external
feedback is not required, all four inputs are available to
the synthesis stage. The reference selector selects one
of the inputs as the reference to the synthesis stage.
The input configuration is selectable through the IC
interface. The input MUXes are set automatically in
ClockBuilder Desktop (see “3.1.1. ClockBuilder™
Desktop Software”). For information on setting the input
MUXs manually, see “AN411: Configuring the Si5338”.
Osc
To Synthesis Stage
noclk
P1DIV_IN
IN1
IN2
÷P1
IN3
P2DIV_IN
IN4
IN5
IN6
÷P2
IN3 and IN4 accept single-ended signals from 5 MHz to
200 MHz. The single-ended inputs are internally accoupled; so, they can accept a wide variety of signals
without requiring a specific dc level. The input signal
only needs to meet a minimum voltage swing and must
not exceed a maximum VIH or a minimum VIL. Refer to
Table 6 for signal voltage limits. A typical single-ended
connection is shown in Figure 3. For additional
termination options, refer to “AN408: Termination
Options for Any-Frequency, Any-Output Clock
Generators and Clock Buffers—Si5338, Si5334,
Si5330”.
For free-run operation, the internal oscillator can
operate from a low-frequency fundamental mode crystal
(XTAL) with a resonant frequency between 8 and
30 MHz. A crystal can easily be connected to pins IN1
and IN2 without external components as shown in
Figure 4. See Tables 8–11 for crystal specifications that
are guaranteed to work with the Si5338.
IN1
Osc
XTAL
noclk
To synthesis stage
or output selectors
IN2
Figure 2. Input Stage
Figure 4. Connecting an XTAL to the Si5338
IN1/IN2 and IN5/IN6 are differential inputs capable of
accepting clock rates from 5 to 710 MHz. The
differential inputs are capable of interfacing to multiple
signals, such as LVPECL, LVDS, HSCL, HCSL, and
CML. Differential signals must be ac-coupled as shown
in Figure 3. A termination resistor of 100  placed close
to the input pins is also required. Refer to Table 6 for
signal voltage limits.
0.1 uF
50
IN1 / IN5
IN2 / IN6
100
3.2.1. Loss-of-Signal (LOS) Alarm Detectors
There are two LOS detectors: LOS_CLKIN and
LOS_FDBK. These detectors are tied to the outputs of
the P1 and P2 frequency dividers, which are always
enabled. See "3.6. Status Indicators" on page 22 for
details on the alarm indicators. These alarms are used
during programming to ensure that a valid input clock is
detected. The input MUXs are set automatically in
ClockBuilder Desktop (see AN411 to set manually).
3.3. Synthesis Stages
50
0.1 uF
Rs
50
Refer to “AN360: Crystal Selection Guide for Si533x/5x
Devices” for information on the crystal selection.
IN3 / IN4
Figure 3. Interfacing Differential and SingleEnded Signals to the Si5338
Next-generation timing applications require a wide
range of frequencies that are often non-integer related.
Traditional clock architectures address this by using
multiple single PLL ICs, often at the expense of BOM
complexity and power. The Si5338 uses patented
MultiSynth technology to dramatically simplify timing
architectures by integrating the frequency synthesis
capability of four Phase-Locked Loops (PLLs) in a
single device, greatly reducing size and power
requirements versus traditional solutions.
Rev. 0.6
17
Si5338
Synthesis of the output clocks is performed in two
stages, as shown in Figure 5. The first stage consists of
a high-frequency analog phase-locked loop (PLL) that
multiplies the input stage to a frequency within the
range of 2.2 to 2.84 GHz. Multiplication of the input
frequency is accomplished using a proprietary and
highly precise MultiSynth feedback divider (N), which
allows the PLL to generate any frequency within its
VCO range with much less jitter than typical fractional N
PLL.
Synthesis
Stage 2
MultiSynth
÷M0
2.2-2.84 GHz
ref
Phase
Frequency
Detector
Loop
Filter
VCO
MultiSynth
÷M1
fb
MultiSynth
÷M2
MultiSynth
÷N
MultiSynth
÷M3
Figure 5. Synthesis Stages
To Output Stage
From Input Stage
Synthesis
Stage 1
(APLL)
The second stage of synthesis consists of the output
MultiSynth dividers (Mx). Based on a fractional N
divider, the MultiSynth divider shown in Figure 6
switches seamlessly between the two closest integer
divider values to produce the exact output clock
frequency with 0 ppm error.
To eliminate phase error generated by this process, the
MultiSynth block calculates the relative phase difference
between the clock produced by the fractional-N divider
and the desired output clock and dynamically adjusts
the phase to match the ideal clock waveform. This novel
approach makes it possible to generate any output
clock frequency without sacrificing jitter performance.
This architecture allows the output of each MultiSynth to
produce any frequency from 5 to Fvco/8 MHz. To
support higher frequency operation, the MultiSynth
divider can be bypassed. In bypass mode, integer divide
ratios of 4 and 6 are supported. This allows for output
frequencies of Fvco/4 and Fvco/6 MHz, which translates
to 367–473.33 MHz and 550–710 MHz respectively.
Because each MultiSynth uses the same VCO output,
there are output frequency limitations when output
frequencies greater than Fvco/8 are desired.
For example, if 375 MHz is needed at the output of
MultiSynth0, the VCO frequency would need to be
2.25 GHz. Now, all the other MultiSynths can produce
any frequency from 5 MHz up to a maximum frequency
of 2250/8 = 281.25 MHz. MultiSynth1,2,3 could also
produce Fvco/4 = 562.5 MHz or Fvco/6 = 375 MHz. Only
two unique frequencies above Fvco/8 can be output:
Fvco/6 and Fvco/4.
MultiSynth
fVCO
Fractional-N
Divider
Phase
Adjust
Phase Error
Calculator
Divider Select
(DIV1, DIV2)
Figure 6. Silicon Labs’ MultiSynth Technology
18
Rev. 0.6
fOUT
Si5338
3.4. Output Stage
The output stage consists of output selectors, output
dividers, and programmable output drivers as shown in
Figure 7.
VDDO0
CLK0A
From Synthesis Stage
or Input Stage
CLK0B
VDDO1
÷R1
3.5. Configuring the Si5338
The Si5338 is a highly-flexible clock generator that is
entirely configurable through its I2C interface. The
device’s default configuration is stored in non-volatile
memory (NVM) as shown in Figure 8. The NVM is a
one-time programmable memory (OTP), which can
store a custom user configuration at power-up. This is a
useful feature for applications that need a clock present
at power-up (e.g., for providing a clock to a processor).
Output
Stage
÷R0
Each of the outputs can also be enabled or disabled
through the I2C port. A single pin to enable/disable all
outputs is available in the Si5338K/L/M.
CLK1A
CLK1B
Power-Up/POR
VDDO2
÷R2
CLK2A
NVM
(OTP)
CLK2B
RAM
VDDO3
÷R3
Default
Config
CLK3A
CLK3B
Figure 7. Output Stage
I2C
The output selectors select the clock source for the
output drivers. By default, each output driver is
connected to its own MultiSynth block (e.g. M0 to CLK0,
M1 to CLK1, etc), but other combinations are possible
by reconfiguring the device. The PLL can be bypassed
by connected the input stage signals (osc, ref, refdiv, fb,
or fbdiv) directly to the output divider. Bypassing an
input directly to an output will not allow phase alignment
of that output to other outputs. Each of the output
drivers can also connect to the first MultiSynth block
(M0) enabling a fan-out function. This allows the Si5338
to act as a clock generator, a fanout buffer, or a
combination of both in the same package.
The output dividers (R0, R1, R2, R3) allow another
stage of clock division.These dividers are configurable
as divide by 1 (default), 2, 4, 8, 16, or 32. When an Rn
does not equal 1, the phase alignment function for that
output will not work.
The output drivers are configurable to support common
signal formats, such as LVPECL, LVDS, HCSL, CMOS,
HSTL, and SSTL. Separate output supply pins (VDDOn)
are provided for each output buffer.
The voltage on these supply pins can be 3.3, 2.5, 1.8, or
1.5 V as needed for the possible output formats.
Additionally, the outputs can be configured to stop high,
low, or tri-state when the PLL has lost lock. If the Si5338
is used in a zero delay mode, the output that is fed back
must be set for always on, which will override any
output disable signal.
Figure 8. Si5338 Memory Configuration
During a power cycle or a power-on reset (POR), the
contents of the NVM are copied into random access
memory (RAM), which sets the device configuration that
will be used during operation. Any changes to the
device configuration after power-up are made by
reading and writing to registers in the RAM space
through the I2C interface. ClockBuilder Desktop (see
"3.1.1. ClockBuilder™ Desktop Software" on page 16)
can be used to easily configure register map files that
can be written into RAM (see “3.5.2. Creating a New
Configuration for RAM” for details). Alternatively, the
register map file can be created manually with the help
of the equations in AN411.
Two versions of the Si5338 are available. First,
standard, non-customized Si5338 devices are available
in which the RAM can be configured in-circuit via I2C
(example part number Si5338C-A-GM). Alternatively,
standard Si5338 devices can be field-programmed
using the Si5338-PROG-EVB field programmer.
Second, custom factory-programmed Si5338 devices
are available that include a user-specified startup
frequency configuration (example part number
Si5338C-Axxxxx-GM).
Rev. 0.6
19
Si5338
3.5.1. Ordering a Custom NVM Configuration
The Si5338 is orderable with a factory-programmed
custom NVM configuration. This is the simplest way of
using the Si5338 since it generates the desired output
frequencies at power-up or after a power-on reset
(POR). This default configuration can be reconfigured in
RAM through the I2C interface after power-up (see
“3.5.2. Creating a New Configuration for RAM”).
The first step in ordering a custom device is generating
an NVM file which defines the input and output clock
frequencies and signal formats. This is easily done
using the ClockBuilder Desktop software (see "3.1.1.
ClockBuilder™ Desktop Software" on page 16). This
GUI based software generates an NVM file, which is
used by the factory to manufacture custom parts. Each
custom part is marked with a unique part number
identifying the specific configuration (e.g., Si5338CA00100-GM). Consult your local sales representative
for more details on ordering a custom Si5338.
3.5.2. Creating a New Configuration for RAM
Any Si5338 device can be configured by writing to
registers in RAM through the I2C interface. A nonfactory programmed device must be configured in this
manner.
When writing a configuration to RAM, use the following
procedure:
1. Create a device configuration (register map) using
ClockBuilder Desktop (v2.7 or later; see "3.1.1.
ClockBuilder™ Desktop Software" on page 16) or
manually using the equations in “AN411: Configuring
the Si5338”.
a. Configure the frequency plan.
b. Configure the output driver format and supply
voltage.
c. Configure frequency and/or phase inc/dec (if
desired).
d. Configure spread spectrum (if desired).
e. Configure for zero-delay mode (if desired,
see "3.9.5. Zero-Delay Mode" on page 24).
f.
If needed go to the Advanced tab and make
additional configurations.
2. Save the configuration using the Options > Save
Register Map File or Options > Save C code Header
File, or create the register contents by the
conversions listed in AN411.
3.5.3. Writing a Custom Configuration to RAM
Writing a new configuration (register map) to the RAM
consists of pausing the LOL state-machine, writing new
values to the IC accounting for the write-allowed mask
given in "6.1. Register Write-Allowed Mask" on page 28,
validating the input clock or crystal, locking the PLL to
the input with the new configuration, restarting the LOL
state-machine, and calibrating the VCO for robust
operation across temperature. The flow chart in
Figure 9 on page 21 enumerates the details:
Note: The write-allowed mask specifies which bits must be
read and modified before writing the entire register
byte (a.k.a. read-modify-write). “AN428: Jump Start: InSystem, Flash-Based Programming for Silicon Labs’
Timing Products” illustrates the procedure defined in
Section 3.5.2 with ANSI C code.
20
Rev. 0.6
Si5338
Disable Outputs
Set OEB_ALL = 1; reg230[4]
Pause LOL
Set DIS_LOL = 1; reg241[7]
Write new configuration to device
accounting for the write-allowed mask
(See Section 6.1)
Register
Map
Use ClockBuilder
Desktop v2.7 or later
Validate input clock status
Input clocks are
validated with the
LOS alarms. See
Register 218 to
determine which LOS
should be monitored
NO
Is input clock valid?
YES
Configure PLL for locking
Set FCAL_OVRD_EN = 0; reg49[7]
Initiate Locking of PLL
Set SOFT_RESET = 1; reg246[1]
Restart LOL
Set DIS_LOL = 0; reg241[7]
Wait 25 ms
Confirm PLL lock status
NO
PLL is locked when
PLL_LOL, SYS_CAL, and
all other alarms are
cleared
Is PLL locked?
YES
Copy FCAL values to
active registers
Copy registers as follows:
237[1:0] to 47[1:0]
236[7:0] to 46[7:0]
235[7:0] to 45[7:0]
Set 47[7:2] = 000101b
Set PLL to use FCAL values
Set FCAL_OVRD_EN = 1; reg49[7]
Enable Outputs
Set OEB_ALL = 0; reg230[4]
Figure 9. I2C Programming Procedure
Rev. 0.6
21
Si5338
3.5.4. Modifying a MultiSynth Output Divider Ratio/
Frequency Configuration
The output MultiSynth dividers of a configured and
phase-locked Si5338 can be modified without relocking
the PLL (i.e. without following section 3.5.3). This
feature allows any of the four output frequencies to be
modified without disturbing the others.
In this case, only write the set of registers associated
with the output MultiSynth divider (MultiSynth
Frequency Configuration; see Section 6.2). The
feedback MultiSynth must not be modified unless
following the procedure in Section 3.5.3.
To avoid intermediate frequencies, it is recommended
that the output be disabled before changing the divider
ratio (see Register 230).
3.6.1. Using the INTR Pin in Systems with I2C
The INTR output pin is not latched and thus it should not
be a polled input to an MCU but an edge-triggered
interrupt. An MCU can process an interrupt event by
reading the sticky register 247 to see what event
caused the interrupt. The same register can be cleared
by writing zeros to the bits that were set. Individual
interrupt bits can be masked by register 6[4:0].
3.6.2. Using the INTR Pin in Systems without I2C
The INTR pin also provides a useful function in systems
that require a pin-controlled fault indicator. Pre-setting
the interrupt mask register allows the INTR pin to
become an indicator for a specific event, such as LOS
and/or LOL. Therefore, the INTR pin can be used to
indicate a single fault event or even multiple events.
Any output MultiSynth that is reconfigured will lose its
phase alignment with the other outputs. SOFT_RESET
can be used to resynchronize the outputs (see "3.8.
Reset Options" on page 23).
Control & Memory
VDD
3.5.5. Writing a Custom Configuration to NVM
An alternative to ordering an Si5338 with a custom NVM
configuration is to use the field programming kit
(Si5338-PROG-EVB) to write directly to the NVM of a
"blank" Si5338. Since NVM is an OTP memory, it can
only be written once. The default configuration can be
reconfigured by writing to RAM through the I2C interface
(see “3.5.2. Creating a New Configuration for RAM”).
3.6. Status Indicators
A logic-high interrupt pin (INTR) is available to indicate
a loss of signal (LOS) condition, a PLL loss of lock
(PLL_LOL) condition, or that the PLL is in process of
acquiring lock (SYS_CAL). PLL_LOL is held high when
the input frequency drifts beyond the PLL lock range. It
is held low during all other times and during a POR or
soft reset. SYS_CAL is held high during a POR or SOFT
reset so that no chattering occurs during the locking
process. As shown in Figure 10, a status register at
address 218 is available to help identify the exact event
that caused the interrupt pin to become active.
7
218
6
5
4
3
2
PLL_LOL LOS_FDBK LOS_CLKIN
1
Control
1k
NVM
RAM
(OTP)
INTR
Figure 11. INTR Pin with Required Pull-Up
3.7. Output Enable
There are two methods of enabling and disabling the
output drivers: Pin control, and I2C control.
3.7.1. Enabling Outputs Using Pin Control
The Si5338K/L/M devices provide an Output Enable pin
(OEB) as shown in Figure 12. Pulling this pin high will
turn all outputs off. The state of the individual drivers
when turned off is controllable. If an individual output is
set to always on, then the OEB pin will not have an
effect on that driver. Drive state options and always on
are explained in “3.7.2. Enabling Outputs through the
I2C Interface”.
Control & Memory
0
Sys
Cal
Control
System Calibration
(Lock Acquisition)
0 = Enabled
1 = Disabled
NVM
RAM
(OTP)
OEB
Loss Of Signal
Clock Input
Loss Of Signal
Feedback Input
Figure 12. Output Enable Pin (Si5338K/L/M)
Loss Of Lock
Figure 10. Status Register
Figure 11 shows a typical connection with the required
pull-up resistor to VDD.
22
Rev. 0.6
Si5338
3.7.2. Enabling Outputs through the I2C Interface
3.8. Reset Options
Output enable can be controlled through the I2C
interface. As shown in Figure 13, register 230[3:0]
allows control of each individual output driver. Register
230[4] controls all drivers at once. When register 230[4]
is set to disable all outputs, the individual output
enables will have no effect. Registers 110[7:6], 114[7:6],
118[7:6], and 112[7:6] control the output disabled state
as tri-state, low, high, or always on. If always on is set,
that output will always be on regardless of any other
register or chip state. In addition, the always on mode
must be selected for an output that is fed back in a Zero
Delay application.
There are two types of resets on the Si5338, POR and
soft reset. A POR reset automatically occurs whenever
the supply voltage on the VDD is applied.
7
6
5
4
3
2
1
The soft reset is forced by writing 0x02 to register 246.
This bit is not self-clearing, and thus it may read back as
a 1 or a 0. A soft reset will not download any preprogrammed NVM and will not change any register
values in RAM.
The soft reset performs the following sequence:
1. All outputs turn off except if programmed to be
always on.
2. Internal calibrations are done and MultiSynths are
initialized.
0
a. Outputs that are synchronous are phase
aligned (if Rn = 1).
OEB OEB OEB OEB OEB
All
3
2
1
0
230
0 = enable
1 = disable
3. 25 ms is allowed for the PLL to lock (no delay occurs
when FCAL_OVRD_EN = 1).
Bits reserved
4. Turn on all outputs that were turned off in step 1.
3.9. Features of the Si5338
7
6
110
CLK0 OEB
State
114
CLK1 OEB
State
7
6
5
4
3
2
1
0
5
4
3
2
1
0
The Si5338 offers several features and functions that
are useful in many timing applications. The following
paragraphs describe in detail the main features and
typical applications. All of these features can be easily
configured using the ClockBuilder Desktop. See "3.1.1.
ClockBuilder™ Desktop Software" on page 16.
3.9.1. Frequency Increment/Decrement
7
6
118
CLK2 OEB
State
122
CLK3 OEB
State
7
6
5
4
3
2
1
0
5
4
3
2
1
0
00 = disabled tri-state
01 = disabled low
10 = disabled high
11 = always enabled
Each of the output clock frequencies can be
independently stepped up or down in predefined steps
as low as 1 ppm per step and with a resolution of
1 ppm. Setting of the step size and control of the
frequency increment or decrement is accomplished
through the I2C interface. Alternatively, the Si5338 can
be ordered with optional frequency increment (FINC)
and frequency decrement (FDEC) pins for pincontrolled applications. See Table 18 for ordering
information of pin-controlled devices.
Bits used by other functions
Figure 13. Output Enable Control Registers
The frequency increment and decrement feature is
useful in applications requiring a variable clock
frequency (e.g., CPU speed control, FIFO overflow
management, etc.) or in applications where frequency
margining (e.g., fout ±5%) is necessary for design
verification and manufacturing test. Frequency
increment or decrement can be applied as fast as
1.5 MHz when it is done by pin control. When under I2C
control, the frequency increment and decrement update
rate is limited by the I2C bus speed. The magnitude of
the frequency step has 0 ppm error. Frequency steps
are seamless and glitchless.
Rev. 0.6
23
Si5338
3.9.2. Output Phase Increment/Decrement
The Si5338 has a digitally-controlled glitchless phase
increment and decrement feature that allows adjusting
the phase of each output clock in relation to the other
output clocks. The phase of each output clock can be
adjusted with an accuracy of 20 ps over a range of
±45 ns. Setting of the step size and control of the phase
increment or decrement is accomplished through the
I2C interface. Alternatively, the Si5338 can be ordered
with optional phase increment (PINC) and phase
decrement (PDEC) pins for pin-controlled applications.
In pin controlled applications the phase increment and
decrement update rate is as fast as 1.5 MHz. In I2C
applications, the maximum update rate is limited by the
speed of the I2C. See Table 18 for ordering information
of pin-controlled devices.
