Si5341/40 Data Sheet

S i 5 3 4 1/40
L O W - J I T T E R, 1 0 - O U T P U T , A NY -F R E Q U E N C Y, A NY -O U T P U T
CLOCK GENERATOR
Features









Generates up to 10 independent

output clocks
Ultra-low jitter: <100 fs RMS typical 
MultiSynth™ technology enables anyfrequency synthesis on any-output

Highly configurable outputs
compatible with LVDS, LVPECL, CML, 
LVCMOS, HCSL, or programmable 
voltage
Input frequency range:

External crystal: 25, 48-54 MHz
Differential clock: 10 to 750 MHz

LVCMOS clock: 10 to 250 MHz
Output frequency range:
Differential: 100 Hz to 712.5 MHz

LVCMOS: 100 Hz to 250 MHz
Output-output skew: 20 ps typ

Adjustable output-output delay
Optional zero delay mode

Independent glitchless on-the-fly

output frequency changes
DCO mode with frequency steps as
low as 0.001 ppb
Independent output clock supply pins:
3.3 V, 2.5 V, or 1.8 V
Built-in power supply filtering and
regulation
Status monitoring: LOS, LOL
Serial Interface: I2C or SPI (3-wire or
4-wire)
User programmable (2x) non-volatile
OTP memory
ClockBuilderTM Pro software utility
simplifies device configuration and
assigns customer part numbers
Si5341: 4 input, 10 output, compact
9x9 mm, 64 QFN
Si5340: 4 input, 4 output, compact
7x7 mm, 44 QFN
Temperature range: –40 to +85 °C
Pb-free, RoHS-6 compliant
Ordering Information
See Section 8.
Functional Block Diagram
Si5341/40
Max Output Frequency
712.5 MHz
350 MHz
712.5 MHz
350 MHz
IN0
÷INT
Frequency Synthesis Mode
IN1
÷INT
Integer + Fractional
IN2
÷INT
Integer Only
Clock tree generation replacing XOs,
buffers, signal format translators
 Any-frequency clock translation
 Clocking for FPGAs, processors,
memory




OSC
XB
÷INT
Ethernet switches/routers
OTN framers/mappers/processors
Test equipment & instrumentation
Broadcast video
OUT0
Multi
Synth
÷INT
OUT1
Multi
Synth
÷INT
OUT2
Multi
Synth
÷INT
OUT3
Multi
Synth
÷INT
OUT4
÷INT
OUT5
NVM
÷INT
OUT6
I2C/SPI
÷INT
OUT7
The Si5341/40 can be quickly and easily configured using ClockBuilder Pro software.
Custom part numbers are automatically assigned using a ClockBuilder Pro for fast,
free, and easy factory pre-programming, or the Si5341/40 can be programmed incircuit via I2C and SPI serial interfaces.
Control/
Status
÷INT
OUT8
÷INT
OUT9
Rev. 1.0 7/15
Copyright © 2015 by Silicon Laboratories
Si5341
÷INT
Si5340
Multi
Synth
Description
The any-frequency, any-output Si5341/40 clock generators combine a wide-band PLL
with proprietary MultiSynth fractional synthesizer technology to offer a versatile and
high performance clock generator platform. This highly flexible architecture is capable
of synthesizing a wide range of integer and non-integer related frequencies up to
712.5 MHz on 10 differential clock outputs while delivering sub-100 fs rms phase jitter
performance with 0 ppm error. Each of the clock outputs can be assigned its own
format and output voltage enabling the Si5341/40 to replace multiple clock ICs and
oscillators with a single device making it a true “clock tree on a chip”.
PLL
XA
FB_IN
Applications

7x7 mm
IN_SEL[1:0]
Device Selector Guide
Grade
Si534xA
Si534xB
Si534xC
Si534xD
9x9 mm
XTAL

Si5341/40
Si5341/40
2
Rev. 1.0
Si5341/40
TABLE O F C ON TENTS
1. Typical Application Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
3. Typical Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4. Detailed Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.1. Power-up and Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.2. Frequency Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5.3. Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5.4. Fault Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
5.5. Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
5.6. Power Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
5.7. In-Circuit Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
5.8. Serial Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
5.9. Custom Factory Preprogrammed Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
5.10. Enabling Features and/or Configuration Settings Not Available in ClockBuilder Pro
for Factory Pre-programmed Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
6. Register Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
6.1. Addressing Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
6.2. High-Level Register Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
7. Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
8. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
9. Package Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
9.1. Si5341 9x9 mm 64-QFN Package Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
9.2. Si5340 7x7 mm 44-QFN Package Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
10. PCB Land Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
11. Top Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
12. Device Errata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Rev. 1.0
3
Si5341/40
1. Typical Application Schematic
161.1328125
MHz
Buffer
Buffer
2x 161.1328125 MHz
LVDS
133.33 MHz
2x 133.33 MHz
1.8V LVCMOS
Buffer
125 MHz
Level
Translator
Delay Line
3x 125 MHz
LVPECL
Buffer
Clock
Generator
Level
Translator
XA
4x 125 MHz
3.3V LVCMOS
200 MHz
2.5V LVCMOS
25 MHz
XB
“Traditional Discrete” Clock Tree
One Si5341 replaces:
3x crystal oscillators (XO)
2x buffers
1x Clock Generator
2x level translators
1x delay line
1x 161.1328125 MHz
LVDS
1x 161.1328125 MHz
LVDS
XA
2x 133.33 MHz
1.8V LVCMOS
25 MHz
XB
Si5341
1x 125 MHz
LVPECL
1x 125 MHz
LVPECL
1x 125 MHz
LVPECL
2x 125 MHz
3.3V LVCMOS
2x 125 MHz
3.3V LVCMOS
2x 200 MHz
2.5V LVCMOS
“Clock Tree
On-a-Chip”
2x 200 MHz
2.5V LVCMOS
Figure 1. Using The Si5341 to Replace a Traditional Clock Tree
4
Rev. 1.0
Si5341/40
2. Electrical Specifications
Table 1. Recommended Operating Conditions
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%,TA = –40 to 85 °C)
Parameter
Ambient Temperature
Symbol
TA
Min
–40
Typ
25
Max
85
Units
°C
Junction Temperature
TJMAX
—
—
125
°C
Core Supply Voltage
VDD
1.71
1.80
1.89
V
VDDA
3.14
3.30
3.47
V
VDDO
3.14
3.30
3.47
V
2.38
2.50
2.62
V
1.71
1.80
1.89
V
Output Driver Supply Voltage
*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.
Rev. 1.0
5
Si5341/40
Table 2. DC Characteristics
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%, VDDO = 1.8 V ±5%, 2.5 V ±5%, or 3.3 V ±5%, TA = –40 to 85 °C)
Parameter
Core Supply Current
Symbol
IDD
Test Condition
Si5341
Note 1
IDDA
Output Buffer Supply Current
IDDOx
Total Power Dissipation
Pd
Si5340
Note 2
Min
—
—
Si5341
Note 1
—
115
125
mA
Si5340
Note 2
—
115
125
mA
LVPECL Output3
@ 156.25 MHz
—
21
25
mA
LVDS Output3
@ 156.25 MHz
—
15
18
mA
3.3 V LVCMOS4 output
@ 156.25 MHz
—
21
25
mA
2.5 V LVCMOS4 output
@ 156.25 MHz
—
16
18
mA
1.8 V LVCMOS4 output
@ 156.25 MHz
—
12
13
mA
Si5341
Notes 1,5
—
830
980
mW
Si5340
2,5
—
685
815
mW
Notes
Typ
100
85
Max
150
130
Units
mA
mA
Notes:
1. Si5341 test configuration: 7 x 2.5 V LVDS outputs enabled @156.25 MHz. Excludes power in termination resistors.
2. Si5340 test configuration: 4 x 2.5 V LVDS outputs enabled @ 156.25 MHz. Excludes power in termination resistors.
3. Differential outputs terminated into an ac-coupled 100 load.
4. LVCMOS outputs measured into a 6-inch 50  PCB trace with 5 pF load. The LVCMOS outputs were set to
OUTx_CMOS_DRV=3, which is the strongest driver setting. Refer to the Si5341/40 Family Reference Manual for more
details on register settings.
Differential Output Test Configuration
IDDO
OUT
50
LVCMOS Output Test Configuration
IDDO
0.1 uF
100
OUT
50
6 inch
OUTa
OUTb
50
5 pF
0.1 uF
5. Detailed power consumption for any configuration can be estimated using ClockBuilderPro when an evaluation board
(EVB) is not available. All EVBs support detailed current measurements for any configuration.
6
Rev. 1.0
Si5341/40
Table 3. Input Specifications
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%, TA = –40 to 85 °C)
Parameter
Symbol
Test Condition
Min
Typ
Max
Units
Differential or Single-Ended/LVCMOS — AC-Coupled (IN0/IN0, IN1/IN1, IN2/IN2, FB_IN/FB_IN)
Input Frequency Range
Input Voltage Swing5
fIN
VIN
Differential
10
—
750
MHz
Single-ended/LVCMOS
10
—
250
Differential AC Coupled
fin < 250 MHz
100
—
1800
mVpp_se
Differential AC Coupled
250 MHz < fin < 750 MHz
225
—
1800
mVpp_se
Single-ended AC Coupled
fin < 250 MHz
100
—
3600
mVpp_se
Slew Rate1, 2
SR
400
—
—
V/µs
Duty Cycle
DC
40
—
60
%
Capacitance
CIN
—
2
—
pF
DC-Coupled CMOS Input Buffer (IN0, IN1, IN2)4
Input Frequency
fIN
10
—
250
MHz
Input Voltage
VIL
–0.2
—
0.33
V
VIH
0.49
—
—
V
SR
400
—
—
V/µs
Slew Rate
1, 2
Duty Cycle
DC
Clock Input
40
—
60
%
Minimum Pulse Width
PW
Pulse Input
1.6
—
—
ns
Input Resistance
RIN
—
8
—
kΩ
48
—
200
MHz
10
—
200
MHz
365
—
2000
mVpp_se
Differential or Single-Ended/LVCMOS Clock at XA/XB
Input Frequency Range
Input Single-ended Voltage Swing
fIN
Frequency range for best
output
jitter performance
VIN_SE
Notes:
1. Imposed for jitter performance.
2. Rise and fall times can be estimated using the following simplified equation: tr/tf80-20 = ((0.8 - 0.2) * VIN_Vpp_se) / SR.
3. VDDIO is determined by the IO_VDD_SEL bit. It is selectable as VDDA or VDD.
4. DC-coupled CMOS Input Buffer selection is not supported in ClockBuilder Pro for new designs. For single-ended
LVCMOS inputs to IN0,1,2 it is required to ac-couple into the differential input buffer.
5. Voltage swing is specified as single-ended mVpp.
6. Contact Silicon Labs Technical Support for more details.
Rev. 1.0
7
Si5341/40
Table 3. Input Specifications
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%, TA = –40 to 85 °C)
Parameter
Input Differential Voltage Swing
Symbol
Test Condition
VIN_DIFF
Slew rate1, 2
SR
Input Duty Cycle
DC
Imposed for best jitter performance
Min
Typ
Max
Units
365
—
2500
mVpp_diff
400
—
—
V/µs
40
—
60
%
Notes:
1. Imposed for jitter performance.
2. Rise and fall times can be estimated using the following simplified equation: tr/tf80-20 = ((0.8 - 0.2) * VIN_Vpp_se) / SR.
3. VDDIO is determined by the IO_VDD_SEL bit. It is selectable as VDDA or VDD.
4. DC-coupled CMOS Input Buffer selection is not supported in ClockBuilder Pro for new designs. For single-ended
LVCMOS inputs to IN0,1,2 it is required to ac-couple into the differential input buffer.
5. Voltage swing is specified as single-ended mVpp.
6. Contact Silicon Labs Technical Support for more details.
Table 4. Control Input Pin Specifications
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%, VDDS = 3.3 V ±5%, 1.8 V ±5%, TA = –40 to 85 °C)
Parameter
Symbol
Test Condition
Min
Typ
Max
Units
Si5341 Control Input Pins
(I2C_SEL, IN_SEL[1:0], RST, OE, SYNC, A1, SCLK, A0/CS, FINC, FDEC, SDA/SDIO)
Input Voltage
VIL
—
—
0.3xVDDIO*
V
VIH
0.7xVDDIO*
—
—
V
Input Capacitance
CIN
—
2
—
pF
Input Resistance
RIN
—
20
—
k
Minimum Pulse Width
TPW
RST, SYNC,
FINC, and FDEC
100
—
—
ns
Frequency Update Rate
FUR
FINC and FDEC
—
—
1
MHz
Si5340 Control Input Pins (I2C_SEL, IN_SEL[1:0], RST, OE, A1, SDA, SDI, SCLK, A0/CS, SDA/SDIO)
Input Voltage
VIL
—
—
0.3xVDDIO*
V
VIH
0.7xVDDIO*
—
—
V
Input Capacitance
CIN
—
2
—
pF
Input Resistance
RIN
—
20
—
k
Minimum Pulse Width
TPW
100
—
—
ns
RST only
*Note: VDDIO is determined by the IO_VDD_SEL bit. It is selectable as VDDA or VDD. Refer to the Reference Manual for more
details on register settings.
8
Rev. 1.0
Si5341/40
Table 5. Differential Clock Output Specifications
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%, VDDO = 1.8 V ±5%, 2.5 V ±5%, or 3.3 V ±5%, TA = –40 to 85 °C)
Parameter
Symbol
Output Frequency
fOUT
Duty Cycle
DC
Output-Output Skew
TSK
OUT-OUT Skew
TSK_OUT
Test Condition
Min
Typ
Max
Units
0.0001
—
712.5
MHz
fOUT < 400 MHz
48
—
52
%
400 MHz < fOUT <
712.5 MHz
45
—
55
%
Outputs on same Multisynth,
Normal Mode
—
20
50
ps
Outputs on same Multisynth,
Pow Power Mode
—
20
100
ps
Measured from the positive
to negative output pins
—
0
100
ps
mVpp_se
Output Amplitude1, 5
Normal Mode
VOUT
VDDO = 3.3 V,
2.5 V, or 1.8 V
LVDS
350
470
550
VDDO = 3.3 V
or 2.5 V
LVPECL
660
810
1000
Low Power Mode
VOUT
VDDO = 3.3 V,
2.5 V, or 1.8 V
LVDS
300
420
530
VDDO = 3.3 V
or 2.5 V
LVPECL
620
820
1060
mVpp_se
Notes:
1. The typical normal mode (or low power mode) LVDS maximum is 100 mV (or 80 mV) higher than the TIA/EIA-644
maximum. For normal and low-power modes, the amplitudes are programmable through register settings and can be
stored in NVM. Each output driver can be programmed independently. See Appendix A of the Si5341/40 Reference
Manual.
2. Driver output impedance depends on selected output mode (Normal, Low Power).
3. Measured for 156.25 MHz carrier frequency. Sinewave noise added to VDDO (1.8 V = 50 mVpp, 2.5 V/
3.3 V = 100 mVpp) and noise spur amplitude measured.
OUTx
Vcm
Vpp_se
Vcm
Vpp_se
Vpp_diff = 2*Vpp_se
OUTx
4. Measured across two adjacent outputs, both in LVDS mode, with the victim running at 155.52 MHz and the aggressor
at 156.25 MHz. Refer to application note, “AN862: Optimizing Si534x Jitter Performance in Next Generation Internet
Infrastructure Systems”, guidance on crosstalk minimization.
5. For other amplitudes see Appendix A of the Si5341/40 Reference Manual.
6. See Note 4, but in this case the measurement is across two output clocks that have a single clock between them.
7. Same as Note 4, but the Si5340 has less crosstalk due to the spacing of adjacent outputs.
Rev. 1.0
9
Si5341/40
Table 5. Differential Clock Output Specifications (Continued)
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%, VDDO = 1.8 V ±5%, 2.5 V ±5%, or 3.3 V ±5%, TA = –40 to 85 °C)
Parameter
Common Mode Voltage
Symbol
Test Condition
1
Min
Typ
Max
Units
V
Normal Mode or Low Power Modes
VCM
VDDO = 3.3 V
LVDS
1.10
1.25
1.35
LVPECL
1.90
2.05
2.15
VDDO = 2.5 V
LVPECL
LVDS
1.15
1.25
1.35
VDDO = 1.8 V
Sub-LVDS
0.87
0.93
1.0
Normal Mode
—
170
240
Low Power Mode
—
300
430
Normal Mode
—
100
—