The phase increment and decrement feature provides a
useful method for fine tuning setup and hold timing
margins or adjusting for mismatched PCB trace lengths.
3.9.3. Initial Phase Offset
Each output clock can be set for its initial phase offset
up to ±45 ns. In order for the initial phase offset to be
applied correctly at power up, the VDDOx output supply
voltage must cross 1.2 V before the VDD (pins 7,24)
core power supply voltage crosses 1.45 V. This applies
to the each driver output individually. A soft_reset will
also guarantee that the programmed Initial Phase Offset
is applied correctly. The initial phase offset only works
on outputs that have their R divider set to 1.
Non-unity settings of R0 will affect the Finc/Fdec step
size at the MultiSynth0 output. For example, if the
MultiSynth0 output step size is 2.56 MHz and R0 = 8,
the step size at the output of R0 will be 2.56 MHz
divided by 8 = .32 MHz. When the Rn divider is set to
non-unity, the initial phase of the CLKn output with
respect to other CLKn outputs is not guaranteed.
3.9.5. Zero-Delay Mode
The Si5338 supports an optional zero delay mode of
operation for applications that require minimal input-tooutput delay. In this mode, one of the device output
clocks is fed back to the feedback input pin (IN4 or IN5/
IN6) to implement an external feedback path essentially
nullifying the delay between the reference input and the
output clocks. Figure 14 shows the Si5338 in a typical
zero-delay configuration. It is generally recommended
that Clk3 be LVDS and that the feedback input be pins 5
and 6. For the differential input configuration to pins 5
and 6, see Figure 3 on page 17. The zero-delay mode
combined with the phase increment/decrement feature
allows unprecedented flexibility in generating clocks
with precise edge alignment.
Si5338
Clk
Input
3.9.4. Output R Divider
Rev. 0.6
R0
Clk0
M1
R1
Clk1
M2
R2
Clk2
M3
R3
Clk3
PLL
P2
When the requested output frequency of a channel is
below 5 MHz, the Rn (n = 0,1,2,3) divider needs to be
set and enabled. This is automatically done in register
maps generated by the ClockBuilder Desktop. When
the Rn divider is active the step size range of the
frequency increment and decrement function will
decrease by the Rn divide ratio. The Rn divider can be
set to {1, 2, 4, 8, 16, 32}.
24
P1
M0
Figure 14. Si5338 in Zero Delay Clock
Generator Mode
Si5338
4. Applications of the Si5338
3.9.6. Spread Spectrum
To help reduce electromagnetic interference (EMI), the
Si5338 supports spread spectrum modulation. The
output clock frequencies can be modulated to spread
energy across a broader range of frequencies, lowering
system EMI. The Si5338 implements spread spectrum
using its patented MultiSynth technology to achieve
previously unattainable precision in both modulation
rate and spreading magnitude as shown in Figure 15.
Spread spectrum can be applied to any output clock,
any clock frequency, and any spread amount. The
device supports center spread (±0.1% to ±5%) and
down spread (–0.1% to –5%). In addition, the device
has extensive on-chip voltage regulation so that power
supply variations do not influence the device’s spreadspectrum clock waveforms.
20
+/- 0%
10
+/- 1%
+/- 2.5%
+/- 5%
0
4.1. Free-Running Clock Generator
Using the internal oscillator (Osc) and an inexpensive
external crystal (XTAL), the Si5338 can be configured
as a free-running clock generator for replacing high-end
and long-lead-time crystal oscillators found on many
printed circuit boards (PCBs). Replacing several crystal
oscillators with a single IC solution helps consolidate the
bill of materials (BOM), reduces the number of
suppliers, and reduces the number of long-lead-time
components on the PCB. In addition, since crystal
oscillators tend to be the least reliable aspect of many
systems, the overall FIT rate improves with the
elimination of each oscillator.
Up to four independent clock frequencies can be
generated at any rate within its supported frequency
range and with any of supported output types. Features,
such as frequency increment and decrement and phase
adjustments on a per-output basis, provide
unprecedented flexibility for PCB designs. Figure 16
shows the Si5338 configured as a free-running clock
generator.
-10
Power Spectrum (dBm)
Because of its flexible architecture, the Si5338 can be
configured to serve several functions in the timing path.
The following sections describe some common
applications.
-20
-30
-40
-50
-60
XTAL
Osc
ref
PLL
M0
R0
F0
M1
R1
F1
M2
R2
F2
M3
R3
F3
-70
-80
-10%
-8%
-6%
-4%
-2%
0%
2%
4%
6%
8%
10%
Relative Frequency
Figure 15. Configurable Spread Spectrum
Si5338
Figure 16. Si5338 as a Free-Running Clock
Generator
Rev. 0.6
25
Si5338
4.2. Synchronous Frequency Translation
4.3. Configurable Buffer and Level
Translator
In other cases, it is useful to generate an output
frequency that is synchronous (or phase-locked) to
another clock frequency. The Si5338 is the ideal choice
for generating up to four clocks with different
frequencies with a fixed phase relationship to an input
reference. Because of its highly precise frequency
synthesis, the Si5338 can generate all four output
frequencies with 0 ppm error to the input reference. The
Si5338 is an ideal choice for applications that have
traditionally required multiple stages of frequency
synthesis to achieve complex frequency translations.
Examples are in broadcast video (e.g., 148.5 MHz to
148.351648351648 MHz), WAN/LAN applications (e.g.
155.52 MHz to 156.25 MHz), and Forward Error
Correction (FEC) applications (e.g., 156.25 MHz to
161.1328125 MHz). Using the input reference selectors,
the Si5338 can select from one of four inputs (IN1/IN2,
IN3, IN4, and IN5/IN6). Figure 17 shows the Si5338
configured as a synchronous clock generator.
Frequencies and multiplication ratios may be entered
into ClockBuilder Desktop using fractional notation to
ensure that the exact scaling ratios can be achieved.
Using the output selectors, the synthesis stage can be
entirely bypassed allowing the Si5338 to act as a
configurable clock buffer/divider with level translation
and selectable inputs. Because of its highly selectable
configuration, virtually any combination is possible. The
configurable output drivers allow four differential
outputs, eight single-ended outputs, or a combination of
both. Figure 18 shows the Si5338 configured as a
flexible clock buffer.
S i5 3 3 8
1
R0
R1
F in *
1
R1
R2
F in *
1
R2
R3
F in *
1
R3
Figure 18. Si5338 as a Configurable Clock
Buffer/Divider with Level Translation
P1
ref
P2
F in *
F in
Si5338
Fin
R0
M0
R0
F0
M1
R1
F1
M2
R2
F2
M3
R3
F3
PLL
4.3.1. Combination Free-Running and Synchronous
Clock Generator
Another application of the Si5338 is in generating both
free-running and synchronous clocks in one device.
This is accomplished by configuring the input and
output selectors for the desired split configuration. An
example of such an application is shown in Figure 19.
Figure 17. Si5338 as a Synchronous Clock
Generator or Frequency Translator
Si5338
R0
F0
R1
F1
M0
R2
F2
M1
R3
F3
Osc
XTAL
F in
P2
ref
PLL
Figure 19. Si5338 In a Free-Running and
Synchronous Clock Generator Application
26
Rev. 0.6
Si5338
5. I2C Interface
Write Operation – Single Byte
Configuration and operation of the Si5338 is controlled
by reading and writing to the RAM space using the I2C
interface. The device operates in slave mode with 7-bit
addressing and can operate in Standard-Mode
(100 kbps) or Fast-Mode (400 kbps) and supports burst
data transfer with auto address increments.
S Slv Addr [6:0] 0 A Reg Addr [7:0] A Data [7:0]
Write Operation - Burst (Auto Address Increment)
S Slv Addr [6:0] 0 A Reg Addr [7:0] A Data [7:0] A Data [7:0] A P
Reg Addr +1
The I2C bus consists of a bidirectional serial data line
(SDA) and a serial clock input (SCL) as shown in
Figure 20. Both the SDA and SCL pins must be
connected to the VDD supply via an external pull-up as
recommended by the I2C specification.
From slave to master
From master to slave
0/1
I2C_LSB
I2C_LSB/PDEC/FDEC
Control
SCL
SDA
I2C Bus
1 – Read
0 – Write
A – Acknowledge (SDA LOW)
N – Not Acknowledge (SDA HIGH)
S – START condition
P – STOP condition
Figure 22. I2C Write Operation
OEB/PINC/FINC
VDD
A P
A read operation is performed in two stages. A data
write is used to set the register address, then a data
read is performed to retrieve the data from the set
address. A read burst operation is also supported. This
is shown in Figure 23.
Figure 20. I2C and Control Signals
Read Operation – Single Byte
The 7-bit device (slave) address of the Si5338 consists
of a 6-bit fixed address plus a user-selectable LSB bit as
shown in Figure 21. The LSB bit is selectable using the
optional I2C_LSB pin which is available as an ordering
option for applications that require more than one
Si5338 on a single I2C bus. Devices without the
I2C_LSB pin option have a fixed 7-bit address of 70h
(111 0000) as shown in Figure 21. Other custom I2C
addresses are also possible. See Table 18 for details on
device ordering information with the optional I2C_LSB
pin.
6
Slave Address
(with I2C_LSB Option)
5
4
3
2
1
S Slv Addr [6:0] 0 A Reg Addr [7:0] A P
S Slv Addr [6:0] 1 A Data [7:0] N P
Read Operation - Burst (Auto Address Increment)
S Slv Addr [6:0] 0 A Reg Addr [7:0] A P
S Slv Addr [6:0] 1 A Data [7:0] A Data [7:0] N P
Reg Addr +1
0
1 1 1 0 0 0 0/1
From slave to master
I2C_LSB pin
6
Slave Address
(without I2C_LSB Option)
1
0
1 1 1 0 0 0
5
4
3
2
0
From master to slave
1 – Read
0 – Write
A – Acknowledge (SDA LOW)
N – Not Acknowledge (SDA HIGH)
S – START condition
P – STOP condition
Figure 23. I2C Read Operation
Figure 21. Si5338 I2C Slave Address
Data is transferred MSB first in 8-bit words as specified
by the I2C specification. A write command consists of a
7-bit device (slave) address + a write bit, an 8-bit
register address, and 8 bits of data as shown in
Figure 22. A write burst operation is also shown where
every additional data word is written using an autoincremented address.
AC and DC electrical specifications for the SCL and
SDA pins are shown in Table 14. The timing
specifications and timing diagram for the I2C bus are
compatible with the I2C-Bus Standard. SDA timeout is
supported for compatibility with SMBus interfaces.
The I2C bus can be operated at a bus voltage of 1.71 to
3.63 V and is 3.3 V tolerant. If a bus voltage of less than
2.5 V is used, register 27[7] = 1 must be written to
maintain compatibility with the I2C bus standard.
Rev. 0.6
27
Si5338
6. Si5338 Registers
This section describes the registers and their usage in
detail. These values are easily configured using
ClockBuilder Desktop (see "3.1.1. ClockBuilder™
Desktop Software" on page 16). See AN428 for a
working example using Silicon Labs' F301 MCU.
6.1. Register Write-Allowed Mask
The masks listed in Table 15 indicate which bits in each
register of the Si5338 can be modified and which bits
cannot. Therefore, these masks are write-allowed or
write-enabled bits. These masks must be used to
perform a read-modify-write on each register.
If a mask is 0x00, all bits in the associated register are
reserved and must remain unchanged. If the mask is
0xFF, all the bits in the register can be changed. All
other registers require a read-modify-write procedure to
write to the registers. ClockBuilder Desktop can be used
to create ANSI C code (Options  Save C code header
file) with the register contents and mask values. AN428
demonstrates the usage of this header file and the readmodify-write procedure.
The following code demonstrates the application of the
above write allowed mask.

Let addr be the address of the register to access.
Let data be the data or value to write to the register
located at addr.
 Let mask be the write-allowed bits defined for the
corresponding register.

// ignore registers with masks of 0x00
if(mask != 0x00){
if(mask == 0xFF){
// do a regular I2C write to the register
// at addr with the desired data value
write_Si5338(addr, data);
} else {
// do a read-modify-write using I2C and
// bit-wise operations
// get the current value from the device at the
// register located at addr
curr_val = read_Si5338(addr);
// clear the bits that are allowed to be
// accessed in the current value of the register
clear_curr_val = curr_val AND (NOT mask);
// clear the bits in the desired data that
// are not allowed to be accessed
clear_new_val = data AND mask;
// combine the cleared values to get the new
// value to write to the desired register
combined = clear_curr_val OR clear_new_val;
write_Si5338(addr, combined);
}
}
28
Rev. 0.6
Si5338
Table 15. Register Write-Allowed Masks
Address (Decimal)
Mask (Hex)
0
0x00
1
0x00
2
0x00
3
0x00
4
0x00
5
0x00
6
0x1D
7
0x00
8
0x00
9
0x00
10
0x00
11
0x00
12
0x00
13
0x00
14
0x00
15
0x00
16
0x00
17
0x00
18
0x00
19
0x00
20
0x00
21
0x00
22
0x00
23
0x00
24
0x00
25
0x00
26
0x00
27
0x80
28
0xFF
*Note: See Figure 9, “I2C Programming Procedure,” on page 21 for the
correct usage of registers 230, 241, and 246. These registers are
not saved in the register map or C code header file from
ClockBuilder Desktop (v2.7 or later).
Rev. 0.6
29
Si5338
Table 15. Register Write-Allowed Masks (Continued)
Address (Decimal)
Mask (Hex)
29
0xFF
30
0xFF
31
0xFF
32
0xFF
33
0xFF
34
0xFF
35
0xFF
36
0x1F
37
0x1F
38
0x1F
39
0x1F
40
0xFF
41
0x7F
42
0x3F
43
0x00
44
0x00
45
0xFF
46
0xFF
47
0x3F
48
0xFF
49
0xFF
50
0xFF
51
0xFF
52
0x7F
53
0xFF
54
0xFF
55
0xFF
56
0xFF
57
0xFF
*Note: See Figure 9, “I2C Programming Procedure,” on page 21 for the
correct usage of registers 230, 241, and 246. These registers are
not saved in the register map or C code header file from
ClockBuilder Desktop (v2.7 or later).
30
Rev. 0.6
Si5338
Table 15. Register Write-Allowed Masks (Continued)
Address (Decimal)
Mask (Hex)
58
0xFF
59
0xFF
60
0xFF
61
0xFF
62
0x3F
63
0x7F
64
0xFF
65
0xFF
66
0xFF
67
0xFF
68
0xFF
69
0xFF
70
0xFF
71
0xFF
72
0xFF
73
0x3F
74
0x7F
75
0xFF
76
0xFF
77
0xFF
78
0xFF
79
0xFF
80
0xFF
81
0xFF
82
0xFF
83
0xFF
84
0x3F
85
0x7F
86
0xFF
*Note: See Figure 9, “I2C Programming Procedure,” on page 21 for the
correct usage of registers 230, 241, and 246. These registers are
not saved in the register map or C code header file from
ClockBuilder Desktop (v2.7 or later).
Rev. 0.6
31
Si5338
Table 15. Register Write-Allowed Masks (Continued)
Address (Decimal)
Mask (Hex)
87
0xFF
88
0xFF
89
0xFF
90
0xFF
91
0xFF
92
0xFF
93
0xFF
94
0xFF
95
0x3F
96
0x00
97
0xFF
98
0xFF
99
0xFF
100
0xFF
101
0xFF
102
0xFF
103
0xFF
104
0xFF
105
0xFF
106
0xBF
107
0xFF
108
0x7F
109
0xFF
110
0xFF
111
0xFF
112
0x7F
113
0xFF
114
0xFF
115
0xFF
*Note: See Figure 9, “I2C Programming Procedure,” on page 21 for the
correct usage of registers 230, 241, and 246. These registers are
not saved in the register map or C code header file from
ClockBuilder Desktop (v2.7 or later).
32
Rev. 0.6
Si5338
Table 15. Register Write-Allowed Masks (Continued)
Address (Decimal)
Mask (Hex)
116
0xFF
117
0xFF
118
0xFF
119
0xFF
120
0xFF
121
0xFF
122
0xFF
123
0xFF
124
0xFF
125
0xFF
126
0xFF
127
0xFF
128
0xFF
129
0x0F
130
0x0F
131
0xFF
132
0xFF
133
0xFF
134
0xFF
135
0xFF
136
0xFF
137
0xFF
138
0xFF
139
0xFF
140
0xFF
141
0xFF
142
0xFF
143
0xFF
144
0xFF
*Note: See Figure 9, “I2C Programming Procedure,” on page 21 for the
correct usage of registers 230, 241, and 246. These registers are
not saved in the register map or C code header file from
ClockBuilder Desktop (v2.7 or later).
Rev. 0.6
33
Si5338
Table 15. Register Write-Allowed Masks (Continued)
Address (Decimal)
Mask (Hex)
145
0x00
146
0x00
147
0x00
148
0x00
149
0x00
150
0x00
151
0x00
152
0xFF
153
0xFF
154
0xFF
155
0xFF
156
0xFF
157
0xFF
158
0x0F
159
0x0F
160
0xFF
161
0xFF
162
0xFF
163
0xFF
164
0xFF
165
0xFF
166
0xFF
167
0xFF
168
0xFF
169
0xFF
170
0xFF
171
0xFF
172
0xFF
173
0xFF
*Note: See Figure 9, “I2C Programming Procedure,” on page 21 for the
correct usage of registers 230, 241, and 246. These registers are
not saved in the register map or C code header file from
ClockBuilder Desktop (v2.7 or later).
34
Rev. 0.6
Si5338
Table 15. Register Write-Allowed Masks (Continued)
Address (Decimal)
Mask (Hex)
174
0xFF
175
0xFF
176
0xFF
177
0xFF
178
0xFF
179
0xFF
180
0xFF
181
0x0F
182
0xFF
183
0xFF
184
0xFF
185
0xFF
186
0xFF
187
0xFF
188
0xFF
189
0xFF
190
0xFF
191
0xFF
192
0xFF
193
0xFF
194
0xFF
195
0xFF
196
0xFF
197
0xFF
198
0xFF
199
0xFF
200
0xFF
201
0xFF
202
0xFF
*Note: See Figure 9, “I2C Programming Procedure,” on page 21 for the
correct usage of registers 230, 241, and 246. These registers are
not saved in the register map or C code header file from
ClockBuilder Desktop (v2.7 or later).
Rev. 0.6
35
Si5338
Table 15. Register Write-Allowed Masks (Continued)
Address (Decimal)
Mask (Hex)
203
0x0F
204
0xFF
205
0xFF
206
0xFF
207
0xFF
208
0xFF
209
0xFF
210
0xFF
211
0xFF
212
0xFF
213
0xFF
214
0xFF
215
0xFF
216
0xFF
217
0xFF
218
0x00
219
0x00
220
0x00
221
0x00
222
0x00
223
0x00
224
0x00
225
0x00
226
0x04
227
0x00
228
0x00
229
0x00
230*
0xFF
231
0x00
*Note: See Figure 9, “I2C Programming Procedure,” on page 21 for the
correct usage of registers 230, 241, and 246. These registers are
not saved in the register map or C code header file from
ClockBuilder Desktop (v2.7 or later).
36
Rev. 0.6
Si5338
Table 15. Register Write-Allowed Masks (Continued)
Address (Decimal)
Mask (Hex)
232
0x00
233
0x00
234
0x00
235
0x00
236
0x00
237
0x00
238
0x00
239
0x00
240
0x00
241*
0xFF
242
0x02
243
0x00
244
0x00
245
0x00
246*
0xFF
247
0x00
248
0x00
249
0x00
250
0x00
251
0x00
252
0x00
253
0x00
254
0x00
255
0xFF
256
0x00
257
0x00
258
0x00
259
0x00
260
0x00
*Note: See Figure 9, “I2C Programming Procedure,” on page 21 for the
correct usage of registers 230, 241, and 246. These registers are
not saved in the register map or C code header file from
ClockBuilder Desktop (v2.7 or later).
Rev. 0.6
37
Si5338
Table 15. Register Write-Allowed Masks (Continued)
Address (Decimal)
Mask (Hex)
261
0x00
262
0x00
263
0x00
264
0x00
265
0x00
266
0x00
267
0x00
268
0x00
269
0x00
270
0x00
271
0x00
272
0x00
273
0x00
274
0x00
275
0x00
276
0x00
277
0x00
278
0x00
279
0x00
280
0x00
281
0x00
282
0x00
283
0x00
284
0x00
285
0x00
286
0x00
287
0xFF
288
0xFF
289
0xFF
*Note: See Figure 9, “I2C Programming Procedure,” on page 21 for the
correct usage of registers 230, 241, and 246. These registers are
not saved in the register map or C code header file from
ClockBuilder Desktop (v2.7 or later).
38
Rev. 0.6
Si5338
Table 15. Register Write-Allowed Masks (Continued)
Address (Decimal)
Mask (Hex)
290
0xFF
291
0xFF
292
0xFF
293
0xFF
294
0xFF
295
0xFF
296
0xFF
297
0xFF
298
0xFF
299
0x0F
300
0x00
301
0x00
302
0x00
303
0xFF
304
0xFF
305
0xFF
306
0xFF
307
0xFF
308
0xFF
309
0xFF
310
0xFF
311
0xFF
312
0xFF
313
0xFF
314
0xFF
315
0x0F
316
0x00
317
0x00
318
0x00
*Note: See Figure 9, “I2C Programming Procedure,” on page 21 for the
correct usage of registers 230, 241, and 246. These registers are
not saved in the register map or C code header file from
ClockBuilder Desktop (v2.7 or later).
Rev. 0.6
39
Si5338
Table 15. Register Write-Allowed Masks (Continued)
Address (Decimal)
Mask (Hex)
319
0xFF
320
0xFF
321
0xFF
322
0xFF
323
0xFF
324
0xFF
325
0xFF
326
0xFF
327
0xFF
328
0xFF
329
0xFF
330
0xFF
331
0x0F
332
0x00
333
0x00
334
0x00
335
0xFF
336
0xFF
337
0xFF
338
0xFF
339
0xFF
340
0xFF
341
0xFF
342
0xFF
343
0xFF
344
0xFF
345
0xFF
346
0xFF
347
0x0F
*Note: See Figure 9, “I2C Programming Procedure,” on page 21 for the
correct usage of registers 230, 241, and 246. These registers are
not saved in the register map or C code header file from
ClockBuilder Desktop (v2.7 or later).
40
Rev. 0.6
Si5338
Table 15. Register Write-Allowed Masks (Continued)
Address (Decimal)
Mask (Hex)
348
0x00
349
0x00
350
0x00
*Note: See Figure 9, “I2C Programming Procedure,” on page 21 for the
correct usage of registers 230, 241, and 246. These registers are
not saved in the register map or C code header file from
ClockBuilder Desktop (v2.7 or later).
Rev. 0.6
41
Si5338
6.2. Register Categories
This is a list of registers needed to define the Configuration of a device. Set the PAGEBIT to access registers with
addresses greater than 255.
Address (Decimal)
Bits
6
4:0
27
7:6
27
7
28 - 30
7:0
Input Mux Configuration
31 - 39
7:0
Output Configuration
40
7:0
41
6:0
42
4:0
47
5:2
48
7:0
49
6:0
50
7:0
51
7:4, 2:0
52
6:0
53-61
7:0
62
5:0
63
6:0
64-72
7:0
73
5:0
74
6:0
75-83
7:0
84
5:0
85
6:0
86-94
7:0
95
5:0
97-105
7:0
106
5:0
107 - 110
7:0
MultiSynth0 Phase inc/dec, SS Configuration, drive state
111 - 114
7:0
MultiSynth1 Phase inc/dec, SS Configuration, drive state
115 - 118
7:0
MultiSynth2 Phase inc/dec, SS Configuration, drive state
42
Function
Mask bits for LOS_CLKIN,LOS_FB, LOL, SYS_CAL
I2C Configuration
Output Driver Trim Bits
Input Configuration
PLL Configuration
MultiSynth0 Freq inc/dec, SS, Phase inc/dec Configuration
MultiSynth0 frequency Configuration
MultiSynth1 frequency Configuration
MultiSynth2 frequency Configuration
MultiSynth3 frequency Configuration
MultiSynthN Feedback divider Configuration
Rev. 0.6
Si5338
Address (Decimal)
Bits
Function
119
7:0
120
6:0
121 - 122
7:0
123-128
7:0
129
3:0
130
6:0
131 - 144
7:0
152 - 173
7:0
MultiSynth1 freq inc/dec Configuration
174 - 195
7:0
MultiSynth2 freq inc/dec Configuration
196 - 216
7:0
217
6:0
241
7:0
287
7:0
288
6:0
289
7:0
290
6:0
291
7:0
292
7:0
293
7:0
294
7:0
295
6:0
296
7:0
297
6:0
298
7:0
299
7:0
MultiSynth3 Phase inc/dec, SS Configuration, drive state
MultiSynth0 freq inc/dec Configuration, ID config
MultiSynth3 freq inc/dec Configuration
Reserved - set to 0x65 if not factory-programmed.
MultiSynth0 spread spectrum Configuration
Rev. 0.6
43
Si5338
Address (Decimal)
Bits
303
7:0
304
6:0
305
7:0
306
6:0
307
7:0
308
7:0
309
7:0
310
7:0
311
6:0
312
7:0
313
6:0
314
7:0
315
7:0
319
7:0
320
6:0
321
7:0
322
6:0
323
7:0
324
7:0
325
7:0
326
7:0
327
6:0
328
7:0
329
6:0
330
7:0
331
7:0
44
Function
MultiSynth1 spread spectrum Configuration
MultiSynth2 spread spectrum Configuration
Rev. 0.6
Si5338
Address (Decimal)
Bits
335
7:0
336
6:0
337
7:0
338
6:0
339
7:0
340
7:0
341
7:0
342
7:0
343
6:0
344
7:0
345
6:0
346
7:0
347
7:0
Function
MultiSynth3 spread spectrum Configuration
Rev. 0.6
45
Si5338
6.3. Register Summary
Table 16. Register Summary
Register
7
6
5
4
3
2
0
1
0
REVID[2:0]
PLL_LOL_
MASK
6
27
I2C_1P8_SEL
28
FDBK_PDN
LOS_FDBK_
MASK
LOS_CLKIN_
MASK
SYS_CAL_
MASK
I2C_ADDR[6:0]
P2DIV_IN[0]
P1DIV_IN[2:0]
XTAL_FREQ[1:0]
29
PFD_IN_REF[2:0]
P1DIV_IN[4:3]
P1DIV[2:0]
30
PFD_IN_FB[2:0]
P2DIV_IN[2:1]
P2DIV[2:0]
31
R0DIV_IN[2:0]
R0DIV[2:0]
MS0_PDN
DRV0_PDN
32
R1DIV_IN[2:0]
R1DIV[2:0]
MS1_PDN
DRV1_PDN
33
R2DIV_IN[2:0]
R2DIV[2:0]
MS2_PDN
DRV2_PDN
34
R3DIV_IN[2:0]
R3DIV[2:0]
MS3_PDN
DRV3_PDN
35
DRV3_VDDO[1:0]
DRV2_VDDO[1:0]
DRV1_VDDO[1:0]
DRV0_VDDO[1:0]
36
DRV0_INV[1:0]
DRV0_FMT[2:0]
37
DRV1_INV[1:0]
DRV1_FMT[2:0]
38
DRV2_INV[1:0]
DRV2_FMT[2:0]
39
DRV3_INV[1:0]
DRV3_FMT[2:0]
40
DRV1_TRIM[2:0]
DRV0_TRIM[4:0]
41
DRV2_TRIM[4:0]
DRV1_TRIM[4:3]
42
DRV3_TRIM[4:0]
45
FCAL_OVRD[7:0]
46
FCAL_OVRD[15:8]
47
FCAL_OVRD[17:16]
48
PFD_EXTFB
49
FCAL_OVRD_EN
50
51
52
PLL_KPHI[6:0]
VCO_GAIN[2:0]
RSEL[1:0]
PLL_ENABLE[1:0]
MS3_HS
MSCAL[5:0]
MS2_HS
MS1_HS
MS0_FIDCT[1:0]
MS0_HS
MS0_FIDDIS
53
MS0_P1[7:0]
54
MS0_P1[15:8]
55
MS0_P2[5:0]
MS_PEC[2:0]
MS0_SSMODE[1:0]
MS0_PHIDCT[1:0]
MS0_P1[17:16]
56
MS0_P2[13:6]
57
MS0_P2[21:14]
58
MS0_P2[29:22]
59
MS0_P3[7:0]
46
BWSEL[1:0]
Rev. 0.6
Si5338
Table 16. Register Summary (Continued)
Register
7
6
5
4
3
60
MS0_P3[15:8]
61
MS0_P3[23:16]
62
63
MS1_FIDCT[1:0]
MS1_FIDDIS
MS1_P1[7:0]
65
MS1_P1[15:8]
66
0
MS1_PHIDCT[1:0]
MS1_P1[17:16]
MS1_P2[13:6]
68
MS1_P2[21:14]
69
MS1_P2[29:22]
70
MS1_P3[7:0]
71
MS1_P3[15:8]
72
MS1_P3[23:16]
73
MS1_P3[29:24]
MS2_FRCTL[1:0]
MS2_FIDDIS
75
MS2_P1[7:0]
76
MS2_P1[15:8]
77
MS2_SSMODE[1:0]
MS2_P2[5:0]
MS2_PHIDCT[1:0]
MS2_P1[17:16]
78
MS2_P2[13:6]
79
MS2_P2[21:14]
80
MS2_P2[29:22]
81
MS2_P3[7:0]
82
MS2_P3[15:8]
83
MS2_P3[23:16]
84
MS2_P3[29:24]
MS3_FIDCTL[1:0]
MS3_FIDDIS
86
MS3_P1[7:0]
87
MS3_P1[15:8]
88
MS1_SSMODE[1:0]
MS1_P2[5:0]
67
85
1
MS0_P3[29:24]
64
74
2
MS3_SSMODE[1:0]
MS3_P2[5:0]
MS3_PHIDCTL[1:0]
MS3_P1DIV[17:16]
89
MS3_P2[13:6]
90
MS3_P2[21:14]
91
MS3_P2[29:22]
92
MS3_P3[7:0]
93
MS3_P3[15:8]
94
MS3_P3[23:16]
95
MS3_P3[29:24]
Rev. 0.6
47
Si5338
Table 16. Register Summary (Continued)
Register
7
6
5
4
3
97
MSN_P1[7:0]
98
MSN_P1[15:8]
99
MSN_P2[5:0]
MSN_P2[13:6]
101
MSN_P2[21:14]
102
MSN_P2[29:22]
103
MSN_P3[7:0]
104
MSN_P3[15:8]
105
MSN_P3[23:16]
106
MSN_P3[29:24]
107
MS0_PHOFF[7:0]
108
MS0_PHOFF[14:8]
109
MS0_PHSTEP[7:0]
CLK0_DISST[1:0]
111
MS0_PHSTEP[13:8]
MS1_PHOFF[7:0]
112
MS1_PHOFF[14:8]
113
114
MS1_PHSTEP[7:0]
CLK1_DISST[1:0]
115
MS1_PHSTEP[13:8]
MS2_PHOFF[7:0]
116
MS2_PHOFF[14:8]
117
118
MS2_PHSTEP[7:0]
CLK2_DISST[1:0]
119
MS2_PHSTEP[13:8]
MS3_PHOFF[7:0]
120
MS3_PHOFF[14:8]
121
122
1
MS3_PHSTEP[7:0]
CLK3_DISST[1:0]
MS3_PHSTEP[13:8]
123
MS0_FIDP1[7:0]
124
MS0_FIDP1[15:8]
125
MS0_FIDP1[23:16]
126
MS0_FIDP1[31:24]
127
MS0_FIDP1[39:32]
128
MS0_FIDP1[47:40]
129
MS0_FIDP1[51:48]
130
MS0_FIDP2[51:48]
131
MS0_FIDP2[47:40]
132
MS0_FIDP2[39:32]
48
0
MSN_P1[17:16]
100
110
2
Rev. 0.6
Si5338
Table 16. Register Summary (Continued)
Register
7
6
5
4
3
133
MS0_FIDP2[31:24]
134
MS0_FIDP2[23:16]
135
MS0_FIDP2[15:8]
136
MS0_FIDP2[7:0]
137
MS0_FIDP3[7:0]
138
MS0_FIDP3[15:8]
139
MS0_FIDP3[23:16]
140
MS0_FIDP3[31:24]
141
MS0_FIDP3[39:32]
142
MS0_FIDP3[47:40]
143
MS0_FIDP3[51:48]
144
MS0_ALL
2
1
0
MS0_FIDP3[62:56]
152
MS1_FIDP1[7:0]
153
MS1_FIDP1[15:8]
154
MS1_FIDP1[23:16]
155
MS1_FIDP1[31:24]
156
MS1_FIDP1[39:32]
157
MS1_FIDP1[47:40]
158
MS1_FIDP1[51:48]
159
MS1_FIDP2[51:48]
160
MS1_FIDP2[47:40]
161
MS1_FIDP2[39:32]
162
MS1_FIDP2[31:24]
163
MS1_FIDP2[23:16]
164
MS1_FIDP2[15:8]
165
MS1_FIDP2[7:0]
166
MS1_FIDP3[7:0]
167
MS1_FIDP3[15:8]
168
MS1_FIDP3[23:16]
169
MS1_FIDP3[31:24]
170
MS1_FIDP3[39:32]
171
MS1_FIDP3[47:40]
172
MS1_FIDP3[51:48]
173
MS1_FIDP3[62:56]
174
MS2_FIDP1[7:0]
175
MS2_FIDP1[15:8]
Rev. 0.6
49
Si5338
Table 16. Register Summary (Continued)
Register
7
6
5
4
3
176
MS2_FIDP1[23:16]
177
MS2_FIDP1[31:24]
178
MS2_FIDP1[39:32]
179
MS2_FIDP1[47:40]
2
1
180
MS2_FIDP1[51:48]
181
MS2_FIDP2[51:48]
182
MS2_FIDP2[47:40]
183
MS2_FIDP2[39:32]
184
MS2_FIDP2[31:24]
185
MS2_FIDP2[23:16]
186
MS2_FIDP2[15:8]
187
MS2_FIDP2[7:0]
188
MS2_FIDP3[7:0]
189
MS2_FIDP3[15:8]
190
MS2_FIDP3[23:16]
191
MS2_FIDP3[31:24]
192
MS2_FIDP3[39:32]
193
MS2_FIDP3[47:40]
194
MS2_FIDP3[51:48]
195
MS2_FIDP3[62:56]
196
MS3_FIDP1[7:0]
197
MS3_FIDP1[15:8]
198
MS3_FIDP1[23:16]
199
MS3_FIDP1[31:24]
200
MS3_FIDP1[39:32]
201
MS3_FIDP1[47:40]
202
MS3_FIDP1[51:48]
203
MS3_FIDP2[51:48]
204
MS3_FIDP2[47:40]
205
MS3_FIDP2[39:32]
206
MS3_FIDP2[31:24]
207
MS3_FIDP2[23:16]
208
MS3_FIDP2[15:8]
209
MS3_FIDP2[7:0]
210
MS3_FIDP3[7:0]
211
MS3_FIDP3[15:8]
50
Rev. 0.6
0
Si5338
Table 16. Register Summary (Continued)
Register
7
6
5
4
3
212
MS3_FIDP3[23:16]
213
MS3_FIDP3[31:24]
214
MS3_FIDP3[39:32]
215
MS3_FIDP3[47:40]
216
MS3_FIDP3[51:48]
217
2
PLL_LOL
LOS_FDBK
LOS_CLKIN
230
OEB_ALL
OEB_3
OEB_2
235
FCAL[7:0]
236
FCAL[15:8]
237
SYS_CAL
OEB_1
DIS_LOL
DCLK_DIS
246
SOFT_RESET
247
PLL_LOL_STK
LOS_FDBK_
STK
LOS_CLKIN_
STK
255
SYS_CAL_STK
PAGE_SEL
287
MS0_SSUPP2[7:0]
288
MS0_SSUPP2[14:8]
289
MS0_SSUPP3[7:0]
290
MS0_SSUPP3[14:8]
291
MS0_SSUPP1[7:0]
MS0_SSUDP1[3:0]
MS0_SSUPP1[11:8]
293
MS0_SSUDP1[11:4]
294
MS0_SSDNP2[7:0]
295
MS0_SSDNP2[14:8]
296
MS0_SSDNP3[7:0]
297
MS0_SSDNP3[14:8]
298
MS0_SSDNP1[7:0]
299
MS0_SSDNP1[11:8]
303
MS1_SSUPP2[7:0]
304
MS1_SSUPP2[14:8]
305
MS1_SSUPP3[7:0]
306
MS1_SSUPP3[14:8]
307
308
OEB_0
FCAL[17:16]
242
292
0
MS3_FIDP3[62:56]
218
241
1
MS1_SSUPP1[7:0]
MS1_SSUDP1[3:0]
MS1_SSUPP1[11:8]
Rev. 0.6
51
Si5338
Table 16. Register Summary (Continued)
Register
7
6
5
4
3
309
MS1_SSUDP1[11:4]
310
MS1_SSDNP2[7:0]
311
MS1_SSDNP3[7:0]
313
MS1_SSDNP3[14:8]
314
MS1_SSDNP1[7:0]
315
MS1_SSDNP1[11:8]
319
MS2_SSUPP2[7:0]
320
MS2_SSUPP2[14:8]
321
MS2_SSUPP3[7:0]
322
MS2_SSUPP3[14:8]
323
MS2_SSUPP1[7:0]
MS2_SSUDP1[3:0]
MS2_SSUPP1[11:8]
325
MS2_SSUDP1[11:4]
326
MS2_SSDNP2[7:0]
327
MS2_SSDNP2[14:8]
328
MS2_SSDNP3[7:0]
329
MS2_SSDNP3[14:8]
330
MS2_SSDNP1[7:0]
331
MS2_SSDNP1[11:8]
335
MS3_SSUPP2[7:0]
336
MS3_SSUPP2[14:8]
337
MS3_SSUPP3[7:0]
338
MS3_SSUPP3[14:8]
339
340
MS3_SSUPP1[7:0]
MS3_SSUDP1[3:0]
MS3_SSUPP1[11:8]
341
MS3_SSUDP1[11:4]
342
MS3_SSDNP2[7:0]
343
344
MS3_SSDNP2[14:8]
MS3_SSDNP3[7:0]
345
346
MS3_SSDNP3[14:8]
MS3_SSDNP1[7:0]
347
52
1
MS1_SSDNP2[14:8]
312
324
2
MS3_SSDNP1[11:8]
Rev. 0.6
0
Si5338
6.4. Register Descriptions
In many registers, the byte reset value contains one or more “x”s because a factory-programmed device can have
multiple values for these bits.
Register 0.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
REVID[2:0]
Type
R
D0
Reset value = xxxx xxxx
Bit
Name
7:3
Reserved
2:0
REVID[2:0]
Function
Reserved.
Device Revision ID.
Rev. 0.6
53
Si5338
Register 6.
Bit
Name
D7
D6
D5
D4
D3
D2
PLL_LOL_MASK LOS_FDBK_MASK LOS_CLKIN_MASK
Type
R/W
R/W
R/W
D1
D0
Reserved
SYS_CAL_MASK
R/W
Reset value = xxxx xxxx
Bit
Name
7:5
Reserved
4
Reserved. Must only write 000b to these bits.
Mask Bit for PLL_LOL.
When true, the PLL_LOL bit (Register 218) will not cause an interrupt. See also
Register 247.
0: PLL Loss of Lock (LOL) triggers active interrupt on INTR output pin.
1: PLL Loss of Lock (LOL) ignored in generating interrupt output.
3
Mask Bit for Loss of Signal on IN4 or IN5,6.
When true, the LOS_FDBK bit (Register 218) will not cause an interrupt. See
LOS_FDBK_MASK also Register 247.
0: FDBK LOS triggers active interrupt on INTR output pin.
1: FDBK LOS ignored in generating interrupt output.
2
Mask Bit for Loss of Signal on IN1,2 or IN3.
When true, the LOS_CLKIN bit (Register 218) will not cause an interrupt.
LOS_CLKIN_MASK See also Register 247.
0: CLKIN LOS triggers active interrupt on INTR output pin.
1: CLKIN LOS ignored in generating interrupt output.
1
0
54
PLL_LOL_MASK
Function
Reserved
SYS_CAL_MASK
Reserved. Must only write 0 to this bit.
Chip Calibration Mask Bit.
When true, the SYS_CAL bit (Register 218) will not cause an interrupt. See also
Register 247.
0:PLL self-calibration triggers active interrupt on INTR output pin.
1:PLL self-calibration ignored in generating interrupt output.
Rev. 0.6
Si5338
Register 27.
Bit
D7
D6
D5
D4
Name I2C_1P8_SEL
Type
D3
D2
D1
D0
I2C_ADDR[6:0]
R/W
R/W*
Reset value = xxxx xxxx
Bit
Name
Function
I2C Reference VDD.