Low Power Mode
—
650
—

dBc
tR/tF
Rise and Fall Times
(20% to 80%)
Differential Output Impedance2
Power Supply Noise Rejection
3
ZO
ps
Normal Mode
PSRR
10 kHz sinusoidal noise
—
–93
—
100 kHz sinusoidal noise
—
–93
—
500 kHz sinusoidal noise
—
–84
—
1 MHz sinusoidal noise
—
–79
—
Low Power Mode
10 kHz sinusoidal noise
—
–98
—
100 kHz sinusoidal noise
—
–95
—
500 kHz sinusoidal noise
—
–84
—
1 MHz sinusoidal noise
—
–76
—
dBc
Notes:
1. The typical normal mode (or low power mode) LVDS maximum is 100 mV (or 80 mV) higher than the TIA/EIA-644
maximum. For normal and low-power modes, the amplitudes are programmable through register settings and can be
stored in NVM. Each output driver can be programmed independently. See Appendix A of the Si5341/40 Reference
Manual.
2. Driver output impedance depends on selected output mode (Normal, Low Power).
3. Measured for 156.25 MHz carrier frequency. Sinewave noise added to VDDO (1.8 V = 50 mVpp, 2.5 V/
3.3 V = 100 mVpp) and noise spur amplitude measured.
OUTx
Vcm
Vpp_se
Vcm
Vpp_se
Vpp_diff = 2*Vpp_se
OUTx
4. Measured across two adjacent outputs, both in LVDS mode, with the victim running at 155.52 MHz and the aggressor
at 156.25 MHz. Refer to application note, “AN862: Optimizing Si534x Jitter Performance in Next Generation Internet
Infrastructure Systems”, guidance on crosstalk minimization.
5. For other amplitudes see Appendix A of the Si5341/40 Reference Manual.
6. See Note 4, but in this case the measurement is across two output clocks that have a single clock between them.
7. Same as Note 4, but the Si5340 has less crosstalk due to the spacing of adjacent outputs.
10
Rev. 1.0
Si5341/40
Table 5. Differential Clock Output Specifications (Continued)
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%, VDDO = 1.8 V ±5%, 2.5 V ±5%, or 3.3 V ±5%, TA = –40 to 85 °C)
Parameter
Symbol
Output-Output Crosstalk
Test Condition
XTALK
Min
Typ
Max
Units
Note
4
—
–75
—
dBc
Si5341
Note
6
—
–85
—
dBc
Si5340
Note 7
—
–85
—
dBc
Si5341
Notes:
1. The typical normal mode (or low power mode) LVDS maximum is 100 mV (or 80 mV) higher than the TIA/EIA-644
maximum. For normal and low-power modes, the amplitudes are programmable through register settings and can be
stored in NVM. Each output driver can be programmed independently. See Appendix A of the Si5341/40 Reference
Manual.
2. Driver output impedance depends on selected output mode (Normal, Low Power).
3. Measured for 156.25 MHz carrier frequency. Sinewave noise added to VDDO (1.8 V = 50 mVpp, 2.5 V/
3.3 V = 100 mVpp) and noise spur amplitude measured.
OUTx
Vcm
Vpp_se
Vcm
Vpp_se
Vpp_diff = 2*Vpp_se
OUTx
4. Measured across two adjacent outputs, both in LVDS mode, with the victim running at 155.52 MHz and the aggressor
at 156.25 MHz. Refer to application note, “AN862: Optimizing Si534x Jitter Performance in Next Generation Internet
Infrastructure Systems”, guidance on crosstalk minimization.
5. For other amplitudes see Appendix A of the Si5341/40 Reference Manual.
6. See Note 4, but in this case the measurement is across two output clocks that have a single clock between them.
7. Same as Note 4, but the Si5340 has less crosstalk due to the spacing of adjacent outputs.
Table 6. Output Status Pin Specifications
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%, VDDS = 3.3 V ±5%, 1.8 V ±5%, TA = –40 to 85 °C)
Parameter
Symbol
Test Condition
Min
Typ
Max
Units
Si5341 Status Output Pins (LOL, INTR), SDA/SDIO2, SDO
Output Voltage
VOH
IOH = –2 mA
VDDIO1 x 0.75
—
—
V
VOL
IOL = 2 mA
—
—
VDDIO1 x 0.15
V
—
—
V
—
1
V
Si5340 Status Output Pins (INTR), LOL, LOS_XAXB, SDA/SDIO2, SDO
Output Voltage
VOH
VOL
IOH = –2 mA
IOL = 2 mA
VDDIO1 x 0.75
—
VDDIO x 0.15
Notes:
1. VDDIO is determined by the IO_VDD_SEL bit. It is selectable as VDDA or VDD. Refer to the Reference Manual for more
details on register settings.
2. The VOH specification does not apply to the open-drain SDA/SDIO output when the serial interface is in I2C mode or is
unused with I2C_SEL pulled high. VOL remains valid in all cases.
Rev. 1.0
11
Si5341/40
Table 7. LVCMOS Clock Output Specifications
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%, VDDO = 1.8 V ±5%, 2.5 V ±5%, or 3.3 V ±5%, TA = –40 to 85 °C)
Parameter
Symbol
Test Condition
Min
Typ
Max
Units
0.0001
—
250
MHz
fOUT < 100 MHz
47
—
53
%
100 MHz < fOUT < 250 MHz
44
—
55
—
—
100
ps
VDDO x
0.75
—
—
V
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Output Frequency
Duty Cycle
DC
Output-to-Output Skew
TSK
Output Voltage High1, 2, 3
VOH
VDDO = 3.3 V
OUTx_CMOS_DRV=1
IOH = –10 mA
OUTx_CMOS_DRV=2
IOH = –12 mA
OUTx_CMOS_DRV=3
IOH = –17 mA
VDDO = 2.5 V
OUTx_CMOS_DRV=1
IOH = –6 mA
OUTx_CMOS_DRV=2
IOH = –8 mA
OUTx_CMOS_DRV=3
IOH = –11 mA
VDDO x
0.75
V
VDDO = 1.8 V
OUTx_CMOS_DRV=2
IOH = –4 mA
OUTx_CMOS_DRV=3
IOH = –5 mA
VDDO x
0.75
V
Notes:
1. Driver strength is a register programmable setting and stored in NVM. Options are OUTx_CMOS_DRV = 1, 2, 3. Refer
to the Reference Manual for more details on register settings.
2. IOL/IOH is measured at VOL/VOH as shown in the dc test configuration.
3. A series termination resistor (Rs) is recommended to help match the source impedance to a 50  PCB trace. A 5 pF
capacitive load is assumed. The LVCMOS outputs were set to OUTx_CMOS_DRV = 3.
DC Test Configuration
AC Test Configuration
Trace length 5 inches
IOL/IOH
499 
IDDO
4.7 pF
OUT
Zs
0.1 uF
50 
OUT
VOL/VOH
499 
0.1 uF
50 
4.7 pF
12
Rev. 1.0
50 probe, scope
56 
56 
50 probe, scope
Si5341/40
Table 7. LVCMOS Clock Output Specifications (Continued)
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%, VDDO = 1.8 V ±5%, 2.5 V ±5%, or 3.3 V ±5%, TA = –40 to 85 °C)
Parameter
Symbol
Output Voltage Low1, 2, 3
VOL
Test Condition
Min
Typ
Max
Units
VDDO
x 0.15
V
VDDO
x 0.15
V
VDDO
x 0.15
V
VDDO = 3.3 V
OUTx_CMOS_DRV=1
IOL = 10 mA
—
—
OUTx_CMOS_DRV=2
IOL = 12 mA
—
—
OUTx_CMOS_DRV=3
IOL = 17 mA
—
—
VDDO = 2.5 V
OUTx_CMOS_DRV=1
IOL = 6 mA
—
—
OUTx_CMOS_DRV=2
IOL = 8 mA
—
—
OUTx_CMOS_DRV=3
IOL = 11 mA
—
—
VDDO = 1.8 V
LVCMOS Rise and Fall
Times3
(20% to 80%)
OUTx_CMOS_DRV=2
IOL = 4 mA
—
—
OUTx_CMOS_DRV=3
IOL = 5 mA
—
—
VDDO = 3.3V
—
420
550
ps
VDDO = 2.5 V
—
475
625
ps
VDDO = 1.8 V
—
525
705
ps
tr/tf
Notes:
1. Driver strength is a register programmable setting and stored in NVM. Options are OUTx_CMOS_DRV = 1, 2, 3. Refer
to the Reference Manual for more details on register settings.
2. IOL/IOH is measured at VOL/VOH as shown in the dc test configuration.
3. A series termination resistor (Rs) is recommended to help match the source impedance to a 50  PCB trace. A 5 pF
capacitive load is assumed. The LVCMOS outputs were set to OUTx_CMOS_DRV = 3.
DC Test Configuration
AC Test Configuration
Trace length 5 inches
IOL/IOH
499 
IDDO
4.7 pF
OUT
Zs
0.1 uF
50 
OUT
VOL/VOH
499 
56 
0.1 uF
50 
4.7 pF
Rev. 1.0
50 probe, scope
50 probe, scope
56 
13
Si5341/40
Table 8. Performance Characteristics
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%, TA = –40 to 85 °C)
Parameter
Min
Typ
Max
Units
FVCO
13.5
—
14.256
GHz
PLL Loop Bandwidth
fBW
—
1.0
—
MHz
Initial Start-Up Time
tSTART
—
30
45
ms
—
—
15
ms
VCO Frequency Range
Symbol
Test Condition
Time from power-up to when the
device generates clocks (Input
Frequency > 48 MHz)
POR1 to Serial Interface
Ready
tRDY
PLL Lock Time6
tACQ
fIN = 19.44 MHz
22
—
180
ms
tDELAY_-
fVCO = 14 GHz
Delay is controlled by the MultiSynth
—
0.28
—
ps
—
71.4
—
ps
—
±9.14
—
ns
Integer Mode3
12 kHz to 20 MHz
—
0.135
0.175
ps RMS
Fractional/DCO Mode4
12 kHz to 20 MHz
—
0.160
0.205
ps RMS
Derived from
integrated phase noise
—
0.140
—
ps pk-pk
—
0.250
—
ps pk
N = 10,000 cycles