7
6:0*
I2C_1P8_SEL External I2C VDD 0 = 3.3 V/2.5 V, 1 = 1.8 V.
0: 3.3 V/2.5 V (default)
1: 1.8 V
7-Bit I2C Address.
If and only if there is an I2C_LSB pin, the actual I2C LSB address is the logical “or” of
the bit in position 0 with the state of the I2C_LSB pin. Otherwise, the actual I2C_LSB
I2C addresses may be requested but
I2C_ADDR[6:0] is the LSB of this 7-bit address. Custom 7-bit
2
must be even numbers if pin control of the I C address is to be implemented. For
example, if the I2C address = 70h, the I2C_LSB pin can change the LSB from 0 to 1.
However, if the I2C address = 71h, the I2C_LSB pin will have no effect upon the I2C
address.
*Note: Although these bits are R/W, writing them is not supported. Custom I2C addresses can be set at the factory. Contact
your local sales office for details.
Rev. 0.6
55
Si5338
Register 28.
Bit
D7
Name
Type
R/W
D6
D5
D4
D3
D2
D1
D0
P2DIV_IN[0]
P1DIV_IN[2:0]
XTAL_FREQ[1:0]
R/W
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
7:6
Reserved
5
4:2
1:0
56
Function
Reserved. Must only write a 00 to these bits.
P2DIV_IN[0]
This bit and Register 30[4:3] create a 3-bit field that selects the input to the P2
divider [reg30[4:3] reg28[5]] = P2DIV_IN[2:0].
000b: Clock from IN5,IN6 is input to P2 divider
011b: Clock from IN4 is input to P2
100b: No clock is input to P2
All other bit values are reserved.
P1DIV_IN[2:0]
These three bits are combined with Register 29[4:3] and create a 5-bit field that
selects the input to the P1 divider [reg29[4:3] reg28[4:2]] = P1DIV_IN[4:0].
00000b: Clock from IN1,IN2 selected
01010b: Clock from IN3 selected
10101b: Crystal oscillator selected
All other bit values are reserved and should not be written.
XTAL_FREQ[1:0]
Crystal Frequency Range.
Select Xtal Frequency that you are using. For more information on using crystals,
see “AN360: Crystal Selection Guide for Si533x/5x Devices”.
0: 8–11 MHz
1: 11–19 MHz
2: 19–26 MHz
3: 26–30 MHz
Rev. 0.6
Si5338
Register 29.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
PFD_IN_REF[2:0]
P1DIV_IN[4:3]
P1DIV[2:0]
Type
R/W
R/W
R/W
D0
Reset value = xxxx xxxx
Bit
7:5
4:3
2:0
Name
PFD_IN_REF[2:0]
P1DIV_IN[4:3]
P1DIV[2:0]
Function
Selects the input clock to be provided to the reference input of PLL Phase
Frequency Detector (PFD).
0: P1DIV_IN selected
1: P2DIV_IN selected
2: P1DIV_OUT (P1 divider output) selected
3: P2DIV_OUT (P2 divider output) selected
4: XOCLK selected
5: No Clock selected
6: Reserved
7: Reserved
These two bits along with reg28[4:2] create a 5-bit field that selects the input to
the P1 divider [reg29[4:3] reg28[4:2]] = P1DIV_IN[4:0].
00000b: Clock from IN,2 selected
01010b: Clock from IN3 selected
10101b: Crystal oscillator selected
All other bit values are reserved
Sets the value of the P1 divider.
0: Divide by 1
1: Divide by 2
2: Divide by 4
3: Divide by 8
4: Divide by 16
5: Divide by 32
Rev. 0.6
57
Si5338
Register 30.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
PFD_IN_FB[2:0]
P2DIV_IN[2:1]
P2DIV[2:0]
Type
R/W
R/W
R/W
D0
Reset value = xxxx xxxx
Bit
7:5
4:3
2:0
58
Name
Function
PFD_IN_FB[2:0]
Selects the external input applied to the PFD feedback input. See also Register
48[7].
0: P2DIV_IN (fbclk)
1: P1DIV_IN (refclk)
2: P2DIV_OUT (P2 divider output) selected
3: P1DIV_OUT (P1 divider output) selected
4: Reserved
5: No Clock selected
6: Reserved
7: Reserved
P2DIV_IN[2:1]
These two bits and Register 28[5] create a 3-Bit field that selects the input to the
P2 divider [reg30[4:3] reg28[5]] = P2DIV_IN[2:0].
000b: Clock from IN5,IN6 is input to P2 divider
011b: Clock from IN4 is input to P2
100b: No clock is input to P2
All other bit values are reserved.
P2DIV[2:0]
Sets the value of the P2 the divider.
0: Divide by 1
1: Divide by 2
2: Divide by 4
3: Divide by 8
4: Divide by 16
5: Divide by 32
Rev. 0.6
Si5338
Register 31.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
R0DIV_IN[2:0]
R0DIV[2:0]
MS0_PDN
DRV0_PDN
Type
R/W
R/W
R/W
R/W
Reset value = xxxx xxxx
Bit
7:5
Name
R0DIV_IN[2:0]
Function
Selects the input to the R0 divider. R0 divider output goes to CLK0.
0: P2DIV_IN (fbclk) selected
1: P1DIV_IN (refclk) selected
2: P2DIV_OUT (P2 divider output) selected
3: P1DIV_OUT (P1 divider output) selected
4: XOCLK selected
5: MultiSynth0 output selected
6: MultiSynth0 output selected
7: No Clock selected
4:2
R0DIV[2:0]
CLK0 R0 Output Divider.
0: Divide by 1
1: Divide by 2
2: Divide by 4
3: Divide by 8
4: Divide by 16
5: Divide by 32
1
MS0_PDN
MultiSynth0 Power Down.
0: MS0 MultiSynth powered up
1: MS0 MultiSynth powered down
0
DRV0_PDN
R0 and CLK0 Power Down.
0: R0 output divider and CLK0 driver powered up
1: R0 output divider and CLK0 driver powered down
Rev. 0.6
59
Si5338
Register 32.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
R1DIV_IN[2:0]
R1DIV[2:0]
MS1_PDN
DRV1_PDN
Type
R/W
R/W
R/W
R/W
Reset value = xxxx xxxx
Bit
7:5
60
Name
R1DIV_IN[2:0]
Function
Selects the input to the R1 divider. R1 divider output goes to CLK1.
0: P2DIV_IN (fbclk) selected
1: P1DIV_IN (refclk) selected
2: P2DIV_OUT (P2 divider output) selected
3: P1DIV_OUT (P1 divider output) selected
4: XOCLK selected
5: MultiSynth0 output selected
6: MultiSynth1 output selected
7: No Clock selected
4:2
R1DIV[2:0]
CLK1 R1 Output Divider.
0: Divide by 1
1: Divide by 2
2: Divide by 4
3: Divide by 8
4: Divide by 16
5: Divide by 32
1
MS1_PDN
MultiSynth1 Power Down.
0: MultiSynth1 is powered up
1: MultiSynth1 is powered down
0
DRV1_PDN
R1 and CLK1 Power Down.
0: R1 output divider and CLK1 driver powered up
1: R1 output divider and CLK1 driver powered down
Rev. 0.6
Si5338
Register 33.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
R2DIV_IN[2:0]
R2DIV[2:0]
MS2_PDN
DRV2_PDN
Type
R/W
R/W
R/W
R/W
Reset value = xxxx xxxx
Bit
7:5
Name
R2DIV_IN[2:0]
Function
Selects the input to the R2 divider. R2 divider output goes to CLK2.
0: P2DIV_IN (fbclk) selected
1: P1DIV_IN (refclk) selected
2: P2DIV_OUT (P2 divider output) selected
3: P1DIV_OUT (P1 divider output) selected
4: XOCLK selected
5: MultiSynth0 output selected
6: MultiSynth2 output selected
7: No Clock selected
CLK2 R2 Output Divider.
4:2
R2DIV[2:0]
1
MS2_PDN
0: Divide by 1
1: Divide by 2
2: Divide by 4
3: Divide by 8
4: Divide by 16
5: Divide by 32
MultiSynth2 Power Down.
0: MultiSynth2 powered up
1: MultiSynth2 powered down
R2 and CLK2 Power Down.
0
DRV2_PDN
0: R2 output divider and CLK2 driver powered up
1: R2 output divider and CLK2 driver powered down
Rev. 0.6
61
Si5338
Register 34.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
R3DIV_IN[2:0]
R3DIV[2:0]
MS3_PDN
DRV3_PDN
Type
R/W
R/W
R/W
R/W
Reset value = xxxx xxxx
Bit
7:5
62
Name
R3DIV_IN[2:0]
Function
Selects the input to the R3 divider. R3 divider output goes to CLK3.
0: P2DIV_IN (fbclk) selected
1: P1DIV_IN (refclk) selected
2: P2DIV_OUT (P2 divider output) selected
3: P1DIV_OUT (P1 divider output) selected
4: XOCLK selected
5: MultiSynth0 output selected
6: MultiSynth3 output selected
7: No Clock selected
4:2
R3DIV[2:0]
CLK3 R3 Output Divider.
0: Divide by 1
1: Divide by 2
2: Divide by 4
3: Divide by 8
4: Divide by 16
5: Divide by 32
1
MS3_PDN
MultiSynth3 Power Down.
0: MultiSynth3 is power up
1: MultiSynth3 powered down
0
DRV3_PDN
R3 and CLK3 Powerdown.
0: R3 output divider and CLK3 driver powered up
1: R3 output divider and CLK3 driver powered down
Rev. 0.6
Si5338
Register 35.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
DRV3_VDDO[1:0]
DRV2_VDDO[1:0]
DRV1_VDDO[1:0]
DRV0_VDDO[1:0]
Type
R/W
R/W
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
Function
7:6
VDDO Setting for CLK3.
0: VDDO3 = 3.3 V (not for HSTL)
DRV3_VDDO[1:0] 1: VDDO3 = 2.5 V (not for HSTL)
2: VDDO3 = 1.8 V (not for HSTL or LVPECL)
3: VDDO3 = 1.5 V (HSTL only)
5:4
VDDO Setting for CLK2.
0: VDDO2 = 3.3 V (not for HSTL)
DRV2_VDDO[1:0] 1: VDDO2 = 2.5 V (not for HSTL)
2: VDDO2 = 1.8 V (not for HSTL or LVPECL)
3: VDDO2 = 1.5 V (HSTL only)
3:2
VDDO Setting for CLK1.
0: VDDO1 = 3.3 V (not for HSTL)
DRV1_VDDO[1:0] 1: VDDO1 = 2.5 V (not for HSTL)
2: VDDO1 = 1.8 V (not for HSTL or LVPECL)
3: VDDO1 = 1.5 V (HSTL only)
1:0
VDDO Setting for CLK0.
0: VDDO0 = 3.3 V (not for HSTL)
DRV0_VDDO[1:0] 1: VDDO0 = 2.5 V (not for HSTL)
2: VDDO0 = 1.8 V (not for HSTL or LVPECL)
3: VDDO0 = 1.5 V (HSTL only)
Note: If the VDDOx voltage is below the minimum allowed voltage of the programmed voltage setting in Register 35, the
output driver may not turn on.
Rev. 0.6
63
Si5338
Register 36.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
DRV0_INV[1:0]
DRV0_FMT[2:0]
Type
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
7:5
Reserved
4:3
2:0
64
Function
Reserved.
DRV0_INV[1:0]
Invert Driver for CLK0 for CMOS/SSTL/HSTL Outputs.
0: Both outputs are in phase
1: CLK0A inverted
2: CLK0B inverted
3: CLK0A/B inverted and in phase
DRV0_FMT[2:0]
CLK0 Signal Format.
0: Reserved
1: CLK0A = (CMOS/SSTL/HSTL), CLK0B = off
2: CLK0B = (CMOS/SSTL/HSTL), CLK0A = off
3: CLK0A,B = (CMOS/SSTL/HSTL)
4: LVPECL
5: Reserved
6: LVDS
7: HCSL
Rev. 0.6
D0
Si5338
Register 37.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
DRV1_INV[1:0]
DRV1_FMT[2:0]
Type
R/W
R/W
D0
Reset value = xxxx xxxx
Bit
Name
7:5
Reserved
4:3
2:0
Function
Reserved.
DRV1_INV[1:0]
Invert Driver for CLK1 for CMOS/SSTL/HSTL Outputs.
0: Both outputs are in phase
1: CLK1A invert
2: CLK1B invert
3: CLK1A/B invert and in phase
DRV1_FMT[2:0]
CLK1 Signal Format.
0: Reserved
1: CLK1A = (CMOS/SSTL/HSTL), CLK1B = off
2: CLK1B = (CMOS/SSTL/HSTL), CLK1A = off
3: CLK1A,B = (CMOS/SSTL/HSTL)
4: LVPECL
5: Reserved
6: LVDS
7: HCSL
Rev. 0.6
65
Si5338
Register 38.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
DRV2_INV[1:0]
DRV2_FMT[2:0]
Type
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
7:5
Reserved
4:3
2:0
66
Function
Reserved.
DRV2_INV[1:0]
Invert Driver for CLK2 for CMOS/SSTL/HSTL Outputs.
0: Both outputs are in phase
1: CLK2A inverted
2: CLK2B inverted
3: CLK2A/B inverted and in phase
DRV2_FMT[2:0]
CLK2 Signal Format.
0: Reserved
1: CLK2A = (CMOS/SSTL/HSTL), CLK2B = off
2: CLK2B = (CMOS/SSTL/HSTL), CLK2A = off
3: CLK2A,B = (CMOS/SSTL/HSTL)
4: LVPECL
5: Reserved
6: LVDS
7: HCSL
Rev. 0.6
D0
Si5338
Register 39.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
DRV3_INV[1:0]
DRV3_FMT[2:0]
Type
R/W
R/W
D0
Reset value = xxxx xxxx
Bit
Name
7:5
Reserved
4:3
2:0
Function
Reserved.
DRV3_INV[1:0]
Invert Driver for CLK3 for CMOS/SSTL/HSTL Outputs.
0: Both outputs are in phase
1: CLK3A inverted
2: CLK3B inverted
3: CLK3A/B inverted and in phase
DRV3_FMT[2:0]
CLK3 Signal Format.
0: Reserved
1: CLK3A = (CMOS/SSTL/HSTL), CLK3B = off
2: CLK3B = (CMOS/SSTL/HSTL), CLK3A = off
3: CLK3A,B = (CMOS/SSTL/HSTL)
4: LVPECL
5: Reserved
6: LVDS
7: HCSL
Register 40.
Bit
D7
D6
D5
D4
D3
D2
Name
DRV1_TRIM [2:0]
DRV0_TRIM [4:0]
Type
R/W
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:5
DRV1_TRIM [2:0]
Trim Bits for CLK1 Driver.
Clockbuilder Desktop sets these values automatically. See AN411 for required
manual settings information
4:3
DRV0_TRIM [4:0]
Trim Bits for CLK0 Driver.
Clockbuilder Desktop sets these values automatically. See AN411 for required
manual settings information
Rev. 0.6
67
Si5338
Register 41.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
DRV2_TRIM [4:0]
DRV1_TRIM [4:3]
Type
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
Function
7
Reserved
6:2
DRV2_TRIM [4:0]
Trim Bits for CLK2 Driver.
Clockbuilder Desktop sets these values automatically. See AN411 for required
manual settings information.
1:0
DRV1_TRIM [4:3]
Trim Bits for CLK1 Driver.
Clockbuilder Desktop sets these values automatically. See AN411 for required
settings information.
Reserved.
Register 42.
Bit
D7
D6
D5
D4
D3
D2
Name
DRV3_TRIM [4:0]
Type
R/W
D1
D0
Reset value = xxxx xxxx
68
Bit
Name
Function
7:6
Reserved
Reserved.
5
Reserved
Must write 1b to this bit.
4:0
DRV3_TRIM [4:0]
Trim Bits for CLK3.
Clockbuilder Desktop sets these values automatically. See AN411 for required
manual settings information.
Rev. 0.6
Si5338
Register 45.
Bit
D7
D6
D5
D4
D3
Name
FCAL_OVRD[7:0]
Type
R/W
D2
D1
D0
D1
D0
D1
D0
Reset value = xxxx xxxx
Bit
7:0
Name
Function
FCAL_OVRD[7:0] Bits 7:0 of the Override Frequency Calibration for the VCO.
Register 46.
Bit
D7
D6
D5
D4
D3
Name
FCAL_OVRD[15:8]
Type
R/W
D2
Reset value = xxxx xxxx
Bit
7:0
Name
Function
FCAL_OVRD[15:8] Bits 15:8 of the Override Frequency Calibration for the VCO
Register 47.
Bit
D7
D6
D5
D4
D3
D2
Name
Reserved
FCAL_OVRD[17:16]
Type
R
R/W
Reset value = xxxx xxxx
Bit
Name
7:2
Reserved
1:0
Function
Reserved.
Must write 000101b to these bits if the device is not factory programmed.
FCAL_OVRD[17:16] Bits 17:16 of the Override Frequency Calibration for the VCO.
Rev. 0.6
69
Si5338
Register 48.
Bit
D7
D6
D5
D4
D3
D2
Name
PFD_EXTFB
PLL_KPHI[6:0]
Type
R/W
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7
PFD_EXTFB
Selects PFD feedback input from internal (see Register 30[7:5]) or external source.
0: Internal feedback path
1: External feedback path (zero delay mode)
6:0
PLL_KPHI[6:0]
Sets the charge pump current for the PFD. Clockbuilder Desktop sets these values
automatically. See AN411 for manual setting.
Register 49.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
FCAL_OVRD_EN
VCO_GAIN[2:0]
RSEL[1:0]
BWSEL[1:0]
Type
R/W
R/W
R/W
R/W
Reset value = xxxx xxxx
Bit
7
70
Name
Function
FCAL Override Enable.
FCAL_OVRD_EN 0: Do not use FCAL value in registers 45,46,47
1: Use FCAL value in registers 45,46,47
6:4
VCO_GAIN[2:0]
Sets the VCO Gain.
Clockbuilder Desktop sets these values automatically. See AN411 for manual setting.
3:2
RSEL[1:0]
Loop Filter Resistor Select.
Clockbuilder Desktop sets these values automatically. See AN411 for manual setting.
1:0
BWSEL[1:0]
Select the PLL Loopfilter.
Clockbuilder Desktop sets these values automatically. See AN411 for manual setting.
Rev. 0.6
Si5338
Register 50.
Bit
Name
D7
D6
D5
D4
PLL_ENABLE[1:0]
D3
D2
D1
D0
MSCAL[5:0]
Type
R/W
Reset value = xxxx xxxx
Bit
7:6
5:0
Name
Function
00: Disable PLL
11: Enable PLL
PLL_ENABLE[1:0]
It is expected that all Si5338 applications will need to have the PLL enabled; however, the PLL may be disabled when the Si5338 is set up in buffer mode.
MSCAL[5:0]
MultiSynth Calibration Value for Optimum Performance.
Clockbuilder Desktop sets these values automatically. See AN411 for manual setting.
Rev. 0.6
71
Si5338
Register 51.
Bit
D7
D6
D5
D4
Name
MS3_HS
MS2_HS
MS1_HS
MS0_HS
Type
R/W
R/W
R/W
R/W
D3
D2
D1
D0
MS_PEC[2:0]
Reset value = xxxx x111
Bit
Name
Function
MS3_HS
MultiSynth3 High Speed Mode.
When this bit is asserted, MultiSynth3 will only accept divide ratios of 4.0 or 6.0. Increment/decrement, SSC, and all phase functions are not available when this bit is set.
0: MultiSynth3 implements fractional divide ratios between 8 and 1023
1: MultiSynth3 can only implement 4.0 or 6.0 divide ratio.
MS2_HS
MultiSynth2 High Speed Mode.
When this bit is asserted, MultiSynth2 will only accept divide ratios of 4.0 or 6.0. Increment/decrement, SSC, and all phase functions are not available when this bit is set.
0: MultiSynth2 implements fractional divide ratios between 8 and 1023.
1: MultiSynth2 can only implement 4.0 or 6.0 divide ratio.
MS1_HS
MultiSynth1 High Speed Mode.
When this bit is asserted, MultiSynth1 will only accept divide ratios of 4.0 or 6.0. Increment/decrement, SSC, and all phase functions are not available when this bit is set.
0: MultiSynth1 implements fractional divide ratios between 8 and 1023.
1: MultiSynth1 can only implement 4.0 or 6.0 divide ratio.
4
MS0_HS
MultiSynth0 High Speed Mode.
When this bit is asserted, MultiSynth0 will only accept divide ratios of 4.0 or 6.0. Increment/decrement, SSC, and all phase functions are not available when this bit is set.
0: MultiSynth0 implements fractional divide ratios between 8 and 1023.
1: MultiSynth0 can only implement 4.0 or 6.0 divide ratio.
3
Unused
Unused.
2:0
MS_PEC[2:0]
7
6
5
72
MultiSynth Phase Error Correction.
All non-factory programmed devices must have 111b written to these bits.
Rev. 0.6
Si5338
Register 52.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
MS0_FIDCT[1:0]
MS0_FIDDIS
MS0_SSMODE[1:0]
MS0_PHIDCT[1:0]
Type
R/W
R/W
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
7
Reserved
6:5
4
3:2
1:0
Function
Reserved.
MS0_FIDCT[1:0]
MultiSynth0 Frequency Increment/Decrement Control.
Bit 4 (disable) must be 0 before writing an increment or decrement
to these bits. Only MS0 can have pin control of Frequency Increment/Decrement.
0: No frequency inc/dec on MS0
1: Enable pin control of frequency inc/dec
2: Frequency increment on MS0, self-clearing
3: Frequency decrement on MS0, self-clearing
MS0_FIDDIS
MultiSynth0 Frequency Increment/Decrement Disable (see also
Register 242[1]).
0: Frequency inc/dec enabled on MS0
1: Frequency inc/dec disabled on MS0
MS0_SSMODE[1:0]
MS0_PHIDCT[1:0]
MultiSynth0 Spread Spectrum Mode Select.
0: No SSC on MS0
1: Center spread on MS0
2: Reserved
3: Down spread MS0
MultiSynth0 Phase Increment/Decrement Control.
0: No phase inc/dec on MS0
1: Enable pin control of phase inc/dec
2: Phase increment on MS0, self clearing
3: Phase decrement on MS0, self clearing
Rev. 0.6
73
Si5338
Register 53.
Bit
D7
D6
D5
D4
D3
Name
MS0_P1[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS0_P1[7:0]
MultiSynth0 Parameter 1.
This 18-bit number is an encoded representation of the integer part of the
MultiSynth0 divider.
Register 54.
Bit
D7
D6
D5
D4
D3
Name
MS0_P1[15:8]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
74
Bit
Name
15:8
MS0_P1[15:8]
Function
MultiSynth0 Parameter 1.
This 18-bit number is an encoded representation of the integer part of the
MultiSynth0 divider.
Rev. 0.6
Si5338
Register 55.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
MS0_P2[5:0]
MS0_P1[17:16]
Type
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
Function
7:2
MS0_P2[5:0]
1:0
MS0_P1[17:16]
MultiSynth0 Parameter 2.
This 30-bit number is an encoded representation of the numerator for the fractional part of the MultiSynth0 Divider.
MultiSynth0 Parameter 1.
This 18-bit number is an encoded representation of the integer part of the
MultiSynth0 divider.
Register 56.
Bit
D7
D6
D5
D4
D3
Name
MS0_P2[13:6]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_P2[13:6]
Function
MultiSynth0 Parameter 2.
This 30-bit number is an encoded representation of the numerator for the fractional part of the MultiSynth0 Divider.
Rev. 0.6
75
Si5338
Register 57.
Bit
D7
D6
D5
D4
D3
D2
Name
MS0_P2[21:14]
Type
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS0_P2[21:14]
MultiSynth0 Parameter 2.
This 30-bit number is an encoded representation of the numerator for the fractional part of the MultiSynth0 Divider.
Register 58.
Bit
D7
D6
D5
D4
D3
Name
MS0_P2[29:22]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
76
Bit
Name
7:0
MS0_P2[29:22]
Function
MultiSynth0 Parameter 2.
This 30-bit number is an encoded representation of the numerator for the
fractional part of the MultiSynth0 Divider.
Rev. 0.6
Si5338
Register 59.
Bit
D7
D6
D5
D4
D3
Name
MS0_P3[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_P3[7:0]
Function
MultiSynth0 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth0 divider.
Register 60.
Bit
D7
D6
D5
D4
D3
Name
MS0_P3[15:8]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS0_P3[15:8]
MultiSynth0 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth0 divider.
Register 61.
Bit
D7
D6
D5
D4
D3
Name
MS0_P3[23:16]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_P3[23:16]
Function
MultiSynth0 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth0 divider.
Rev. 0.6
77
Si5338
Register 62.
Bit
D7
D6
D5
D4
D3
D2
Name
MS0_P3[29:24]
Type
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:6
Reserved
5:0
78
MS0_P3[29:24]
Function
Reserved.
MultiSynth0 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth0 divider.
Rev. 0.6
Si5338
Register 63.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
MS1_FIDCT[1:0]
MS1_FIDDIS
MS1_SSMODE[1:0]
MS1_PHIDCT[1:0]
Type
R/W
R/W
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
7
Reserved
6:5
4
3:2
1:0
MS1_FIDCT[1:0]
MS1_FIDDIS
MS1_SSMODE[1:0]
MS1_PHIDCT[1:0]
Function
Reserved.
MultiSynth1 Frequency Increment/Decrement Control.
Bit 4 (disable) must be 0 before writing an increment or decrement
to these bits.
0: No frequency inc/dec on MS1
1: Reserved
2: Frequency increment on MS1, self-clearing
3: Frequency decrement on MS1, self-clearing
MultiSynth1 Frequency Increment/Decrement Disable.
See also Register 242[1].
0: Frequency inc/dec enabled on MS1
1: Frequency inc/dec disabled on MS1
MultiSynth1 Spread Spectrum Mode Select.
0: No SSC on MS1
1: Center spread on MS1
2: Reserved
3: Downspread MS1
MultiSynth1 Phase Increment/Decrement Control.
Writing a 10 or 11 will self clear back to 0.
0: No phase inc/dec on MS1
1: Enable pin control of phase inc/dec
2: Phase increment on MS1, self clearing
3: Phase decrement on MS1, self clearing
Rev. 0.6
79
Si5338
Register 64.
Bit
D7
D6
D5
D4
D3
Name
MS1_P1[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS1_P1[7:0]
MultiSynth1 Parameter 1.
This 18-bit number is an encoded representation of the integer part of the
MultiSynth1 divider.
Register 65.
Bit
D7
D6
D5
D4
D3
Name
MS1_P1[15:8]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
80
Bit
Name
7:0
MS1_P1[15:8]
Function
MultiSynth1 Parameter 1.
This 18-bit number is an encoded representation of the integer part of the
MultiSynth1 divider.
Rev. 0.6
Si5338
Register 66.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
MS1_P2[5:0]
MS1_P1[17:16]
Type
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
Function
7:2
MS1_P2[5:0]
MultiSynth1 Parameter 2.
This 30-bit number is an encoded representation of the numerator for the fractional part of the MultiSynth1 Divider.
1:0
MS1_P1[17:16]
MultiSynth1 Parameter 1.
This 18-bit number is an encoded representation of the integer part of the
MultiSynth1 divider.
Register 67.
Bit
D7
D6
D5
D4
D3
Name
MS1_P2[13:6]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS1_P2[13:6]
MultiSynth1 Parameter 2.
This 30-bit number is an encoded representation of the numerator for the fractional
part of the MultiSynth1 Divider.
Rev. 0.6
81
Si5338
Register 68.
Bit
D7
D6
D5
D4
D3
Name
MS1_P2[21:14]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS1_P2[21:14]
MultiSynth1 Parameter 2.
This 30-bit number is an encoded representation of the numerator for the fractional part of the MultiSynth1 Divider.
Register 69.
Bit
D7
D6
D5
D4
D3
Name
MS1_P2[29:22]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS1_P2[29:22]
MultiSynth1 Parameter 2.
This 30-bit number is an encoded representation of the numerator for the fractional part of the MultiSynth1 Divider.
Register 70.
Bit
D7
D6
D5
D4
D3
Name
MS1_P3[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
82
Bit
Name
Function
7:0
MS1_P3[7:0]
MultiSynth1 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional
part of the MultiSynth1 Divider.
Rev. 0.6
Si5338
Register 71.
Bit
D7
D6
D5
D4
D3
Name
MS1_P3[15:8]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS1_P3[15:8]
MultiSynth1 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth1 Divider.
Register 72.
Bit
D7
D6
D5
D4
D3
Name
MS1_P3[23:16]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS1_P3[23:16]
MultiSynth1 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth1 Divider.
Register 73.
Bit
D7
D6
D5
D4
D3
D2
Name
MS1_P3[29:24]
Type
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:6
Reserved
5:0
MS1_P3[29:24]
Function
Reserved
MultiSynth1 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth1 Divider.
Rev. 0.6
83
Si5338
Register 74.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
MS2_FIDCT[1:0]
MS2_FIDDIS
MS2_SSMODE[1:0]
MS2_PHIDCT[1:0]
Type
R/W
R/W
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
7
Reserved
6:5
4
3:2
1:0
84
Function
Reserved.
MS2_FIDCT[1:0]
MultiSynth2 Frequency Increment/Decrement Control.
Bit 4 (disable) must be 0 before writing an increment or decrement
to these bits.
0: No frequency inc/dec on MS2
1: Reserved
2: Frequency increment on MS2, self-clearing
3: Frequency decrement on MS2, self-clearing
MS2_FIDDIS
MultiSynth2 Frequency Increment/Decrement Disable (see also
Register 242[1]).
0: Frequency inc/dec enabled on MS2
1: Frequency inc/dec disabled on MS2
MS2_SSMODE[1:0]
MS2_PHIDCT[1:0]
MultiSynth2 Spread Spectrum Mode Select.
0: No SSC on MS2
1: Center spread on MS2
2: Reserved
3: Down spread MS2
MultiSynth2 Phase Increment/Decrement Control.
0: No phase inc/dec on MS2
1: Enable pin control of phase inc/dec
2: Phase increment on MS2, self clearing
3: Phase decrement on MS2, self clearing
Rev. 0.6
Si5338
Register 75.
Bit
D7
D6
D5
D4
D3
Name
MS2_P1[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS2_P1[7:0]
MultiSynth2 Parameter 1.
This 18-bit number is an encoded representation of the integer part of the
MultiSynth2 divider.
Register 76.
Bit
D7
D6
D5
D4
D3
Name
MS2_P1[15:8]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS2_P1[15:8]
Function
MultiSynth2 Parameter 1.
This 18-bit number is an encoded representation of the integer part of the
MultiSynth2 divider.
Rev. 0.6
85
Si5338
Register 77.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
MS2_P2[5:0]
MS2_P1[17:16]
Type
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
Function
7:2
MS2_P2[5:0]
MultiSynth2 Parameter 2.
This 30-bit number is an encoded representation of the numerator for the fractional part of the MultiSynth2 Divider.
1:0
MS2_P1[17:16]
MultiSynth2 Parameter 1.
This 18-bit number is an encoded representation of the integer part of the
MultiSynth2 divider.
Register 78.
Bit
D7
D6
D5
D4
D3
Name
MS2_P2[13:6]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
86
Bit
Name
Function
7:0
MS2_P2[13:6]
MultiSynth2 Parameter 2.
This 30-bit number is an encoded representation of the numerator for the fractional
part of the MultiSynth2 Divider.
Rev. 0.6
Si5338
Register 79.
Bit
D7
D6
D5
D4
D3
Name
MS2_P2[21:14]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS2_P2[21:14]
MultiSynth2 Parameter 2.
This 30-bit number is an encoded representation of the numerator for the fractional part of the MultiSynth2 Divider.
Register 80.
Bit
D7
D6
D5
D4
D3
Name
MS2_P2[29:22]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS2_P2[29:22]
Function
MultiSynth2 Parameter 2.
This 30-bit number is an encoded representation of the numerator for the fractional part of the MultiSynth2 Divider.
Rev. 0.6
87
Si5338
Register 81.
Bit
D7
D6
D5
D4
D3
Name
MS2_P3[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
MS2_P3[7:0]
MultiSynth2 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional
part of the MultiSynth2 Divider.
Register 82.
Bit
D7
D6
D5
D4
D3
Name
MS2_P3[15:8]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
88
Bit
Name
7:0
MS2_P3[15:8]
Function
MultiSynth2 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth2 Divider.
Rev. 0.6
Si5338
Register 83.
Bit
D7
D6
D5
D4
D3
Name
MS2_P3[23:16]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS2_P3[23:16]
MultiSynth2 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth2 Divider.
Register 84.
Bit
D7
D6
D5
D4
D3
D2
Name
MS2_P3[29:24]
Type
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:6
Reserved
MS2_P3[29:24]
Function
Reserved.
MultiSynth2 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth2 Divider.
Rev. 0.6
89
Si5338
Register 85.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
MS3_FIDCT[1:0]
MS3_FIDDIS
MS3_SSMODE[1:0]
MS3_PHIDCT[1:0]
Type
R/W
R/W
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
7
Reserved
6:5
4
3:2
1:0
90
MS3_FIDCT[1:0]
MS3_FIDDIS
MS3_SSMODE[1:0]
MS3_PHIDCT[1:0]
Function
Reserved.
MultiSynth3 Frequency Increment/Decrement Control.
Bit 4 (disable) must be 3 before writing an increment or decrement to these
bits.
0: No frequency inc/dec on MS3
1: Reserved
2: Frequency increment on MS3, self-clearing
3: Frequency decrement on MS3, self-clearing
MultiSynth3 Frequency Increment/Decrement Disable (see also
Register 242[1]).
0: Frequency inc/dec enabled on MS3
1: Frequency inc/dec disabled on MS3
MultiSynth3 Spread Spectrum Mode Select.
0: No SSC on MS3
1: Center spread on MS3
2: Reserved
3: Down spread MS3
MultiSynth3 Phase Increment/Decrement Control.
0: No phase inc/dec on MS3
1: Enable pin control of phase inc/dec
2: Phase increment on MS3
3: Phase decrement on MS3
Rev. 0.6
Si5338
Register 86.
Bit
D7
D6
D5
D4
D3
Name
MS3_P1[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS3_P1[7:0]
MultiSynth3 Parameter 1.
This 18-bit number is an encoded representation of the integer part of the
MultiSynth3 divider.
Register 87.
Bit
D7
D6
D5
D4
D3
Name
MS3_P1[15:8]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS3_P1[15:8]
Function
MultiSynth3 Parameter 1.
This 18-bit number is an encoded representation of the integer part of the
MultiSynth3 divider
Rev. 0.6
91
Si5338
Register 88.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
MS3_P2[5:0]
MS3_P1[17:16]
Type
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
Function
7:2
MS3_P2[5:0]
1:0
MS3_P1[17:16]
MultiSynth3 Parameter 2.
This 30-bit number is an encoded representation of the denominator for the
fractional part of the MultiSynth3 Divider.
MultiSynth3 Parameter 1.
This 18-bit number is an encoded representation of the integer part of the
MultiSynth3 divider.
Register 89.
Bit
D7
D6
D5
D4
D3
Name
MS3_P2[13:6]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
92
Bit
Name
7:0
MS3_P2[13:6]
Function
MultiSynth3 Parameter 2.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth3 Divider.
Rev. 0.6
Si5338
Register 90.
Bit
D7
D6
D5
D4
D3
Name
MS3_P2[21:14]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS3_P2[21:14]
MultiSynth3 Parameter 2.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth3 Divider.
Register 91.
Bit
D7
D6
D5
D4
D3
Name
MS3_P2[29:22]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS3_P2[29:22]
MultiSynth3 Parameter 2.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth3 Divider.
Register 92.
Bit
D7
D6
D5
D4
D3
Name
MS3_P3[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS3_P3[7:0]
MultiSynth3 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional
part of the MultiSynth3 Divider.
Rev. 0.6
93
Si5338
Register 93.
Bit
D7
D6
D5
D4
D3
Name
MS3_P3[15:8]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS3_P3[15:8]
MultiSynth3 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth3 Divider
Register 94.
Bit
D7
D6
D5
D4
D3
Name
MS3_P3[23:16]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS3_P3[23:16]
MultiSynth3 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth3 Divider
Register 95.
Bit
D7
D6
D5
D4
D3
D2
Name
MS3_P3[29:24]
Type
R/W
D1
D0
Reset value = xxxx xxxx
94
Bit
Name
7:6
Reserved
5:0
MS3_P3[29:24]
Function
Reserved.
MultiSynth3 Parameter 3.
This 30-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth3 Divider.
Rev. 0.6
Si5338
Register 97.
Bit
D7
D6
D5
D4
D3
Name
MSN_P1[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MSN_P1[7:0]
Feedback MultiSynthN Parameter 1.
This 18-bit number is an encoded representation of the integer part of the MultiSynth
Feedback divider.
Register 98.
Bit
D7
D6
D5
D4
D3
Name
MSN_P1[15:8]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MSN_P1[15:8]
Feedback MultiSynthN Parameter 1.
This 18-bit number is an encoded representation of the integer part of the MultiSynth
Feedback divider.
Rev. 0.6
95
Si5338
Register 99.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
MSN_P2[5:0]
MSN_P1[17:16]
Type
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
Function
7:2
MSN_P2[5:0]
Feedback MultiSynthN Parameter 2.
This 18-bit number is an encoded representation of the numerator for the fractional part of the MultiSynth Feedback divider.
1:0
MSN_P1[17:16]
Feedback MultiSynthN Parameter 1.
This 18-bit number is an encoded representation of the integer part of the MultiSynth Feedback divider.
Register 100.
Bit
D7
D6
D5
D4
D3
Name
MSN_P2[13:6]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
96
Bit
Name
7:0
MSN_P2[13:6]
Function
Feedback MultiSynthN Parameter 2.
This 18-bit number is an encoded representation of the numerator for the fractional
part of the MultiSynth Feedback divider.
Rev. 0.6
Si5338
Register 101.
Bit
D7
D6
D5
D4
D3
Name
MSN_P2[21:14]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MSN_P2[21:14]
Feedback MultiSynthN Parameter 2.
This 18-bit number is an encoded representation of the numerator for the fractional
part of the MultiSynth Feedback divider.
Register 102.
Bit
D7
D6
D5
D4
D3
Name
MSN_P2[29:22]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MSN_P2[29:22]
Feedback MultiSynthN Parameter 2.
This 18-bit number is an encoded representation of the numerator for the fractional part of the MultiSynth Feedback divider.
Register 103.
Bit
D7
D6
D5
D4
D3
Name
MSN_P3[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MSN_P3[7:0]
Feedback MultiSynthN Parameter 3.
This 18-bit number is an encoded representation of the denominator for the fractional
part of the MultiSynth Feedback divider.
Rev. 0.6
97
Si5338
Register 104.
Bit
D7
D6
D5
D4
D3
Name
MSN_P3[15:8]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MSN_P3[15:8]
Feedback MultiSynthN Parameter 3.
This 18-bit number is an encoded representation of the denominator for the fractional
part of the MultiSynth Feedback divider
Register 105.
Bit
D7
D6
D5
D4
D3
Name
MSN_P3[23:16]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
98
Bit
Name
7:0
MSN_P3[23:16]
Function
Feedback MultiSynthN Parameter 3.
This 18-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth Feedback divider.
Rev. 0.6
Si5338
Register 106.
Bit
D7
D6
D5
D4
D3
D2
Name
NOTERM_FB
MSN_P3[29:24]
Type
R/W
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7
Reserved
Reserved.
Must write 1b to this bit.
6
Reserved
Reserved.
5:0
MSN_P3[29:24]
Feedback MultiSynthN Parameter 3.
This 18-bit number is an encoded representation of the denominator for the fractional part of the MultiSynth Feedback divider.
Register 107.
Bit
D7
D6
D5
D4
D3
Name
MS0_PHOFF[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
7:0
Name
Function
MS0_PHOFF[7:0]
MultiSynth0 Initial Phase Offset.
MultiSynth0_PHOFF[14:0] is a 2s complement number. The initial phase
offset is MultiSynth0_PHOFF[14:0]*Tvco/128 where Tvco is the period of
the VCO.
Rev. 0.6
99
Si5338
Register 108.
Bit
D7
D6
D5
D4
D3
D2
Name
MS0_PHOFF[14:8]
Type
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
7
Reserved
6:0
Function
Reserved.
MultiSynth0 Initial Phase Offset.
MultiSynth0_PHOFF[14:0] is a 2s complement number. The initial
phase offset is MultiSynth0_PHOFF[14:0]*Tvco/128 where Tvco is the
period of the VCO.
MS0_PHOFF[14:8]
Register 109.
Bit
D7
D6
D5
D4
D3
Name
MS0_PHSTEP[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
7:0
100
Name
MS0_PHSTEP[7:0]
Function
MultiSynth0 Phase Step Size.