Integer or Fractional Mode3,4.
Measured in the time domain.
Performance is limited by the
noise floor of the
equipment.
—
7.3
—
ps pk-pk
—
8.1
—
ps pk
Output Delay Adjustment
frac
tDELAY_int
tRANGE
Jitter Generation
Locked to External Clock2
JGEN
JPER
JCC
JPER
JCC
Notes:
1. Measured as time from valid VDD and VDD33 rails (90% of their value) to when the serial interface is ready to respond
to commands. Measured in SPI 4-wire mode, with SCLK @ 10 MHz.
2. Jitter generation test conditions fIN = 100 MHz, fOUT = 156.25 MHz LVPECL.
3. Integer mode assumes that the output dividers (Nn/Nd) are configured with an integer value.
4. Fractional and DCO modes assume that the output dividers (Nn/Nd) are configured with a fractional value and the
feedback divider is integer.
5. Initiate a soft reset command to align the outputs to within +/- 100 ps.
6. PLL lock time is measured by first letting the PLL lock, then turning off the input clock, and then turning on the input
clock. The time from the first edge of the input clock being re-applied until LOL de-asserts is the PLL lock time.
14
Rev. 1.0
Si5341/40
Table 8. Performance Characteristics (Continued)
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%, TA = –40 to 85 °C)
Parameter
Jitter Generation
Locked to External XTAL
Symbol
Test Condition
Min
Typ
Max
Units
XTAL Frequency = 48 MHz
JGEN
JPER
JCC
JPER
JCC
Integer Mode3
12 kHz to 20 MHz
—
0.090
0.150
ps RMS
Fractional/DCO Mode4
12 kHz to 20 MHz
—
0.120
0.165
ps RMS
Derived from
integrated phase noise
—
0.150
—
ps pk-pk
—
0.270
—
ps pk
N = 10, 000 cycles
Integer or Fractional Mode3,4 .
Measured in the time domain.
Performance is limited by the
noise floor of the equipment.
—
7.3
—
ps pk-pk
—
7.8
—
ps pk
Integer Mode
12 kHz to 20 MHz
0.125
0.330
ps RMS
Fractional
12 kHz to 20 MHz
0.170
0.360
ps RMS
XTAL Frequency = 25 MHz
JGEN
Notes:
1. Measured as time from valid VDD and VDD33 rails (90% of their value) to when the serial interface is ready to respond
to commands. Measured in SPI 4-wire mode, with SCLK @ 10 MHz.
2. Jitter generation test conditions fIN = 100 MHz, fOUT = 156.25 MHz LVPECL.
3. Integer mode assumes that the output dividers (Nn/Nd) are configured with an integer value.
4. Fractional and DCO modes assume that the output dividers (Nn/Nd) are configured with a fractional value and the
feedback divider is integer.
5. Initiate a soft reset command to align the outputs to within +/- 100 ps.
6. PLL lock time is measured by first letting the PLL lock, then turning off the input clock, and then turning on the input
clock. The time from the first edge of the input clock being re-applied until LOL de-asserts is the PLL lock time.
Rev. 1.0
15
Si5341/40
Table 9. I2C Timing Specifications (SCL,SDA)
Parameter
Symbol
Test Condition
Min
Max
Min
Standard Mode
100 kbps
SCL Clock
Frequency
Max
Units
Fast Mode
400 kbps
fSCL
—
100
—
400
kHz
Hold Time
(Repeated)
START Condition
tHD:STA
4.0
—
0.6
—
µs
Low Period of the
SCL Clock
tLOW
4.7
—
1.3
—
µs
HIGH Period of
the SCL Clock
tHIGH
4.0
—
0.6
—
µs
Set-up Time for a
Repeated START
Condition
tSU:STA
4.7
—
0.6
—
µs
Data Hold Time
tHD:DAT
100
—
100
—
ns
Data Set-up Time
tSU:DAT
250
—
100
—
ns
Rise Time of Both
SDA and SCL
Signals
tr
—
1000
20
300
ns
Fall Time of Both
SDA and SCL
Signals
tf
—
300
—
300
ns
Set-up Time for
STOP Condition
tSU:STO
4.0
—
0.6
—
µs
Bus Free Time
between a STOP
and START Condition
tBUF
4.7
—
1.3
—
µs
Data Valid Time
tVD:DAT
—
3.45
—
0.9
µs
Data Valid
Acknowledge
Time
tVD:ACK
—
3.45
—
0.9
µs
16
Rev. 1.0
Si5341/40
Figure 2. I2C Serial Port Timing Standard and Fast Modes
Rev. 1.0
17
Si5341/40
Table 10. SPI Timing Specifications (4-Wire)
(VDD = 1.8 V ±5%, VDDA = 3.3V ±5%, TA = –40 to 85 °C)
Parameter
Symbol
Min
Typ
Max
Units
SCLK Frequency
fSPI
—
—
20
MHz
SCLK Duty Cycle
TDC
40
—
60
%
SCLK Period
TC
50
—
—
ns
Delay Time, SCLK Fall to SDO Active
TD1
—
12.5
18
ns
Delay Time, SCLK Fall to SDO
TD2
—
10
15
ns
Delay Time, CS Rise to SDO Tri-State
TD3
—
10
15
ns
Setup Time, CS to SCLK
TSU1
5
—
—
ns
Hold Time, CS to SCLK Rise
TH1
5
—
—
ns
Setup Time, SDI to SCLK Rise
TSU2
5
—
—
ns
Hold Time, SDI to SCLK Rise
TH2
5
—
—
ns
Delay Time Between Chip Selects (CS)
TCS
2
—
—
TC
TSU1
TD1
TC
SCLK
TH1
CS
TSU2
TH2
TCS
SDI
TD2
TD3
SDO
Figure 3. 4-Wire SPI Serial Interface Timing
18
Rev. 1.0
Si5341/40
Table 11. SPI Timing Specifications (3-Wire)
(VDD = 1.8 V ±5%, VDDA = 3.3 V ±5%, TA = –40 to 85 °C)
Parameter
Symbol
Min
Typ
Max
Units
SCLK Frequency
fSPI
—
—
20
MHz
SCLK Duty Cycle
TDC
40
—
60
%
SCLK Period
TC
50
—
—
ns
Delay Time, SCLK Fall to SDIO Turn-on
TD1
—
12.5
20
ns
Delay Time, SCLK Fall to SDIO Next-bit
TD2
—
10
15
ns
Delay Time, CS Rise to SDIO Tri-State
TD3
—
10
15
ns
Setup Time, CS to SCLK
TSU1
5
—
—
ns
Hold Time, CS to SCLK Rise
TH1
5
—
—
ns
Setup Time, SDI to SCLK Rise
TSU2
5
—
—
ns
Hold Time, SDI to SCLK Rise
TH2
5
—
—
ns
Delay Time Between Chip Selects (CS)
TCS
2
—
—
TC
TSU1
TC
SCLK
TD1
CS
TSU2
TH1
TD2
TH2
TCS
SDIO
TD3
Figure 4. 3-Wire SPI Serial Interface Timing
Rev. 1.0
19
Si5341/40
Table 12. Crystal Specifications
Parameter
Crystal Frequency Range
Symbol
Test Condition
Min
Typ
Max
Units
fXTAL_48-54
Frequency range for
best jitter performance
48
—
54
MHz
Load Capacitance
CL_48-54
—
8
—
pF
Shunt Capacitance
CO_48-54
—
—
2
pF
Crystal Drive Level
dL_48-54
—
—
200
µW
Equivalent Series Resistance
rESR_48-54 Refer to the Si5341/40 Family Reference Manual to determine ESR.
fXTAL_25
—
25
—
MHz
Load Capacitance
CL_25
—
8
—
pF
Shunt Capacitance
CO_25
—
—
3
pF
Crystal Drive Level
dL_25
—
—
200
µW
Crystal Frequency Range
Equivalent Series Resistance
rESR_25
Refer to the Si5341/40 Family Reference Manual to determine ESR
Notes:
1. The Si5341/40 is designed to work with crystals that meet the specifications in Table 12.
2. Refer to the Si5341/40 Family Reference Manual for recommended 48 to 54 MHz crystals.
20
Rev. 1.0
Si5341/40
Table 13. Thermal Characteristics
Parameter
Symbol
Test Condition*
Value
Units
JA
Still Air
22
°C/W
Air Flow 1 m/s
19.4
Air Flow 2 m/s
18.3
Si5341 — 64QFN
Thermal Resistance
Junction to Ambient
Thermal Resistance
Junction to Case
JC
9.5
Thermal Resistance
Junction to Board
JB
9.4
JB
9.3
JT
0.2
Thermal Resistance
Junction to Top Center
Si5340–44QFN
Thermal Resistance
Junction to Ambient
JA
Still Air
22.3
Air Flow 1 m/s
19.4
Air Flow 2 m/s
18.4
Thermal Resistance
Junction to Case
JC
10.9
Thermal Resistance
Junction to Board
JB
9.3
JB
9.2
JT
0.23
Thermal Resistance
Junction to Top Center
°C/W
*Note: Based on PCB Dimension: 3” x 4.5”, PCB Thickness: 1.6 mm, PCB Land/Via under GND pad: 36, Number of Cu
Layers: 4
Rev. 1.0
21
Si5341/40
Table 14. Absolute Maximum Ratings1,2,3,4
Parameter
Symbol
Test Condition
Value
Units
Storage Temperature Range
TSTG
–55 to +150
°C
DC Supply Voltage
VDD
–0.5 to 3.8
V
VDDA
–0.5 to 3.8
V
VDDO
–0.5 to 3.8
V
Input Voltage Range
Latch-up Tolerance
VI1
IN0-IN2, FB_IN
–0.85 to 3.8
V
VI2
IN_SEL[1:0],
RST,
OE,
SYNC,
I2C_SEL,
SDI,
SCLK,
A0/CS
A1,
SDA/SDIO
FINC/FDEC
–0.5 to 3.8
V
VI3
XA/XB
–0.5 to 2.7
V
LU
ESD Tolerance
HBM
Junction Temperature
Soldering Temperature
(Pb-free profile)4
Soldering Temperature Time at TPEAK
(Pb-free profile)4
JESD78 Compliant
100 pF, 1.5 k
2.0
kV
TJCT
–55 to 150
°C
TPEAK
260
°C
TP
20-40
sec
Notes:
1. 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.
2. 64-QFN and 44-QFN packages are RoHS-6 compliant.
3. For MSL and more packaging information, go to www.silabs.com/support/quality/pages/rohsinformation.aspx.
4. The device is compliant with JEDEC J-STD-020.
22
Rev. 1.0
Si5341/40
3. Typical Operating Characteristics