The phase step size is MultiSynth0_PHSTEP[13:0]*Tvco/128 where
Tvco is the period of the VCO. Either the phase inc/dec pins (if available) or register 52[1:0] will control the stepping of phase. A phase
increment will delay the clock edge.
Rev. 0.6
Si5338
Register 110.
Bit
D7
D6
D5
D4
D3
D2
Name
CLK0_DISST[1:0]
MS0_PHSTEP[13:8]
Type
R/W
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:6
Function
CLK0 Output Driver State When Disabled.
00: High impedance
01: Logic low
10: Logic high
11: Always on even if disabled
CLK0_DISST[1:0
5:0
MS0 Phase Step Size.
The phase step size is MS0_PHSTEP[13:0]*Tvco/128 where Tvco is
the period of the VCO. Either the phase inc/dec pins (if available) or
register 52[1:0] will control the stepping of phase. A phase increment
will delay the clock edge.
MS0_PHSTEP[13:8]
Register 111.
Bit
D7
D6
D5
D4
D3
Name
MS1_PHOFF[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
7:0
Name
Function
MS1_PHOFF[7:0]
MultiSynth1 Initial Phase Offset.
MultiSynth1_PHOFF[14:0] is a 2s complement number. The initial phase
offset is MultiSynth1_PHOFF[14:0]*Tvco/128 where Tvco is the period of
the VCO.
Rev. 0.6
101
Si5338
Register 112.
Bit
D7
D6
D5
D4
D3
D2
Name
MS1_PHOFF[14:8]
Type
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
7
Reserved
6:0
MS1_PHOFF[14:8]
Function
Reserved
MultiSynth1 Initial Phase Offset.
MultiSynth1_PHOFF[14:0] is a 2s complement number. The initial
phase offset is MultiSynth1_PHOFF[14:0] x Tvco/128 where Tvco is the
period of the VCO.
Register 113.
Bit
D7
D6
D5
D4
D3
Name
MS1_PHSTEP[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
7:0
102
Name
Function
MS1_PHSTEP[7:0]
MultiSynth1 Phase Step Size.
The phase step size is MultiSynth1_PHSTEP[13:0] x Tvco/128 where
Tvco is the period of the VCO. Either the phase inc/dec pins (if available) or register 63[1:0] will control the stepping of phase. A phase
increment will delay the clock edge.
Rev. 0.6
Si5338
Register 114.
Bit
D7
D6
D5
D4
D3
D2
Name
CLK1_DISST[1:0]
MS1_PHSTEP[13:8]
Type
R/W
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:6
Function
MultiSynth1 Output Driver State When Disabled.
00: High impedance
01: Logic low
10: Logic high
11: Always on even if disabled
CLK1_DISST[1:0]
5:0
MultiSynth1 Phase Step Size.
The phase step size is MS1_PHSTEP[13:0]*Tvco/128 where Tvco is
the period of the VCO. Either the phase inc/dec pins (if available) or
register 63[1:0] will control the stepping of phase. A phase increment
will delay the clock edge.
MS1_PHSTEP[13:8]
Register 115.
Bit
D7
D6
D5
D4
D3
Name
MS2_PHOFF[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
7:0
Name
Function
MS2_PHOFF[7:0]
MultiSynth2 Initial Phase Offset.
MultiSynth2_PHOFF[14:0] is a 2s complement number. The initial phase
offset is MultiSynth2_PHOFF[14:0] x Tvco/128 where Tvco is the period
of the VCO.
Rev. 0.6
103
Si5338
Register 116.
Bit
D7
D6
D5
D4
Name
D3
D2
D1
D0
MS2_PHOFF[14:8]
Type
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
7
Reserved
6:0
Function
Reserved.
Must write 1b to this bit.
MultiSynth2 Initial Phase Offset.
MultiSynth2_PHOFF[14:0] is a 2s complement number. The initial
phase offset is MultiSynth2_PHOFF[14:0] x Tvco/128 where Tvco is
the period of the VCO.
MS2_PHOFF[14:8]
Register 117.
Bit
D7
D6
D5
D4
D3
Name
MS2_PHSTEP[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
7:0
104
Name
Function
MS2_PHSTEP[7:0]
MultiSynth2 Phase Step Size.
The phase step size is MultiSynth2_PHSTEP[13:0] x Tvco/128 where
Tvco is the period of the VCO. Either the phase inc/dec pins (if available) or register 74[1:0] will control the stepping of phase. A phase
increment will delay the clock edge.
Rev. 0.6
Si5338
Register 118.
Bit
D7
D6
D5
D4
D3
D2
Name
CLK2_DISST[1:0]
MS2_PHSTEP[13:8]
Type
R/W
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:6
Function
MultiSynth2 Output Driver State When Disabled.
00: High impedance
01: Logic low
10: Logic high
11: Always on even if disabled
CLK2_DISST[1:0]
5:0
MultiSynth2 Phase Step Size.
The phase step size is MS2_PHSTEP[13:0]*Tvco/128 where Tvco is
the period of the VCO. Either the phase inc/dec pins (if available) or
register 74[1:0] will control the stepping of phase. A phase increment
will delay the clock edge.
MS2_PHSTEP[13:8]
Register 119.
Bit
D7
D6
D5
D4
D3
Name
MS3_PHOFF[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
7:0
Name
Function
MS3_PHOFF[7:0]
MultiSynth3 Initial Phase Offset.
MultiSynth3_PHOFF[14:0] is a 2s complement number. The initial phase
offset is MultiSynth3_PHOFF[14:0] x Tvco/128 where Tvco is the period
of the VCO.
Rev. 0.6
105
Si5338
Register 120.
Bit
D7
D6
D5
D4
D3
D2
Name
MS3_PHOFF[14:8]
Type
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
7
Unused
6:0
MS3_PHOFF[14:8]
Function
Unused.
MultiSynth3 Initial Phase Offset.
MultiSynth3_PHOFF[14:0] is a 2s complement number. The initial
phase offset is MultiSynth3_PHOFF[14:0] x Tvco/128 where Tvco is the
period of the VCO.
Register 121.
Bit
D7
D6
D5
D4
D3
Name
MS3_PHSTEP[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
7:0
106
Name
MS3_PHSTEP[7:0]
Function
MultiSynth3 Phase Step Size.
The phase step size is MultiSynth3_PHSTEP[13:0] x Tvco/128 where
Tvco is the period of the VCO. Either the phase inc/dec pins (if available) or register 85[1:0] will control the stepping of phase. A phase
increment will delay the clock edge.
Rev. 0.6
Si5338
Register 122.
Bit
D7
D6
D5
D4
D3
D2
Name
CLK3_DISST[1:0]
MS3_PHSTEP[13:8]
Type
R/W
R/W
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:6
Function
MultiSynth3 Output Driver State When Disabled.
00: High impedance
01: Logic low
10: Logic high
11: Always on even if disabled
CLK3_DISST[1:0]
5:0
MultiSynth3 Phase Step Size.
The phase step size is MultiSynth3_PHSTEP[13:0] x Tvco/128 where
Tvco is the period of the VCO. Either the phase inc/dec pins (if available) or register 85[1:0] will control the stepping of phase. A phase
increment will delay the clock edge.
MS3_PHSTEP[13:8]
Register 123.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP1[7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP1[7:0]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 1.
Rev. 0.6
107
Si5338
Register 124.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP1 [15:8]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP1 [15:8]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 1.
Register 125.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP1 [23:16]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP1 [23:16]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 1.
Register 126.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP1 [31:24]
Type
R/W
D2
D1
Reset value = xxxx xxxx
108
Bit
Name
7:0
MS0_FIDP1 [31:24]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 1.
Rev. 0.6
D0
Si5338
Register 127.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP1 [39:32]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP1 [39:32]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 1.
Register 128.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP1 [47:40]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP1 [47:40]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 1.
Register 129.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
MS0_FIDP1 [51:48]
Type
R/W
D0
Reset value = 001x xxxx
Bit
Name
7:4
Reserved
3:0
MS0_FIDP1[51:48]
Function
Reserved.
MultiSynth0 Frequency Increment/Decrement Parameter 1.
Rev. 0.6
109
Si5338
Register 130.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
MS0_FIDP2 [51:48]
Type
R/W
D0
Reset value = xxxx xxxx
Bit
Name
7:4
Reserved
3:0
MS0_FIDP2[51:48]
Function
Reserved
MultiSynth0 Frequency Increment/Decrement Parameter 2.
Register 131.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP2 [47:40]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP2 [47:40]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 2.
Register 132.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP2 [39:32]
Type
R/W
D2
D1
Reset value = xxxx xxxx
110
Bit
Name
7:0
MS0_FIDP2 [39:32]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 2.
Rev. 0.6
D0
Si5338
Register 133.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP2 [31:24]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP2 [31:24]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 2.
Register 134.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP2 [23:16]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP2 [23:16]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 2.
Register 135.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP2 [15:8]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP2 [15:8]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 2.
Rev. 0.6
111
Si5338
Register 136.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP2 [7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP2 [7:0]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 2.
Register 137.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP3 [7:0]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP3 [7:0]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 3.
Register 138.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP3 [15:8]
Type
R/W
D2
D1
Reset value = xxxx xxxx
112
Bit
Name
7:0
MS0_FIDP3 [15:8]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 3.
Rev. 0.6
D0
Si5338
Register 139.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP3 [23:16]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP3 [23:16]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 3.
Register 140.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP3 [31:24]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP3 [31:24]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 3.
Register 141.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP3 [39:32]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
7:0
MS0_FIDP3 [39:32]
Function
MultiSynth0 Frequency Increment/Decrement Parameter 3.
Rev. 0.6
113
Si5338
Register 142.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP3 [47:40]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS0_FIDP3 [47:40]
MultiSynth0 Frequency Increment/Decrement Parameter 3.
Register 143.
Bit
D7
D6
D5
D4
D3
Name
MS0_FIDP3 [55:48]
Type
R/W
D2
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
MS0_FIDP3 [55:48]
MultiSynth0 Frequency Increment/Decrement Parameter 3.
Register 144.
Bit
D7
D6
Name
MS0_ALL
Type
R/W
D5
D4
D3
D2
D1
D0
MS0_FIDP3[62:56]
Reset value = xxxx xxxx
Bit
Name
7
MS0_ALL
6:0
114
Function
Use MultiSynth0 for All Outputs.
If set, the MultiSynth0 output is routed to the mux at the input of each R divider.
Unused MultiSynths should be powered down to save power.
MS0_FIDP3[62:56] MultiSynth0 Frequency Increment/Decrement Parameter 3.
Rev. 0.6
Si5338
Register 152.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP1[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP1[7:0]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 1.
Register 153.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP1[15:8]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP1[15:8]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 1.
Register 154.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP1[23:16]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP1[23:16]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 1.
Rev. 0.6
115
Si5338
Register 155.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP1[31:24]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP1[31:24]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 1.
Register 156.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP1[39:32]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP1[39:32]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 1.
Register 157.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP1[47:40]
Type
R/W
D2
D1
Reset value = 0000 0000
116
Bit
Name
7:0
MS1_FIDP1[47:40]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 1.
Rev. 0.6
D0
Si5338
Register 158.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
MS1_FIDP1[51:48]
Type
R/W
D0
Reset value = 0000 0000
Bit
Name
7:4
Reserved
3:0
MS1_FIDP1[51:48]
Function
Reserved.
MultiSynth1 Frequency Increment/Decrement Parameter 1.
Register 159.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
MS1_FIDP2[51:48]
Type
R/W
D0
Reset value = 0000 0000
Bit
Name
7:4
Reserved
3:0
MS1_FIDP2[51:48]
Function
Reserved
MultiSynth1 Frequency Increment/Decrement Parameter 2.
Register 160.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP2[47:40]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP2[47:40]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 2.
Rev. 0.6
117
Si5338
Register 161.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP2[39:32]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP2[39:32]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 2.
Register 162.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP2[31:24]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP2[31:24]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 2.
Register 163.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP2[23:16]
Type
R/W
D2
D1
Reset value = 0000 0000
118
Bit
Name
7:0
MS1_FIDP2[23:16]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 2.
Rev. 0.6
D0
Si5338
Register 164.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP2[15:8]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP2[15:8]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 2.
Register 165.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP2[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP2[7:0]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 2.
Register 166.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP3[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP3[7:0]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 3.
Rev. 0.6
119
Si5338
Register 167.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP3[15:8]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP3[15:8]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 3.
Register 168.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP3[23:16]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP3[23:16]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 3.
Register 169.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP3[31:24]
Type
R/W
D2
D1
Reset value = 0000 0000
120
Bit
Name
7:0
MS1_FIDP3[31:24]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 3.
Rev. 0.6
D0
Si5338
Register 170.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP3[39:32]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP3[39:32]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 3.
Register 171.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP3[47:40]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP3[47:40]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 3.
Register 172.
Bit
D7
D6
D5
D4
D3
Name
MS1_FIDP3[55:48]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_FIDP3[55:48]
Function
MultiSynth1 Frequency Increment/Decrement Parameter 3.
Rev. 0.6
121
Si5338
Register 173.
Bit
D7
D6
D5
D4
D3
D2
Name
MS1_FIDP3[62:56]
Type
R/W
D1
D0
Reset value = 0000 0000
Bit
Name
7
Unused
6:0
MS1_FIDP3[62:56]
Function
Unused.
MultiSynth1 Frequency Increment/Decrement Parameter 3.
Register 174.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP1[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP1[7:0]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 1.
Register 175.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP1[15:8]
Type
R/W
D2
D1
Reset value = 0000 0000
122
Bit
Name
7:0
MS2_FIDP1[15:8]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 1.
Rev. 0.6
D0
Si5338
Register 176.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP1[23:16]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP1[23:16]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 1.
Register 177.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP1[31:24]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP1[31:24]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 1.
Register 178.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP1[39:32]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP1[39:32]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 1.
Rev. 0.6
123
Si5338
Register 179.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP1[47:40]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP1[47:40]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 1.
Register 180.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
MS2_FIDP1[51:48]
Type
R/W
D0
Reset value = 0000 0000
Bit
Name
7:4
Unused
3:0
MS2_FIDP1[51:48]
Function
Unused.
MultiSynth2 Frequency Increment/Decrement Parameter 1.
Register 181.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
MS2_FIDP2[51:48]
Type
R/W
Reset value = 0000 0000
124
Bit
Name
7:4
Reserved
3:0
MS2_FIDP2[51:48]
Function
Reserved.
MultiSynth2 Frequency Increment/Decrement Parameter 2.
Rev. 0.6
D0
Si5338
Register 182.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP2[47:40]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP2[47:40]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 2.
Register 183.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP2[39:32]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP2[39:32]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 2.
Register 184.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP2[31:24]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP2[31:24]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 2.
Rev. 0.6
125
Si5338
Register 185.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP2[23:16]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP2[23:16]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 2.
Register 186.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP2[15:8]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP2[15:8]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 2.
Register 187.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP2[7:0]
Type
R/W
D2
D1
Reset value = 0000 0000
126
Bit
Name
7:0
MS2_FIDP2[7:0]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 2.
Rev. 0.6
D0
Si5338
Register 188.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP3[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP3[7:0]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 3.
Register 189.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP3[15:8]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP3[15:8]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 3.
Register 190.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP3[23:16]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP3[23:16]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 3.
Rev. 0.6
127
Si5338
Register 191.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP3[31:24]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP3[31:24]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 3.
Register 192.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP3[39:32]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP3[39:32]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 3.
Register 193.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP3[47:40]
Type
R/W
D2
D1
Reset value = 0000 0000
128
Bit
Name
7:0
MS2_FIDP3[47:40]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 3.
Rev. 0.6
D0
Si5338
Register 194.
Bit
D7
D6
D5
D4
D3
Name
MS2_FIDP3[55:48]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_FIDP3[55:48]
Function
MultiSynth2 Frequency Increment/Decrement Parameter 3.
Register 195.
Bit
D7
D6
D5
D4
D3
D2
Name
MS2_FIDP3[62:56]
Type
R/W
D1
D0
Reset value = 0000 0000
Bit
Name
7
Unused
6:0
MS2_FIDP3[62:56]
Function
Unused.
MultiSynth2 Frequency Increment/Decrement Parameter 3.
Register 196.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP1[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP1[7:0]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 1.
Rev. 0.6
129
Si5338
Register 197.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP1[15:8]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP1[15:8]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 1.
Register 198.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP1[23:16]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP1[23:16]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 1.
Register 199.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP1[31:24]
Type
R/W
D2
D1
Reset value = 0000 0000
130
Bit
Name
7:0
MS3_FIDP1[31:24]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 1.
Rev. 0.6
D0
Si5338
Register 200.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP1[39:32]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP1[39:32]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 1.
Register 201.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP1[47:40]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP1[47:40]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 1.
Register 202.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
MS3_FIDP1 [51:48]
Type
R/W
D0
Reset value = 0000 0000
Bit
Name
7:4
Unused
3:0
MS3_FIDP1 [51:48]
Function
Unused.
MultiSynth3 Frequency Increment/Decrement Parameter 1.
Rev. 0.6
131
Si5338
Register 203.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
MS3_FIDP2[51:48]
Type
R/W
D0
Reset value = 0000 0000
Bit
Name
7:4
Reserved
3:0
MS3_FIDP2[51:48]
Function
Reserved
MultiSynth3 Frequency Increment/Decrement Parameter 2.
Register 204.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP2[47:40]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP2[47:40]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 2.
Register 205.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP2[39:32]
Type
R/W
D2
D1
Reset value = 0000 0000
132
Bit
Name
7:0
MS3_FIDP2[39:32]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 2.
Rev. 0.6
D0
Si5338
Register 206.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP2[31:24]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP2[31:24]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 2.
Register 207.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP2[23:16]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP2[23:16]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 2.
Register 208.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP2[15:8]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP2[15:8]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 2.
Rev. 0.6
133
Si5338
Register 209.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP2[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP2[7:0]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 2.
Register 210.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP3[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP3[7:0]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 3.
Register 211.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP3[15:8]
Type
R/W
D2
D1
Reset value = 0000 0000
134
Bit
Name
7:0
MS3_FIDP3[15:8]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 3.
Rev. 0.6
D0
Si5338
Register 212.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP3[23:16]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP3[23:16]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 3.
Register 213.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP3[31:24]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP3[31:24]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 3.
Register 214.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP3[39:32]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP3[39:32]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 3.
Rev. 0.6
135
Si5338
Register 215.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP3[47:40]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP3[47:40]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 3.
Register 216.
Bit
D7
D6
D5
D4
D3
Name
MS3_FIDP3[55:48]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_FIDP3[55:48]
Function
MultiSynth3 Frequency Increment/Decrement Parameter 3.
Register 217.
Bit
D7
D6
D5
D4
D3
D2
Name
MS3_FIDP3[62:56]
Type
R/W
D1
Reset value = 0000 0000
136
Bit
Name
7
Unused
6:0
MS3_FIDP3[62:56]
Function
Unused
MultiSynth3 Frequency Increment/Decrement Parameter 3.
Rev. 0.6
D0
Si5338
Register 218.
Bit
D7
D6
D5
D4
D3
Name
PLL_LOL
Type
R
D2
LOS_FDBK LOS_CLKIN
R
R
D1
D0
SYS_CAL
R
Reset value = 0000 0000
Bit
Name
Function
7:5
Reserved
Reserved
4
PLL_LOL
PLL Loss of Lock (LOL).
Asserts when the two PFD inputs have a frequency difference > 1000 ppm.
This bit is held high during a POR_reset until the PLL has locked. This bit will not
chatter while the PLL is locking. PLL_LOL does not assert when the input from
IN1,IN2 or IN3 is lost. When PLL_LOL asserts, the part will automatically try to
re-acquire to the input clock. See Register 241[7].
3
LOS_FDBK
Loss of Signal on Feedback Clock from IN5,6 or IN4.
2
LOS_CLKIN
Loss of Signal on Input Clock from IN1,2 or IN3.
1
Reserved
Reserved
0
SYS_CAL
Device Calibration in Process.
Rev. 0.6
137
Si5338
Register 230.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
OEB_ALL
OEB_3
OEB_2
OEB_1
OEB_0
Type
R/W
R/W
R/W
R/W
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:5
Unused
4
OEB_ALL
Function
Unused.
Disable All Clock Outputs.
0: All output clocks are disabled
1: Output clocks are not disabled
3
OEB_3
CLK3 Disable.
0: CLK1 output is disabled
1: CLK1 output is not disabled
2
OEB_2
CLK2 Disable.
0: CLK2 output is disabled
1: CLK2 output is not disabled
1
OEB_1
CLK1 Disable.
0: CLK2 output is disabled
1: CLK2 output is not disabled
OEB_0
CLK0 Disable.