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Figure 5. Integer Mode—48 MHz Crystal, 625 MHz Output (2.5 V LVDS)
Rev. 1.0
23
Si5341/40
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Figure 6. Integer Mode—48 MHz Crystal, 156.25 MHz Output (2.5 V LVDS)
24
Rev. 1.0
Si5341/40
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Figure 7. Fractional Mode—48 MHz Crystal, 155.52 MHz Output (2.5 V LVDS)
Rev. 1.0
25
Si5341/40
VDDA
VDD
4. Detailed Block Diagrams
3
Si5341
IN_SEL[1:0]
Clock
Generator
÷P0
IN2
PD
÷P2
IN2
LPF
÷
MultiSynth
OSC
N
÷ 0n
N0d
t0
N1n
N1d
t1
N2n
N2d
t2
N
÷ 3n
N3d
t3
N4n
N4d
t4
XA
÷
Zero Delay
Mode
FB_IN
÷
÷Pfb
FB_IN
I2C_SEL
RST
A0/CS
NVM
Status
Monitors
Figure 8. Si5341 Block Diagram
26
÷R2
VDDO2
OUT2
OUT2
÷R3
VDDO3
OUT3
OUT3
÷R4
VDDO4
OUT4
OUT4
÷R5
VDDO5
OUT5
OUT5
÷R6
VDDO6
OUT6
OUT6
÷R7
VDDO7
OUT7
OUT7
÷R8
VDDO8
OUT8
OUT8
÷R9
VDDO9
OUT9
OUT9
Frequency
Control
FINC
SCLK
SPI/
I2C
INTR
A1/SDO
÷
LOL
SDA/SDIO
Mn
Md
÷ PXAXB
XB
25MHz,
48-54MHz
XTAL
÷R1
VDDO1
OUT1
OUT1
PLL
÷P1
IN1
VDDO0
OUT0
OUT0
Rev. 1.0
OE
IN1
FDEC
IN0
÷R0
SYNC
IN0
Dividers/
Drivers
4
VDDA
VDD
Si5341/40
2
Si5340
Clock
Generator
÷PXAXB
XB
25MHz,
48-54MHz
XTAL
OSC
PLL
IN0
IN0
IN1
IN1
IN2
IN2
Dividers/
Drivers
MultiSynth
XA
÷P0
LPF
÷P1
PD
Md
÷
Mn
÷P2
÷
Nn0
Nd0
t0
÷R0
VDDO0
OUT0
OUT0
÷
Nn1
Nd1
t1
÷R1
VDDO1
OUT1
OUT1
÷
N2n
N2d
t2
÷R2
VDDO2
OUT2
OUT2
÷
N3n
N3d
t3
÷R3
VDDO3
OUT3
OUT3
IN_SEL[1:0]
Zero Delay
Mode
OE
SCLK
NVM
A0/CS
A1/SDO
I2C_SEL
LOSXAB
SDA/SDIO
SPI/
I2C
Status
Monitors
LOL
÷Pfb
INTR
FB_IN
RST
FB_IN
Figure 9. Si5340 Detailed Block Diagram
Rev. 1.0
27
Si5341/40
5. Functional Description
The Si5341/40 combines a wide band PLL with next generation MultiSynth technology to offer the industry’s most
versatile and high performance clock generator. The PLL locks to either an external crystal between XA/XB or to
an external clock connected to XA/XB or IN0,1,2. A fractional or integer multiplier takes the selected input clock or
crystal frequency up to a very high frequency that is then divided by the MultiSynth output stage to any frequency in
the range of 100 Hz to 712.5 MHz on each output. The MultiSynth stage can divide by both integer and fractional
values.The high-resolution fractional MultiSynth dividers enables true any-frequency input to any-frequency on any
of the outputs. The output drivers offer flexible output formats which are independently configurable on each of the
outputs. This clock generator is fully configurable via its serial interface (I2C/SPI) and includes in-circuit
programmable non-volatile memory.
5.1. Power-up and Initialization
Once power is applied, the device begins an initialization period where it downloads default register values and
configuration data from NVM and performs other initialization tasks. Communicating with the device through the
serial interface is possible once this initialization period is complete. No clocks will be generated until the
initialization is done. There are two types of resets available. A hard reset is functionally similar to a device powerup. All registers will be restored to the values stored in NVM, and all circuits will be restored to their initial state
including the serial interface. A hard reset is initiated using the RST pin or by asserting the hard reset bit. A soft
reset bypasses the NVM download. It is simply used to initiate register configuration changes.
Power-Up
Hard Reset
bit asserted
RST
pin asserted
NVM download
Soft Reset
bit asserted
Initialization
Serial interface
ready
Figure 10. Si5341 Power-up and Initialization
28
Rev. 1.0
Si5341/40
5.2. Frequency Configuration
The phase-locked loop is fully contained and does not require external loop filter components to operate. Its
function is to phase lock to the selected input and provide a common reference to the MultiSynth high-performance
fractional dividers.
A crosspoint mux connects any of the MultiSynth divided frequencies to any of the outputs drivers. Additional
output integer dividers provide further frequency division by an even integer from 2 to (2^25)-2. The frequency
configuration of the device is programmed by setting the input dividers (P), the PLL feedback fractional divider (Mn/
Md), the MultiSynth fractional dividers (Nn/Nd), and the output integer dividers (R). Silicon Labs’ Clockbuilder Pro
configuration utility determines the optimum divider values for any desired input and output frequency plan.
5.3. Inputs
The Si5341/40 requires either an external crystal at its XA/XB pins or an external clock at XA/XB or IN0,1,2.
5.3.1. XA/XB Clock and Crystal Input
An internal crystal oscillator exists between pin XA and XB. When this oscillator is enabled, an external crystal
connected across these pins will oscillate and provide a clock input to the PLL. A crystal frequency of 25 MHz can
be used although crystals in the frequency range of 48 MHz to 54 MHz are recommended for best jitter
performance. Frequency offsets due to CL mismatch can be adjusted using the frequency adjustment feature
which allows frequency adjustments of ±1000 ppm. The Si5341/40 Family Reference Manual provides additional
information on PCB layout recommendations for the crystal to ensure optimum jitter performance. Refer to
Table 12 for crystal specifications.
The Si5341/40 can also accommodate an external input clock instead of a crystal. This allows the use of crystal
oscillator (XO) instead of a XTAL. Selection between the external XTAL or input clock is controlled by register
configuration. The internal crystal load capacitors (CL) are disabled in the input clock mode. Refer to Table 3 for the
input clock requirements at XAXB. Both a single-ended or a differential input clock can be connected to the XA/XB
pins as shown in Figure 11. A PXAXB divider is available to accommodate external clock frequencies higher than
54 MHz.
Rev. 1.0
29
Si5341/40
DifferentialConnection
Single‐ended XO Connection
nc X1
nc X2
nc X1
nc X2
Note: 2.0 Vpp_se max
0.1 uf
100
2xCL
0.1 uf
XA
2xCL
XA
100
OSC
OSC
XB
XO with Clipped Sine Wave 0.1 uf XB
Output
2xCL
Si5341/40
0.1 uf
2xCL
Si5341/40
Note: 2.5 Vpp diff max
Crystal Connection
Single‐ended Connection
nc X1
nc X2
Note: 2.0 Vpp_se max
X1
2xC L
CMOS Output
0.1 uf
R1
XA
OSC
XO VDD
3.3 V
2.5 V
1.8 V
R1
523 
475 
158 
R2
442 
649 
866 
2xCL
XA
R2
0.1 uf
0.1 uf
XTAL
OSC
XB
XB
2xCL
Si5341/40
X2
2xC L
Si5341/40
Figure 11. XAXB External Crystal and Clock Connections
5.3.2. Input Clocks (IN0, IN1, IN2)
A differential or single-ended clock can be applied at IN2, IN1, or IN0. The recommended input termination
schemes are shown in Figure 12.
AC Coupled Differential
0.1 uf
50
Si5341/40
50
0.1 uf
Differential
Driver LVDS,
LVPECL, CML
INx
50
50
INx
0.1 uf
AC Coupled LVCMOS or Single Ended
50
3.3V, 2.5V, 1.8V
LVCMOS or Single
Ended Signal
Si5341/40
0.1 uf
INx
0.1 uf
INx
Figure 12. Termination of Differential and LVCMOS Input Signals
30
Rev. 1.0
Si5341/40
5.3.3. Input Selection (IN0, IN1, IN2, XA/XB)
The active clock input is selected using the IN_SEL[1:0] pins or by register control. A register bit determines input
selection as pin or register selectable. There are internal pull ups on the IN_SEL pins.
Table 15. Manual Input Selection Using IN_SEL[1:0] Pins
IN_SEL[1:0]
Selected Input
0
0
IN0
0
1
IN1
1
0
IN2
1
1
XA/XB
5.4. Fault Monitoring
The Si5341/40 provides fault indicators which monitor loss of signal (LOS) of the inputs (IN0, IN1, IN2, XA/XB,
FB_IN) and loss of lock (LOL) for the PLL. This is shown in Figure 13.
IN0
IN0
IN1
IN1
IN2
÷P0
LOS0
÷P1
LOS1
÷P2
IN2
Si5341/40
LOL
PLL
PD
LOS2
LPF
÷
Mn
Md
LOSXAB
÷Pfb
INTR
LOL
LOSFB
LOS0
FB_IN
LOSXAB