0: CLK0 output is disabled
1: CLK0 output is not disabled
0
Register 235.
Bit
D7
D6
D5
D4
D3
Name
FCAL[7:0]
Type
R
Reset value = xxxx xxxx
Bit
Name
7:0
FCAL[7:0]
138
Function
Bits 7:0 of the Frequency Calibration for the VCO.
Rev. 0.6
Si5338
Register 236.
Bit
D7
D6
D5
D4
D3
Name
FCAL[15:8]
Type
R
D2
D1
D0
D1
D0
Reset value = xxxx xxxx
Bit
Name
Function
7:0
FCAL[15:8]
Bits 15:8 of the Frequency Calibration for the VCO.
Register 237.
Bit
D7
D6
D5
D4
D3
D2
Name
Reserved
FCAL[17:16]
Type
R
R
Reset value = xxxx xxxx
Bit
Name
Function
7:2
Reserved
1:0
FCAL[17:16]
Reserved.
Bits 17:16 of the Frequency Calibration for the VCO.
Register 241.
Bit
D7
D6
Name
DIS_LOL
D5
D4
D3
D2
D1
D0
Reserved. Write to 0x65.
Type
R/W
Reset value = xxxx xxxx
Bit
Name
Function
7
DIS_LOL
When asserted, the PLL_LOL status in register 218 is prevented from
asserting.
6:0
Reserved
On a non-factory-programmed device this register must be set to 0x65.
On a factory programmed device, this register must stay 0x65.
Rev. 0.6
139
Si5338
Register 242.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
DCLK_DIS
Type
R/W
D0
Reset value = xxxx xxxx
Bit
Name
7:2
Reserved
1
DCLK_DIS
0
Reserved
Function
Reserved.
Disable Clock to INC/DEC State Machine.
When true, the frequency inc/dec logic is disabled, which saves about 2 mA of current.
See also Registers 52[4], 63[4], 74[4], 85[4].
Reserved.
Register 246.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
SOFT_RESET
Type
R/W
D0
R/W
Reset value = xxxx xxxx
Bit
Name
7:2
Reserved
1
0
140
Function
Reserved.
Soft Reset.
This reset will disable all clock outputs, then re-acquire the PLL to the input clock and
the enable all the clock outputs. Retains device configuration stored in RAM. Do not
SOFT_RESET
use read-modify-write procedure to perform soft reset. Instead, write reg246=0x02,
regardless of the current value of this bit. Reading this bit after a soft reset will return a
1.
Reserved
Reserved.
Rev. 0.6
Si5338
Register 247.
Bit
D7
D6
D5
Name
D4
D3
D2
PLL_LOL_STK LOS_FDBK_STK LOS_CLKIN_STK
Type
R/W
R/W
R/W
D1
D0
SYS_CAL_STK
R/W
Reset value = xxxx xxxx
Bit
Name
Function
7:5
Reserved
4
PLL_LOL_STK
3
LOS_FDBK_STK
Feedback Clock Loss of Signal Sticky Bit.
Sticky version of LOS_FDBK. See also Registers 6 and 218. Only a soft or
POR reset or writing a “0” to this bit will clear it.
2
LOS_CLKIN_STK
Input Clock Loss of Signal Sticky Bit.
Sticky version of LOS_CLKIN_STK. See also Registers 6 and 218. Only a soft
or POR reset or writing a “0” to this bit will clear it.
1
Reserved
0
SYS_CAL_STK
Reserved.
PLL Loss of Lock Sticky Bit.
Sticky version of PLL_LOL. See also Registers 6 and 218. Only a soft or POR
reset or writing a “0” to this bit will clear it.
Reserved.
System Calibration in Process Sticky Bit.
Sticky version of SYS_CAL. See also Registers 6 and 218. Only a soft or POR
reset or writing a “0” to this bit will clear it.
Rev. 0.6
141
Si5338
Register 255.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
PAGE_SEL
Type
R/W
Reset value = xxxx xxxx
Bit
Name
7:1
Unused
0
PAGE_SEL
Function
Unused.
Set to 0 to access registers 0–254, set to 1 to access register 256 to 347.
Register 287.
Bit
D7
D6
D5
D4
D3
Name
MS0_SSUPP2[7:0]
Type
R/W
D2
Reset value = 0000 0000
142
Bit
Name
7:0
MS0_SSUPP2[7:0]
Function
MultiSynth0 Spread Spectrum Up Parameter 2.
Rev. 0.6
D1
D0
Si5338
Register 288.
Bit
D7
D6
D5
D4
D3
D2
Name
MS0_SSUPP2[14:8]
Type
R/W
D1
D0
D1
D0
D1
D0
Reset value = 0000 0000
Bit
Name
7
Unused
6:0
MS0_SSUPP2[14:8]
Function
Unused.
MultiSynth0 Spread Spectrum Up Parameter 2.
Register 289.
Bit
D7
D6
D5
D4
D3
Name
MS0_SSUPP3[7:0]
Type
R/W
D2
Reset value = 0000 0000
Bit
Name
7:0
MS0_SSUPP3[7:0]
Function
MultiSynth0 Spread Spectrum Up Parameter 3.
Register 290.
Bit
D7
D6
D5
D4
D3
D2
Name
MS0_SSUPP3[14:8]
Type
R/W
Reset value = 0000 0000
Bit
Name
7
Unused
6:0
MS0_SSUPP3[14:8]
Function
Unused
MultiSynth0 Spread Spectrum Up Parameter 3.
Rev. 0.6
143
Si5338
Register 291.
Bit
D7
D6
D5
D4
D3
Name
MS0_SSUPP1[7:0]
Type
R/W
D2
D1
D0
D1
D0
Reset value = 0000 0000
Bit
Name
Function
7:0
MS0_SSUPP1[7:0]
MultiSynth0 Spread Spectrum Up Parameter 1.
Register 292.
Bit
D7
D6
D5
D4
D3
D2
Name
MS0_SSUDP1[3:0]
MS0_SSUPP1[11:8]
Type
R/W
R/W
Reset value = 0011 0001
Bit
Name
Function
7:4
MS0_SSUDP1[3:0]
MultiSynth0 Spread Spectrum Up/Down Parameter 1.
3:0
MS0_SSUPP1[11:8]
MultiSynth0 Spread Spectrum Up Parameter 1.
Register 293.
Bit
D7
D6
D5
D4
D3
Name
MS0_SSUDP1[11:4]
Type
R/W
D2
Reset value = 0011 0001
144
Bit
Name
7:0
MS0_SSUDP1[11:4]
Function
MultiSynth0 Spread Spectrum Up Parameter 1.
Rev. 0.6
D1
D0
Si5338
Register 294.
Bit
D7
D6
D5
D4
D3
Name
MS0_SSDNP2[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS0_SSDNP2[7:0]
Function
MultiSynth0 Spread Spectrum Down Parameter 2.
Register 295.
Bit
D7
D6
D5
D4
D3
D2
Name
MS0_SSDNP2[14:8]
Type
R/W
D1
D0
Reset value = 0000 0000
Bit
Name
7
Unused
6:0
MS0_SSDNP2[14:8]
Function
Unused.
MultiSynth0 Spread Spectrum Down Parameter 2.
Register 296.
Bit
D7
D6
D5
D4
D3
Name
MS0_SSDNP3[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0001
Bit
Name
7:0
MS0_SSDNP3[7:0]
Function
MultiSynth0 Spread Spectrum Down Parameter 3.
Rev. 0.6
145
Si5338
Register 297.
Bit
D7
D6
D5
D4
D3
D2
Name
MS0_SSDNP3[14:8]
Type
R/W
D1
D0
Reset value = 0000 0000
Bit
Name
Function
7
Unused
6:0
MS0_SSDNP3[14:8]
Unused.
MultiSynth0 Spread Spectrum Down Parameter 3.
Register 298.
Bit
D7
D6
D5
D4
D3
Name
MS0_SSDNP1[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
Function
7:0
MS0_SSDNP1[7:0]
MultiSynth0 Spread Spectrum Down Parameter 1.
Register 299.
Bit
D7
D6
D5
D4
Name
D3
D2
D1
MS0_SSDNP1[11:8]
Type
R/W
R/W
Reset value = 0011 0001
146
Bit
Name
7:4
Reserved
3:0
MS0_SSDNP1[11:8]
Function
Reserved.
MultiSynth0 Spread Spectrum Down Parameter 1.
Rev. 0.6
D0
Si5338
Register 303.
Bit
D7
D6
D5
D4
D3
Name
MS1_SSUPP2[7:0]
Type
R/W
D2
D1
D0
D1
D0
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS1_SSUPP2[7:0]
Function
MultiSynth1 Spread Spectrum Up Parameter 2.
Register 304.
Bit
D7
D6
D5
D4
D3
D2
Name
MS1_SSUPP2[14:8]
Type
R/W
Reset value = 0000 0000
Bit
Name
7
Unused
6:0
MS1_SSUPP2[14:8]
Function
Unused.
MultiSynth1 Spread Spectrum Up Parameter 2.
Register 305.
Bit
D7
D6
D5
D4
D3
Name
MS1_SSUPP3[7:0]
Type
R/W
D2
Reset value = 0000 0001
Bit
Name
7:0
MS1_SSUPP3[7:0]
Function
MultiSynth1 Spread Spectrum Up Parameter 3.
Rev. 0.6
147
Si5338
Register 306.
Bit
D7
D6
D5
D4
D3
D2
Name
MS1_SSUPP3[14:8]
Type
R/W
D1
D0
D1
D0
D1
D0
Reset value = 0000 0000
Bit
Name
Function
7
Unused
6:0
MS1_SSUPP3[14:8]
Unused.
MultiSynth1 Spread Spectrum Up Parameter 3.
Register 307.
Bit
D7
D6
D5
D4
D3
Name
MS1_SSUPP1[7:0]
Type
R/W
D2
Reset value = 0000 0000
Bit
Name
Function
7:0
MS1_SSUPP1[7:0]
MultiSynth1 Spread Spectrum Up Parameter 1.
Register 308.
Bit
D7
D6
D5
D4
D3
D2
Name
MS1_SSUDP1[3:0]
MS1_SSUPP1[11:8]
Type
R/W
R/W
Reset value = 1001 0000
148
Bit
Name
Function
7:4
MS1_SSUDP1[3:0]
MultiSynth1 Spread Spectrum Up/Down Parameter 1.
3:0
MS1_SSUPP1[11:8]
MultiSynth1 Spread Spectrum Up Parameter 1.
Rev. 0.6
Si5338
Register 309.
Bit
D7
D6
D5
D4
D3
Name
MS1_SSUDP1[11:4]
Type
R/W
D2
D1
D0
D1
D0
Reset value = 0011 0001
Bit
Name
7:0
MS1_SSUDP1[11:4]
Function
MultiSynth1 Spread Spectrum Up Parameter 1.
Register 310.
Bit
D7
D6
D5
D4
D3
Name
MS1_SSDNP2[7:0]
Type
R/W
D2
Reset value = 0000 0000
Bit
Name
7:0
MS1_SSDNP2[7:0]
Function
MultiSynth1 Spread Spectrum Down Parameter 2.
Register 311.
Bit
D7
D6
D5
D4
D3
D2
Name
MS1_SSDNP2[14:8]
Type
R/W
D1
D0
Reset value = 0000 0000
Bit
Name
7
Unused
6:0
MS1_SSDNP2[14:8]
Function
Unused.
MultiSynth1 Spread Spectrum Down Parameter 2.
Rev. 0.6
149
Si5338
Register 312.
Bit
D7
D6
D5
D4
D3
Name
MS1_SSDNP3[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0001
Bit
Name
7:0
MS1_SSDNP3[7:0]
Function
MultiSynth1 Spread Spectrum Down Parameter 3.
Register 313.
Bit
D7
D6
D5
D4
D3
D2
Name
MS1_SSDNP3[14:8]
Type
R/W
D1
D0
Reset value = 0000 0000
Bit
Name
7
Unused
6:0
MS1_SSDNP3[14:8]
Function
Unused.
MultiSynth1 Spread Spectrum Down Parameter 3.
Register 314.
Bit
D7
D6
D5
D4
D3
Name
MS1_SSDNP1[7:0]
Type
R/W
D2
D1
Reset value = 0000 0000
150
Bit
Name
7:0
MS1_SSDNP1[7:0]
Function
MultiSynth1 Spread Spectrum Down Parameter 1.
Rev. 0.6
D0
Si5338
Register 315.
Bit
D7
D6
D5
D4
D3
Name
D2
D1
D0
MS1_SSDNP1[11:8]
Type
R/W
R/W
Reset value = 0000 0000
Bit
Name
7:4
Reserved
3:0
MS1_SSDNP1[11:8]
Function
Reserved.
MultiSynth1 Spread Spectrum Down Parameter 1.
Register 319.
Bit
D7
D6
D5
D4
D3
Name
MS2_SSUPP2[7:0]
Type
R/W
D2
D1
D0
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_SSUPP2[7:0]
Function
MultiSynth2 Spread Spectrum Up Parameter 2.
Register 320.
Bit
D7
D6
D5
D4
D3
D2
Name
MS2_SSUPP2[14:8]
Type
R/W
Reset value = 0000 0000
Bit
Name
7
Unused
6:0
MS2_SSUPP2[14:8]
Function
Unused.
MultiSynth2 Spread Spectrum Up Parameter 2.
Rev. 0.6
151
Si5338
Register 321.
Bit
D7
D6
D5
D4
D3
Name
MS2_SSUPP3[7:0]
Type
R/W
D2
D1
D0
D1
D0
D1
D0
Reset value = 0000 0001
Bit
Name
7:0
MS2_SSUPP3[7:0]
Function
MultiSynth2 Spread Spectrum Up Parameter 3.
Register 322.
Bit
D7
D6
D5
D4
D3
D2
Name
MS2_SSUPP3[14:8]
Type
R/W
Reset value = 0000 0000
Bit
Name
7
Unused
6:0
MS2_SSUPP3[14:8]
Function
Unused.
MultiSynth2 Spread Spectrum Up Parameter 3.
Register 323.
Bit
D7
D6
D5
D4
D3
Name
MS2_SSUPP1[7:0]
Type
R/W
D2
Reset value = 0000 0000
152
Bit
Name
7:0
MS2_SSUPP1[7:0]
Function
MultiSynth2 Spread Spectrum Up Parameter 1.
Rev. 0.6
Si5338
Register 324.
Bit
D7
D6
D5
D4
D3
D2
D1
Name
MS2_SSUDP1[3:0]
MS2_SSUPP1[11:8]
Type
R/W
R/W
D0
Reset value = 1001 0000
Bit
Name
Function
7:4
MS2_SSUDP1[3:0]
MultiSynth2 Spread Spectrum Up/Down Parameter 1.
3:0
MS2_SSUPP1[11:8]
MultiSynth2 Spread Spectrum Up Parameter 1.
Register 325.
Bit
D7
D6
D5
D4
D3
Name
MS2_SSUDP1[11:4]
Type
R/W
D2
D1
D0
Reset value = 0011 0001
Bit
Name
7:0
MS2_SSUDP1[11:4]
Function
MultiSynth2 Spread Spectrum Up/Down Parameter 1.
Register 326.
Bit
D7
D6
D5
D4
D3
Name
MS2_SSDNP2[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS2_SSDNP2[7:0]
Function
MultiSynth2 Spread Spectrum Down Parameter 2.
Rev. 0.6
153
Si5338
Register 327.
Bit
D7
D6
D5
D4
D3
D2
Name
MS2_SSDNP2[14:8]
Type
R/W
D1
D0
Reset value = 0000 0000
Bit
Name
7
Unused
6:0
MS2_SSDNP2[14:8]
Function
Unused.
MultiSynth2 Spread Spectrum Down Parameter 2.
Register 328.
Bit
D7
D6
D5
D4
D3
Name
MS2_SSDNP3[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0001
Bit
Name
7:0
MS2_SSDNP3[7:0]
Function
MultiSynth2 Spread Spectrum Down Parameter 3.
Register 329.
Bit
D7
D6
D5
D4
D3
D2
Name
MS2_SSDNP3[14:8]
Type
R/W
D1
Reset value = 0000 0000
154
Bit
Name
7
Unused
6:0
MS2_SSDNP3[14:8]
Function
Unused.
MultiSynth2 Spread Spectrum Down Parameter 3.
Rev. 0.6
D0
Si5338
Register 330.
Bit
D7
D6
D5
D4
D3
Name
MS2_SSDNP1[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
Function
7:0
MS2_SSDNP1[7:0]
MultiSynth2 Spread Spectrum Down Parameter 1.
Register 331.
Bit
D7
D6
D5
D4
D3
Name
D2
D1
D0
MS2_SSDNP1[11:8]
Type
R/W
R/W
Reset value = 0000 0000
Bit
Name
7:4
Reserved
3:0
MS2_SSDNP1[11:8]
Function
Reserved.
MultiSynth2 Spread Spectrum Down Parameter 1.
Register 335.
Bit
D7
D6
D5
D4
D3
Name
MS3_SSUPP2[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_SSUPP2[7:0]
Function
MultiSynth3 Spread Spectrum Up Parameter 2.
Rev. 0.6
155
Si5338
Register 336.
Bit
D7
D6
D5
D4
D3
D2
Name
MS3_SSUPP2[14:8]
Type
R/W
D1
D0
D1
D0
D1
D0
Reset value = 0000 0000
Bit
Name
7
Unused
6:0
MS3_SSUPP2[14:8]
Function
Unused.
MultiSynth3 Spread Spectrum Up Parameter 2.
Register 337.
Bit
D7
D6
D5
D4
D3
Name
MS3_SSUPP3[7:0]
Type
R/W
D2
Reset value = 0000 0001
Bit
Name
7:0
MS3_SSUPP3[7:0]
Function
MultiSynth3 Spread Spectrum Up Parameter 3.
Register 338.
Bit
D7
D6
D5
D4
D3
D2
Name
MS3_SSUPP3[14:8]
Type
R/W
Reset value = 0000 0000
156
Bit
Name
7
Unused
6:0
MS3_SSUPP3[14:8]
Function
Unused.
MultiSynth3 Spread Spectrum Up Parameter 3.
Rev. 0.6
Si5338
Register 339.
Bit
D7
D6
D5
D4
D3
Name
MS3_SSUPP1[7:0]
Type
R/W
D2
D1
D0
D1
D0
Reset value = 0000 0000
Bit
Name
Function
7:0
MS3_SSUPP1[7:0]
MultiSynth3 Spread Spectrum Up Parameter 1.
Register 340.
Bit
D7
D6
D5
D4
D3
D2
Name
MS3_SSUDP1[3:0]
MS3_SSUPP1[11:8]
Type
R/W
R/W
Reset value = 1001 0000
Bit
Name
Function
7:4
MS3_SSUDP1[3:0]
MultiSynth3 Spread Spectrum Up/Down Parameter 1.
3:0
MS3_SSUPP1[11:8]
MultiSynth3 Spread Spectrum Up Parameter 1.
Register 341.
Bit
D7
D6
D5
D4
D3
Name
MS3_SSUDP1[11:4]
Type
R/W
D2
D1
D0
Reset value = 0011 0001
Bit
Name
7:0
MS3_SSUDP1[11:4]
Function
MultiSynth3 Spread Spectrum Up Parameter 2.
Rev. 0.6
157
Si5338
Register 342.
Bit
D7
D6
D5
D4
D3
Name
MS3_SSDNP2[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
7:0
MS3_SSDNP2[7:0]
Function
MultiSynth3 Spread Spectrum Down Parameter 2.
Register 343.
Bit
D7
D6
D5
D4
D3
D2
Name
MS3_SSDNP2[14:8]
Type
R/W
D1
D0
Reset value = 0000 0000
Bit
Name
7
Unused
6:0
MS3_SSDNP2[14:8]
Function
Unused.
MultiSynth3 Spread Spectrum Down Parameter 2.
Register 344.
Bit
D7
D6
D5
D4
D3
Name
MS3_SSDNP3[7:0]
Type
R/W
D2
D1
Reset value = 0000 0001
158
Bit
Name
7:0
MS3_SSDNP3[7:0]
Function
MultiSynth3 Spread Spectrum Down Parameter 3.
Rev. 0.6
D0
Si5338
Register 345.
Bit
D7
D6
D5
D4
D3
D2
Name
MS3_SSDNP3[14:8]
Type
R/W
D1
D0
Reset value = 0000 0000
Bit
Name
Function
7
Unused
6:0
MS3_SSDNP3[14:8]
Unused.
MultiSynth3 Spread Spectrum Down Parameter 3.
Register 346.