FB_IN
OSC
LOS2
XB
LOS1
XA
Figure 13. LOS and LOL Fault Monitors
5.4.1. Status Indicators
The state of the status monitors are accessible by reading registers through the serial interface or with dedicated
pin (LOL). Each of the status indicator register bits has a corresponding sticky bit in a separate register location.
Once a status bit is asserted its corresponding sticky bit (_FLG) will remain asserted until cleared. Writing a logic
zero to a sticky register bit clears its state.
5.4.2. Interrupt Pin (INTR)
An interrupt pin (INTR) indicates a change in state with any of the status registers. All status registers are maskable
to prevent assertion of the interrupt pin. The state of the INTR pin is reset by clearing the status registers.
Rev. 1.0
31
Si5341/40
5.5. Outputs
The Si5341 supports 10 differential output drivers which can be independently configured as differential or
LVCMOS. The Si5340 supports 4 output drivers independently configurable as differential or LVCMOS.
5.5.1. Output Signal Format
The differential output amplitude and common mode voltage are both fully programmable and compatible with a
wide variety of signal formats including LVDS and LVPECL. In addition to supporting differential signals, any of the
outputs can be configured as LVCMOS (3.3 V, 2.5 V, or 1.8 V) drivers providing up to 20 single-ended outputs, or
any combination of differential and single-ended outputs.
5.5.2. Differential Output Terminations
The differential output drivers support both ac-coupled and dc-coupled terminations as shown in Figure 14.
AC Coupled LVDS/LVPECL
DC Coupled LVDS
VDDO = 3.3V, 2.5V, 1.8V
VDDO = 3.3V, 2.5V, 1.8V
50
OUTx
50
OUTx
100
OUTx
100
OUTx
50
50
Internally
self-biased
Si5341/40
Si5341/40
AC Coupled LVPECL/CML
DC Coupled LVCMOS
3.3V, 2.5V, 1.8V
LVCMOS
VDDO = 3.3V, 2.5V, 1.8V
VDD – 1.3V
VDDO = 3.3V, 2.5V
50
50
OUTx
Rs
OUTx
OUTx
50
50
Si5341/40
Si5341/40
Rs
AC Coupled HCSL
VDDRX
VDDO = 3.3V, 2.5V, 1.8V
R1
OUTx
R1
50
Standard
HCSL
Receiver
OUTx
50
Si5341/40
R2
R2
1 V
For VOption
CM = 0.37
VDDRX
3.3 V
2.5 V
1.8 V
R1
R2
442 Ohms 56.2 Ohms
332 Ohms 59 Ohms
243 Ohms 63.4 Ohms
Figure 14. Supported Differential Output Terminations
32
50
OUTx
Rev. 1.0
50
Si5341/40
5.5.3. Differential Output Modes
There are two selectable* differential output modes: Normal and Low Power. Each output can support a unique
mode. In this document, the terms, LVDS and LVPECL, refer to driver formats that are compatible with these
signaling standards.
 Differential Normal Mode: When an output driver is configured in normal mode, its output amplitude is
selectable as one of 7 settings ranging from ~130 mVpp_se to ~920 mVpp_se in increments of ~100 mV. See
Appendix A for additional information. The output impedance in the normal mode is 100 differentialAny of
the terminations shown in Figure 14 are supported in this mode.
 Differential Low Power Mode: When an output driver is configured in low power mode, its output amplitude is
configurable as one of 7 settings ranging from ~200 mVpp_se to ~1600 mVpp_se in increments of ~200 mV.
When in Differential Low Power Mode, the output impedance of the driver is much greater than 100 however
the signal integrity will still be optimum as long as the differential clock traces are properly terminated in their
characteristic impedance. Any of the terminations shown in Figure 14 are supported in this mode.
*Note: Not all amplitude levels are available for selection in the CBPro device configuration Wizard. Refer to Sections 5.9 and
5.10 for more information. See also Appendix A of the Si5341/40 Reference Manual.
5.5.4. Programmable Common Mode Voltage For Differential Outputs
The common mode voltage (VCM) for the differential Normal and Low Power modes are programmable so that
LVDS specifications can be met and for the best signal integrity with different supply voltages. When dc coupling
the output driver it is essential that the receiver should have a relatively high common mode impedance so that the
common mode current from the output driver is very small.
5.5.5. LVCMOS Output Terminations
LVCMOS outputs are typically dc-coupled as shown in Figure 15.
DC Coupled LVCMOS
3.3V, 2.5V, 1.8V
LVCMOS
VDDO = 3.3V, 2.5V, 1.8V
50
OUTx
Rs
OUTx
50
Rs
Figure 15. LVCMOS Output Terminations
Rev. 1.0
33
Si5341/40
5.5.6. LVCMOS Output Impedance And Drive Strength Selection
Each LVCMOS driver has a configurable output impedance. It is highly recommended that the minimum output
impedance (strongest drive setting) is selected and a suitable series resistor (Rs) is chosen to match the trace
impedance.
Table 16. Nominal Output Impedance vs OUTx_CMOS_DRV (register)
CMOS_DRIVE_Selection
VDDO
OUTx_CMOS_DRV=1
OUTx_CMOS_DRV=2
OUTx_CMOS_DRV=3
3.3 V
38 
30 
22 
2.5 V
43 
35 
24 
1.8 V
—
46 
31 
*Note: Refer to the Si5341/40 Family Reference Manual for more information on register settings.
5.5.7. LVCMOS Output Signal Swing
The signal swing (VOL/VOH) of the LVCMOS output drivers is set by the voltage on the VDDO pins. Each output
driver has its own VDDO pin allowing a unique output voltage swing for each of the LVCMOS drivers.
5.5.8. LVCMOS Output Polarity
When a driver is configured as an LVCMOS output it generates a clock signal on both pins (OUTx and OUTx). By
default the clock on the OUTx pin is generated with complementary polarity with the clock on the OUTx pin. The
LVCMOS OUTx and OUTx outputs can also be generated in phase.
5.5.9. Output Enable/Disable
The OE pin provides a convenient method of disabling or enabling the output drivers. When the OE pin is held high
all outputs will be disabled. When held low, the outputs will be enabled. Outputs in the enabled state can be
individually disabled through register control.
5.5.10. Output Driver State When Disabled
The disabled state of an output driver is configurable as: disable low or disable high.
5.5.11. Synchronous/Asynchronous Output Disable Feature
Outputs can be configured to disable synchronously or asynchronously. The default state is synchronous output
disable. In synchronous disable mode the output will wait until a clock period has completed before the driver is
disabled. This prevents unwanted runt pulses from occurring when disabling an output. In asynchronous disable
mode the output clock will disable immediately without waiting for the period to complete.
34
Rev. 1.0
Si5341/40
5.5.12. Output Delay Control (t0 – t4)
The Si5341/40 uses independent MultiSynth dividers (N0 - N4) to generate up to 5 unique frequencies to its 10
outputs through a crosspoint switch. By default all clocks are phase aligned. A delay path (t0 - t4) associated with
each of these dividers is available for applications that need a specific output skew configuration. Each delay path
is controlled by a register parameter call Nx_DELAY with a resolution of ~0.28 ps over a range of ~±9.14 ns. This is
useful for PCB trace length mismatch compensation. After the delay controls are configured, the soft reset bit
SOFT_RST must be set high so that the output delay takes effect and the outputs are re-aligned.
÷N0
t0
÷R0
VDDO0
OUT0
OUT0
VDDO1
OUT1
OUT1
÷N1
t1
÷R1
÷N2
t2
÷R2
VDDO2
OUT2
OUT2
÷N3
t3
÷R3
VDDO3
OUT3
OUT3
÷N4
t4
÷R4
VDDO4
OUT4
OUT4
÷R5
VDDO5
OUT5
OUT5
÷R6
VDDO6
OUT6
OUT6
÷R7
VDDO7
OUT7
OUT7
÷R8
VDDO8
OUT8
OUT8
÷R9
VDDO9
OUT9
OUT9
Figure 16. Example of Independently Configurable Path Delays
All delay values are restored to their NVM programmed values after power-up or after a hard reset. Delay default
values can be written to the NVM allowing a custom delay offset configuration at power-up or after a hardware
reset.
Rev. 1.0
35
Si5341/40
5.5.13. Zero Delay Mode
A zero delay mode is available for applications that require fixed and consistent minimum delay between the
selected input and outputs. The zero delay mode is configured by opening the internal feedback loop through
software configuration and closing the loop externally as shown in Figure 17. This helps to cancel out the internal
delay introduced by the dividers, the crosspoint, the input, and the output drivers. Any one of the outputs can be fed
back to the FB_IN pins, although using the output driver that achieves the shortest trace length will help to
minimize the input-to-output delay. It is recommended to connect OUT9 (Si5341) or OUT3 (Si5340) to FB_IN for
external feedback. The FB_IN input pins must be terminated and ac-coupled when zero delay mode is used. A
differential external feedback path connection is necessary for best performance.
Si5341
IN0
IN0
fIN
IN1
IN1
IN2
IN2
VDDO0
OUT0
OUT0
VDDO1
OUT1
OUT1
÷ P0
VDDO2
OUT2
OUT2
÷ P1
÷ P2
VDDO3
OUT3
OUT3
IN_SEL[1:0]
FB_IN
Zero Delay
Mode
100
÷Pfb
fFB = fIN
PD
VDDO7
OUT7
OUT7
LPF
÷
FB_IN
MultiSynth
& Dividers
PLL
Mn
Md
VDDO8
OUT8
OUT8
÷
N9n
N9d
÷R9
VDDO9
OUT9
OUT9
External Feedback Path
Figure 17. Si5341 Zero Delay Mode Setup
5.5.14. Sync Pin (Synchronizing R Dividers)
All the output R dividers are reset to the default NVM register state after a power-up or a hard reset. This ensures
consistent and repeatable phase alignment across all output drivers to within ±100 ps of the expected value from
the NVM download. Resetting the device using the RST pin or asserting the hard reset bit will have the same
result. The SYNC pin provides another method of re-aligning the R dividers without resetting the device, however,
the outputs will only align to within 50 ns when using the SYNC pin. This pin is positive edge triggered. Asserting
the sync register bit provides the same function as the SYNC pin. A soft reset will align the outputs to within
±100 ps of the expected value based upon the Nx_DELAY parameter.
5.5.15. Output Crosspoint
The output crosspoint allows any of the N dividers to connect to any of the clock outputs.
36
Rev. 1.0
Si5341/40
5.5.16. Digitally Controlled Oscillator (DCO) Modes
Each MultiSynth can be digitally controlled to so that all outputs connected to the MultiSynth change frequency in
real time without any transition glitches. There are two ways to control the MultiSynth to accomplish this task:
Use
the Frequency Increment/Decrement Pins or register bits
Write directly to the numerator of the MultiSynth divider.
An output that is controlled as a DCO is useful for simple tasks such as frequency margining or CPU speed control.
The output can also be used for more sophisticated tasks such as FIFO management by adjusting the frequency of
the read or write clock to the FIFO or using the output as a variable Local Oscillator in a radio application.
5.5.16.1. DCO with Frequency Increment/Decrement Pins/Bits
Each of the MultiSynth fractional dividers can be independently stepped up or down in predefined steps with a
resolution as low as 0.001 ppb. Setting of the step size and control of the frequency increment or decrement is
accomplished by setting the step size with the 44 bit Frequency Step Word (FSTEPW). When the FINC or FDEC
pin or register bit is asserted the output frequency will increment or decrement respectivley by the amount specified
in the FSTEPW.
5.5.16.2. DCO with Direct Register Writes
When a MultiSynth numerator and its corresponding update bit is written, the new numerator value will take effect
and the output frequency will change without any glitches. The MultiSynth numerator and denominator terms can
be left and right shifted so that the least significant bit of the numerator word represents the exact step resolution
that is needed for your application.
5.6. Power Management
Several unused functions can be powered down to minimize power consumption. Consult the Si5341/40 Family
Reference Manual and ClockBuilder Pro configuration utility for details.
5.7. In-Circuit Programming
The Si5341/40 is fully configurable using the serial interface (I2C or SPI). At power-up the device downloads its
default register values from internal non-volatile memory (NVM). Application specific default configurations can be
written into NVM allowing the device to generate specific clock frequencies at power-up. Writing default values to
NVM is in-circuit programmable with normal operating power supply voltages applied to its VDD and VDDA pins. The
NVM is two time writable. Once a new configuration has been written to NVM, the old configuration is no longer
accessible. Refer to the Si5341/40 Family Reference Manual for a detailed procedure for writing registers to NVM.
5.8. Serial Interface
Configuration and operation of the Si5341/40 is controlled by reading and writing registers using the I2C or SPI
interface. The I2C_SEL pin selects I2C or SPI operation. Communication with both 3.3V and 1.8V host is
supported. The SPI mode operates in either 4-wire or 3-wire. See the Si5341/40 Family Reference Manual for
details.
5.9. Custom Factory Preprogrammed Devices
For applications where a serial interface is not available for programming the device, custom pre-programmed
parts can be ordered with a specific configuration written into NVM. A factory pre-programmed device will generate
clocks at power-up. Custom, factory-preprogrammed devices are available. Use the ClockBuilder Pro custom part
number wizard (www.silabs.com/clockbuilderpro) to quickly and easily request and generate a custom part number
for your configuration. In less than three minutes, you will be able to generate a custom part number with a detailed
data sheet addendum matching your design’s configuration. Once you receive the confirmation email with the data
sheet addendum, simply place an order with your local Silicon Labs sales representative. Samples of your preprogrammed device will ship to you typically within two weeks.
Rev. 1.0
37
Si5341/40
5.10. Enabling Features and/or Configuration Settings Not Available in ClockBuilder Pro
for Factory Pre-programmed Devices
As with essentially all software utilities, ClockBuilder Pro is continuously updated and enhanced. By registering at
www.silabs.com and opting in for updates to software, you will be notified whenever changes are made and what
the impact of those changes are. This update process will ultimately enable ClockBuilder Pro users to access all
features and register setting values documented in this data sheet and the Si5341/40 Family Reference Manual.
However, if you must enable or access a feature or register setting value so that the device starts up with this
feature or a register setting, but the feature or register setting is NOT yet available in CBPro, you must contact a
Silicon Labs applications engineer for assistance. An example of this type of feature or custom setting is the
customizable amplitudes for the clock outputs. After careful review of your project file and custom requirements, a
Silicon Labs applications engineer will email back your CBPro project file with your specific features and register
settings enabled, using what is referred to as the manual "settings override" feature of CBPro. "Override" settings
to match your request(s) will be listed in your design report file. Examples of setting "overrides" in a CBPro design
report are shown below:
Setting Overrides
Location
Customer Name
Engineering Name
Type
Target
Dec
Value
Hex
Value
0x0435[0]
FORCE_HOLD_PLLA
OLA_HO_FORCE
No NVM
N/A
1