Bit
D7
D6
D5
D4
D3
Name
MS3_SSDNP1[7:0]
Type
R/W
D2
D1
D0
Reset value = 0000 0000
Bit
Name
Function
7:0
MS3_SSDNP1[7:0]
MultiSynth3 Spread Spectrum Down Parameter 1.
Register 347.
Bit
D7
D6
D5
D4
Name
D3
D2
D1
D0
MS3_SSDNP1[11:8]
Type
R/W
R/W
Reset value = 0000 0000
Bit
Name
7:4
Reserved
3:0
MS3_SSDNP1[11:8]
Function
Reserved.
MultiSynth3 Spread Spectrum Down Parameter 1.
Rev. 0.6
159
Si5338
RSVD_GND
CLK0B
VDDO0
SDA
24
Top View
CLK0A
VDD
7. Pin Descriptions
23
22
21
20
19
IN1 1
18 CLK1A
IN2 2
17 CLK1B
IN3 3
16 VDDO1
GND
GND
Pad
IN4 4
15 VDDO2
IN5 5
14 CLK2A
13 CLK2B
7
8
9
10
11
12
VDD
INTR
CLK3B
CLK3A
VDDO3
SCL
IN6 6
Note: Center pad must be tied to GND for normal operation.
Table 17. Si5338 Pin Descriptions
Pin #
Pin Name
I/O
Signal Type
Description
CLKIN/CLKINB.
1,2
160
IN1/IN2
I
Multi
These pins are used as the main differential clock input or as the
XTAL input. See "3.2. Input Stage" on page 17, Figure 3 and
Figure 4, for connection details. Clock inputs to these pins must be
ac-coupled. Keep the traces from pins 1,2 to the crystal as short as
possible and keep other signals and radiating sources away from
the crystal.
When not in use, leave IN1 unconnected and IN2 connected to
GND.
Rev. 0.6
Si5338
Table 17. Si5338 Pin Descriptions (Continued)
Pin #
Pin Name
I/O
Signal Type
Description
This pin can have one of the following functions depending on the
part number:
CLKIN (for Si5338A/B/C and Si5338N/P/Q devices only)
Provides a high-impedance clock input for single ended clock
signals. This input should be dc-coupled as shown in “3.2. Input
Stage”, Figure 3.
If this pin is not used, it should be connected to ground.
PINC (for Si5338D/E/F devices only)
3
IN3
I
Multi
Used as the phase increment pin. See "3.9.2. Output Phase
Increment/Decrement" on page 24 for more details. Minimum
pulse width of 100 ns is required for proper operation. If this pin is
not used, it should be connected to ground.
FINC (for Si5338G/H/J devices only)
Used as the frequency increment pin. See "3.9.1. Frequency
Increment/Decrement" on page 23 for more details. Minimum
pulse width of 100 ns is required for proper operation. If this pin is
not used, it should be connected to ground.
OEB (for Si5338K/L/M devices only)
Used as an output enable pin. 0 = All outputs enabled; 1 = All
outputs disabled. By default, outputs are tri-stated when disabled.
This pin can have one of the following functions depending on the
part number
I2C_LSB (for Si5338A/B/C and Si5338K/L/M devices only)
This is the LSB of the Si5338 I2C address. 0 = I2C address
70h (111 0000), 1 = I2C address 71h (111 0001).
FDBK (for Si5338N/P/Q devices only)
4
IN4
I
Multi
Provides a high-impedance feedback input for single-ended clock
signals. This input should be dc-coupled as shown in “3.2. Input
Stage”, Figure 3. If this pin is not used, it should be connected to
ground.
PDEC (for Si5338D/E/F) devices only)
Used as the phase decrement pin. See “3.9.2. Output Phase
Increment/Decrement” for more details. Minimum pulse width of
100 ns is required for proper operation. If this pin is not used, it
should be connected to ground.
FDEC (for Si5338G/H/J devices only)
Used as the frequency decrement pin. See “3.9.1. Frequency
Increment/Decrement” for more details. Minimum pulse width of
100 ns is required for proper operation. If this pin is not used, it
should be connected to ground.
Rev. 0.6
161
Si5338
Table 17. Si5338 Pin Descriptions (Continued)
Pin #
Pin Name
I/O
Signal Type
Description
FDBK/FDBKB.
5,6
7
8
9
10
11
12
13
14
162
IN5/IN6
VDD
INTR
CLK3B
CLK3A
VDDO3
SCL
CLK2B
CLK2A
I
VDD
O
O
O
VDD
I
O
O
Multi
These pins can be used as a differential feedback input in zero
delay mode or as a secondary clock input. See section 3.2,
Figure 3, for termination details. See "3.9.5. Zero-Delay Mode" on
page 24 for zero delay mode set-up. Inputs to these pins must be
ac-coupled.
When not in use, leave IN5 unconnected and IN6 connected to
GND.
Supply
Core Supply Voltage.
This is the core supply voltage, which can operate from a 1.8, 2.5,
or 3.3 V supply. A 0.1 µF bypass capacitor should be located very
close to this pin.
Open Drain
Interrupt.
A typical pullup resistor of 1–4 k is used on this pin. This pin can
be pulled up to a supply voltage as high as 3.6 V regardless of the
other supply voltages on pins 7, 11, 15, 16, 20, and 24. The interrupt condition allows the pull up resistor to pull the output up to the
supply voltage.
Multi
Output Clock B for Channel 3.
May be a single-ended output or half of a differential output with
CLK3A being the other differential half. If unused, leave this pin
floating.
Multi
Output Clock A for Channel 3.
May be a single-ended output or half of a differential output with
CLK3B being the other differential half. If unused, leave this pin
floating.
Supply
LVCMOS
Output Clock Supply Voltage.
Supply voltage (3.3, 2.5, 1.8, or 1.5 V) for CLK3A,B. A 0.1 µF
capacitor must be located very close to this pin. If CLK3 is not
used, this pin must be tied to VDD (pin 7, 24).
I2C Serial Clock Input.
This is the serial clock input for the I2C bus. A pullup resistor at this
pin is required. Typical values would be 1–4 k. See the I2C bus
spec for more information. This pin is 3.3 V tolerant regardless of
the other supply voltages on pins 7, 11, 15, 16, 20, 24.
Multi
Output Clock B for Channel 2.
May be a single-ended output or half of a differential output with
CLK2A being the other differential half. If unused, leave this pin
floating.
Multi
Output Clock A for Channel 2.
May be a single-ended output or half of a differential output with
CLK2B being the other differential half. If unused, leave this pin
floating.
Rev. 0.6
Si5338
Table 17. Si5338 Pin Descriptions (Continued)
Pin #
15
16
17
18
19
Pin Name
VDDO2
VDDO1
CLK1B
CLK1A
SDA
I/O
VDD
VDD
O
O
I/O
Signal Type
Description
Supply
Output Clock Supply Voltage.
Supply voltage (3.3, 2.5, 1.8, or 1.5 V) for CLK2A,B.
A 0.1 µF capacitor must be located very close to this pin. If CLK2 is
not used, this pin must be tied to VDD (pin 7, 24).
Supply
Output Clock Supply Voltage.
Supply voltage (3.3, 2.5, 1.8, or 1.5 V) for CLK1A,B.
A 0.1 µF capacitor must be located very close to this pin. If CLK1 is
not used, this pin must be tied to VDD (pin 7, 24).
Multi
Output Clock B for Channel 1.
May be a single-ended output or half of a differential output with
CLK1A being the other differential half. If unused, leave this pin
floating.
Multi
Output Clock A for Channel 1.
May be a single-ended output or half of a differential output with
CLK1B being the other differential half. If unused, leave this pin
floating.
LVCMOS
I2C Serial Data.
This is the serial data for the I2C bus. A pullup resistor at this pin is
required. Typical values would be 1–4 k. See the I2C bus spec
for more information. This pin is 3.3 V tolerant regardless of the
other supply voltages on pins 7, 11, 15, 16, 20, 24.
Output Clock Supply Voltage.
Supply voltage (3.3, 2.5, 1.8, or 1.5 V) for CLK0A,B.
A 0.1 µF capacitor must be located very close to this pin. If CLK0 is
not used, this pin must be tied to VDD (pin 7, 24).
20
VDDO0
VDD
Supply
21
CLK0B
O
Multi
Output Clock B for Channel 0.
May be a single-ended output or half of a differential output with
CLK0A being the other differential half. If unused, leave this pin
floating.
22
CLK0A
O
Multi
Output Clock A for Channel 0.
May be a single-ended output or half of a differential output with
CLK0B being the other differential half. If unused, leave this pin
floating.
23
GND
GND
GND
Ground.
Must be connected to system ground. Minimize the ground path
impedance for optimal performance of this device.
24
VDD
VDD
Supply
GND
PAD
GND
GND
GND
Core Supply Voltage.
The device operates from a 1.8, 2.5, or 3.3 V supply. A 0.1 µF
bypass capacitor should be located very close to this pin.
Ground Pad.
This is the large pad in the center of the package. Device
specifications cannot be guaranteed unless the ground pad is
properly connected to a ground plane on the PCB. See Table 20,
“PCB Land Pattern,” on page 167 for ground via requirements.
Rev. 0.6
163
Si5338
8. Device Pinout by Part Number
The Si5338 is orderable in three different speed grades: Si5338A/D/G/K/N have a maximum output clock
frequency limit of 710 MHz. Si5338B/E/H/L/P have a maximum output clock frequency of 350 MHz. Si5338C/F/J/
M/Q have a maximum output clock frequency of 200 MHz.
Devices are also orderable according to the pin control functions available on Pins 3 and 4:

CLKIN—single-ended clock input

I2C_LSB—determines the LSB bit of the 7-bit I2C address
FINC—frequency increment pin
FDEC—frequency decrement pin
PINC—phase increment pin
PDEC—phase decrement pin
FDBK—single-ended feedback input
OEB—output enable






Table 18. Pin Function by Part Number
Pin #
Si5338A: 710 MHz Si5338D: 710 MHz Si5338G: 710 MHz Si5338K: 710 MHz Si5338N: 710 MHz
Si5338B: 350 MHz Si5338E: 350 MHz Si5338H: 350 MHz Si5338L: 350 MHz Si5338P: 350 MHz
Si5338C: 200 MHz Si5338F: 200 MHz Si5338J: 200 MHz Si5338M: 200 MHz Si5338Q: 200 MHz
1
CLKIN1
CLKIN1
CLKIN1
CLKIN1
CLKIN1
2
CLKINB1
CLKINB1
CLKINB1
CLKINB1
CLKINB1
3
CLKIN2
PINC
FINC
OEB
CLKIN2
4
I2C_LSB
PDEC
FDEC
I2C_LSB
FDBK3
5
FDBK4
FDBK4
FDBK4
FDBK4
FDBK4
6
FDBKB4
FDBKB4
FDBKB4
FDBKB4
FDBKB4
7
VDD
VDD
VDD
VDD
VDD
8
INTR
INTR
INTR
INTR
INTR
9
CLK3B
CLK3B
CLK3B
CLK3B
CLK3B
10
CLK3A
CLK3A
CLK3A
CLK3A
CLK3A
11
VDDO3
VDDO3
VDDO3
VDDO3
VDDO3
12
SCL
SCL
SCL
SCL
SCL
13
CLK2B
CLK2B
CLK2B
CLK2B
CLK2B
14
CLK2A
CLK2A
CLK2A
CLK2A
CLK2A
15
VDDO2
VDDO2
VDDO2
VDDO2
VDDO2
16
VDDO1
VDDO1
VDDO1
VDDO1
VDDO1
Notes:
1. CLKIN/CLKINB on pins 1 and 2 are differential clock inputs or XTAL inputs.
2. CLKIN on pin 3 is a single-ended clock input.
3. FDBK on pin 4 is a single-ended feedback input.
4. FDBK/FDBKB on pins 5 and 6 are differential feedback inputs.
164
Rev. 0.6
Si5338
Table 18. Pin Function by Part Number (Continued)
Pin #
Si5338A: 710 MHz Si5338D: 710 MHz Si5338G: 710 MHz Si5338K: 710 MHz Si5338N: 710 MHz
Si5338B: 350 MHz Si5338E: 350 MHz Si5338H: 350 MHz Si5338L: 350 MHz Si5338P: 350 MHz
Si5338C: 200 MHz Si5338F: 200 MHz Si5338J: 200 MHz Si5338M: 200 MHz Si5338Q: 200 MHz
17
CLK1B
CLK1B
CLK1B
CLK1B
CLK1B
18
CLK1A
CLK1A
CLK1A
CLK1A
CLK1A
19
SDA
SDA
SDA
SDA
SDA
20
VDDO0
VDDO0
VDDO0
VDDO0
VDDO0
21
CLK0B
CLK0B
CLK0B
CLK0B
CLK0B
22
CLK0A
CLK0A
CLK0A
CLK0A
CLK0A
23
GND
GND
GND
GND
GND
24
VDD
VDD
VDD
VDD
VDD
Notes:
1. CLKIN/CLKINB on pins 1 and 2 are differential clock inputs or XTAL inputs.
2. CLKIN on pin 3 is a single-ended clock input.
3. FDBK on pin 4 is a single-ended feedback input.
4. FDBK/FDBKB on pins 5 and 6 are differential feedback inputs.
Rev. 0.6
165
Si5338
9. Package Outline: 24-Lead QFN
Figure 24. 24-Lead Quad Flat No-lead (QFN)
Table 19. Package Dimensions
Dimension
Min
Nom
Max
A
0.80
0.85
0.90
A1
0.00
0.02
0.05
b
0.18
0.25
0.30
D
D2
4.00 BSC.
2.35
2.50
e
0.50 BSC.
E
4.00 BSC.
2.65
E2
2.35
2.50
2.65
L
0.30
0.40
0.50
aaa
0.10
bbb
0.10
ccc
0.08
ddd
0.10
eee
0.05
Notes:
1.
2.
3.
4.
166
All dimensions shown are in millimeters (mm) unless otherwise noted.
Dimensioning and Tolerancing per ANSI Y14.5M-1994.
This drawing conforms to the JEDEC Outline MO-220, variation VGGD-8.
Recommended card reflow profile is per the JEDEC/IPC J-STD-020C specification for Small Body
Components.
Rev. 0.6
Si5338
10. Recommended PCB Layout
Table 20. PCB Land Pattern
Dimension
Min
Nom
Max
P1
2.50
2.55
2.60
P2
2.50
2.55
2.60
X1
0.20
0.25
0.30
Y1
0.75
0.80
0.85
C1
3.90
C2
3.90
E
0.50
Notes:
General
1.
2.
3.
4.
All dimensions shown are in millimeters (mm) unless otherwise noted.
Dimensioning and Tolerancing per ANSI Y14.5M-1994 specification.
This Land Pattern Design is based on the IPC-7351 guidelines.
Center pad should be connected to the nearest GND plane.
Solder Mask Design
5. All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder mask and the metal pad is
to be 60 µm minimum, all the way around the pad.
Stencil Design
6. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be used to assure good solder
paste release.
7. The stencil thickness should be 0.125 mm (5 mils).
8. The ratio of stencil aperture to land pad size should be 1:1 for all perimeter pins.
9. A 2x2 array of 1.0 mm square openings on 1.25 mm pitch should be used for the center ground pad.
Card Assembly
10. A No-Clean, Type-3 solder paste is recommended.
11. The recommended card reflow profile is per the JEDEC/IPC J-STD-020C specification for Small Body Components.
Rev. 0.6
167
Si5338
11. Ordering Information
Si5338X
AXXXXX
GMR
Operating Temp Range: -40 to +85 °C
Package: 4 x 4 mm QFN, ROHS6, Pb-free
R = Tape & Reel
(blank) = Tubes
A = Product Revision A
XXXXX = NVM code (optional).
For blank devices, order Si5338X-A-GM(R).
For custom NVM configurations, a unique 5-digit ordering code
will be assigned by the factory. Consult your sales representative
for custom NVM configurations.
Si5338A
Si5338B
Si5338C
Si5338D
Si5338E
Si5338F
Si5338G
Si5338H
Si5338J
Si5338K
Si5338L
Si5338M
Si5338N
Si5338P
Si5338Q
-
0.16 MHz to 710 MHz I2C_LSB
0.16 MHz to 350 MHz I2C_LSB
0.16 MHz to 200 MHz I2C_LSB
0.16 MHz to 710 MHz Phase Inc/Dec Pin Control
0.16 MHz to 350 MHz Phase Inc/Dec Pin Control
0.16 MHz to 200 MHz Phase Inc/Dec Pin Control
0.16 MHz to 710 MHz Freq Inc/Dec Pin Control
0.16 MHz to 350 MHz Freq Inc/Dec Pin Control
0.16 MHz to 200 MHz Freq Inc/Dec Pin Control
0.16 MHz to 710 MHz OEB Pin Control + I2C_LSB
0.16 MHz to 350 MHz OEB Pin Control + I2C_LSB
0.16 MHz to 200 MHz OEB Pin Control + I2C_LSB
0.16 MHz to 710 MHz Four Inputs (2 Differential, 2 Single-ended)
0.16 MHz to 350 MHz Four Inputs (2 Differential, 2 Single-ended)
0.16 MHz to 200 MHz Four Inputs (2 Differential, 2 Single-ended)
Evaluation Boards
Si5338
168
EVB
Si5338 Evaluation Board
PROG - EVB
Si5338 Field Programmer
Rev. 0.6
Si5338
DOCUMENT CHANGE LIST
Revision 0.5 to 0.55

Revision 0.1 to 0.2














Updated block diagram to show Rn output divider
and PLL bypass mode
Updated pin description to include FDBK±
Updated Table 3. DC Characteristics
Updated Table 12. Jitter Specifications
Added Supply Current vs. Output Frequency
Updated package outline specification
Clarified input clock configuration register settings
Updated DRV_INVERTn[1:0] settings
Added PLL bypass mode
Added LOS_FDBK description
Added additional detail to phase increment/
decrement and frequency increment/decrement
descriptions
Clarified output driver powerdown options
Clarified entry to self-calibration mode
Updated ordering guide

















Changed output duty cycle to 45–55%.

All I2C address now in binary.
Changed ordering information to reflect 710 MHz
limit.
Info on POR and soft reset added.
Updated Figure 14 on page 24.
Added register section.
Update programming procedure in “3.5. Configuring
the Si5338” to improve robustness.
Updated Figure 9 to include the entire programming
procedure.
Added "3.2.1. Loss-of-Signal (LOS) Alarm
Detectors" on page 17 to show the location of the
LOS detector circuits.
Updated input circuit diagrams in "3.2. Input Stage"
on page 17.
Update block diagrams with new input circuit
diagrams.





Changed minimum output clock frequency from
5 MHz to 1 MHz.
Updated slew rates.
Updated " Features" on page 1.
Updated Table 6, “Input and Output Clock
Characteristics,” on page 7.
Deleted Table 12, “Output Driver Slew Rate Control”.




Revision 0.3 to 0.5

Added GbE RM jitter specification with 1.875–
20 MHz integration band.
Revision 0.55 to 0.6
Revision 0.2 to 0.3

Editorial changes to section 3.5 “Configuring the
Si5338” to improve clarity on ordering custom
Si5338 and on configuring "blank" Si5338.
Added pin numbers to device package drawings.
Updated ordering information to include evaluation
boards.
Updated first page description and applications
Added JC to specification tables.
Major editorial changes to all sections to improve
clarity
Completed electrical specification tables with final
characterization results
Revised the maximum input and output frequencies
from 700 MHz to 710 MHz
Improved jitter specifications to reflect updated
characterization results
Added new Si5338N/P/Q ordering codes
Added typical application diagrams
Added an application section to highlight the
flexibility of the Si5338 in various timing functions
Added a configuration section to clarify configuration
options
Rev. 0.6
169
Si5338
CONTACT INFORMATION
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Austin, TX 78701
Tel: 1+(512) 416-8500
Fax: 1+(512) 416-9669
Toll Free: 1+(877) 444-3032
Please visit the Silicon Labs Technical Support web page:
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and register to submit a technical support request.
The information in this document is believed to be accurate in all respects at the time of publication but is subject to change without notice.
Silicon Laboratories assumes no responsibility for errors and omissions, and disclaims responsibility for any consequences resulting from
the use of information included herein. Additionally, Silicon Laboratories assumes no responsibility for the functioning of undescribed features
or parameters. Silicon Laboratories reserves the right to make changes without further notice. Silicon Laboratories makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Silicon Laboratories assume any liability
arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. Silicon Laboratories products are not designed, intended, or authorized for use in applications intended to
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170
Rev. 0.6