0x1
0x0B48[0:4]
OOF_DIV_CLK_DIS
OOF_DIV_CLK_DIS
User
OPN & EVB
0
0x00
Once you receive the updated design file, simply open it in CBPro. After you create a custom OPN, the device will
begin operation after startup with the values in the NVM file, including the Silicon Labs-supplied override settings.
Place sample order
Start
Do I need a pre‐programmed device with a feature or setting which is unavailable in ClockBuilder Pro?
No
Configure device using CBPro
Generate Custom OPN in CBPro
Yes
Contact Silicon Labs Technical Support
to submit & review your non‐standard configuration request & CBPro project file
Receive updated CBPro project file from
Silicon Labs with “Settings Override”
Yes
Load project file
into CBPro and test
Does the updated CBPro Project file match your
requirements?
Figure 18. Flowchart to Order Custom Parts with Features not Available in CBPro
38
Rev. 1.0
Si5341/40
6. Register Map
The register map is divided into multiple pages where each page has 256 addressable registers. Page 0 contains
frequently accessible registers such as alarm status, resets, device identification, etc. Other pages contain
registers that need less frequent access such as frequency configuration, and general device settings. A high level
map of the registers is shown in section “6.2. High-Level Register Map” . Refer to the Si5341/40 Family Reference
Manual for a complete list of registers descriptions and settings.
6.1. Addressing Scheme
The device registers are accessible using a 16-bit address which consists of an 8-bit page address + 8-bit register
address. By default the page address is set to 0x00. Changing to another page is accomplished by writing to the
‘Set Page Address’ byte located at address 0x01 of each page.
6.2. High-Level Register Map
Table 17. High-Level Register Map
16-Bit Address
Content
8-bit Page
Address
8-bit Register
Address Range
00
00
Revision IDs
01
Set Page Address
02–0A
Device IDs
0B–15
Alarm Status
17–1B
INTR Masks
1C
Reset controls
2C–E1
Alarm Configuration
E2–E4
NVM Controls
FE
Device Ready Status
01
Set Page Address
08–3A
Output Driver Controls
41–42
Output Driver Disable Masks
FE
Device Ready Status
01
Rev. 1.0
39
Si5341/40
Table 17. High-Level Register Map (Continued)
16-Bit Address
8-bit Page
Address
8-bit Register
Address Range
02
01
Set Page Address
02–05
XTAL Frequency Adjust
08–2F
Input Divider (P) Settings
30
Input Divider (P) Update Bits
35–3D
PLL Feedback Divider (M) Settings
3E
PLL Feedback Divider (M) Update Bit
47–6A
Output Divider (R) Settings
6B–72
User Scratch Pad Memory
FE
Device Ready Status
01
Set Page Address
02–37
MultiSynth Divider (N0–N4) Settings
0C
MultiSynth Divider (N0) Update Bit
17
MultiSynth Divider (N1) Update Bit
22
MultiSynth Divider (N2) Update Bit
2D
MultiSynth Divider (N3) Update Bit
38
MultiSynth Divider (N4) Update Bit
39–58
FINC/FDEC Settings N0–N4
59–62
Output Delay (t) Settings
63–94
Frequency Readback N0–N4
FE
Device Ready Status
04–08
00–FF
Reserved
09
01
Set Page Address
49
Input Settings
1C
Zero Delay Mode Settings
00–FF
Reserved
03
A0–FF
40
Content
Rev. 1.0
Si5341/40
7. Pin Descriptions
XA
8
XB
9
X2
10
GND
Pad
41
VDDO3
42
OUT3
7
34
X1
OUT3
OUT6
43
35
44
6
36
5
RST
37
SYNC
VDD
OUT6
I2C_SEL
IN_SEL1
45
38
4
FB_IN
VDD
IN_SEL1
40
VDD
FB_IN
VDDO7
46
41
OUT7
49
3
IN0
OUT7
50
LOL
IN_SEL0
42
VDDO8
51
FINC
47
IN0
OUT8
52
48
2
43
OUT8
53
1
IN1
44
RSVD
OUT9
58
54
OUT9
59
55
VDD
60
VDDO9
FB_IN
61
RSVD
FB_IN
62
56
IN0
63
57
IN0
64
IN1
39
Si5340 44QFN
Top View
Si5341 64QFN
Top View
IN1
1
33
INTR
IN1
2
32
IN_SEL0
3
31
VDD
OUT2
VDDO6
X1
4
30
OUT2
OUT5
XA
5
29
VDDO2
OUT5
XB
6
28
LOS_XAXB
7
27
LOL
8
26
VDDS
25
OUT1
40
VDDO5
39
I2C_SEL
X2
VDDA
GND
Pad
Rev. 1.0
17
18
19
20
21
22
RST
OUT0
OUT0
VDD
NC
16
A0/CS
VDDO0
15
12
A1/SDO
32
VDD
14
31
OUT2
SCLK
30
OUT2
13
29
OE
SDA/SDIO
28
VDDO3
OUT1
VDDO2
OUT3
33
27
34
16
26
15
OUT1
IN2
SCLK
VDDO1
OUT3
25
35
FDEC
14
24
VDDO1
IN2
OUT0
23
23
11
OUT0
IN2
22
VDDO4
VDDO0
36
21
13
RSVD
OUT1
VDDA
20
24
RSVD
10
19
IN2
A0/CS
VDDA
OUT4
18
OUT4
37
17
38
12
A1/SDO
11
INTR
SDA/SDIO
OE
9
41
Si5341/40
Table 18. Pin Descriptions
Pin Number
Pin Type1
Function
5
I
9
6
I
Crystal and External Clock Input
These pins are used to connect an external crystal or an external
clock. See section “5.3.1. XA/XB Clock and Crystal Input” and
“Figure 11. XAXB External Crystal and Clock Connections” for
connection information. If IN_SEL[1:0] = 11b, then the XAXB input
is selected. If the XAXB input is not used and powered down, then
both inputs can be left unconnected. ClockBuilder Pro will power
down an input that is set as "Unused".
X1
7
4
I
X2
10
7
I
IN0
63
43
I
IN0
64
44
I
IN1
1
1
I
IN1
2
2
I
IN2
14
10
I
IN2
15
11
I
FB_IN
61
41
I
FB_IN
62
42
I
Pin Name
Si5341
Si5340
XA
8
XB
Inputs
XTAL Shield
Connect these pins directly to the XTAL ground pins. X1, X2, and
the XTAL ground pins must not be connected to the PCB ground
plane. DO NOT GROUND THE CRYSTAL GROUND PINS. Refer
to the Si5341/40 Family Reference Manual for layout guidelines.
These pins should be left disconnected when connecting XA/XB
pins to an external reference clock.
Clock Inputs
These pins accept both differential and single-ended clock signals. Refer to "5.3.2. Input Clocks (IN0, IN1, IN2)" on page 30 for
input termination options. These pins are high-impedance and
must be terminated externally. If both the INx and INx (with overstrike) inputs are un-used and powered down, then both inputs
can be left floating. ClockBuilder Pro will power down an input that
is set as "Unused".
External Feedback Input
These pins are used as the external feedback input (FB_IN/
FB_IN) for the optional zero delay mode. See "5.5.13. Zero Delay
Mode" on page 36 for details on the optional zero delay mode. If
FB_IN and FB_IN (with overstrike) are un-used and powered
down, then both inputs can be left floating. ClockBuilder Pro will
power down an input that is set as "Unused".
Notes:
1. I = Input, O = Output, P = Power.
2. The IO_VDD_SEL control bit (0x0943 bit 0) selects 3.3 V or 1.8 V operation for the serial interface pins, control input
pins, and status output pins. Refer to the Si5341/40 Family Reference Manual for more information on register settings.
3. If neither serial interface is used, leave pins I2C_SEL, A1/SDO, and A0/CS disconnected and tie SDA/SDIO and SCLK
low.
42
Rev. 1.0
Si5341/40
Table 18. Pin Descriptions (Continued)
Pin Number
Pin Type1
Function
20
O
23
19
O
OUT1
28
25
O
OUT1
27
24
O
OUT2
31
31
O
Output Clocks
These output clocks support a programmable signal amplitude
when configured as a differential output. Desired output signal format is configurable using register control. Termination recommendations are provided in "5.5.2. Differential Output Terminations"
on page 32 and "5.5.5. LVCMOS Output Terminations" on page
33. Unused outputs should be left unconnected.
OUT2
30
30
O
OUT3
35
36
O
OUT3
34
35
O
OUT4
38
—
O
OUT4
37
—
O
OUT5
42
—
O
OUT5
41
—
O
OUT6
45
—
O
OUT6
44
—
O
OUT7
51
—
O
OUT7
50
—
O
OUT8
54
—
O
OUT8
53
—
O
OUT9
59
—
O
OUT9
58
—
O
Pin Name
Si5341
Si5340
OUT0
24
OUT0
Outputs
Notes:
1. I = Input, O = Output, P = Power.
2. The IO_VDD_SEL control bit (0x0943 bit 0) selects 3.3 V or 1.8 V operation for the serial interface pins, control input
pins, and status output pins. Refer to the Si5341/40 Family Reference Manual for more information on register settings.
3. If neither serial interface is used, leave pins I2C_SEL, A1/SDO, and A0/CS disconnected and tie SDA/SDIO and SCLK
low.
Rev. 1.0
43
Si5341/40
Table 18. Pin Descriptions (Continued)
Pin Name
Pin Number
Si5341
Si5340
Pin Type1
Function
Serial Interface
I2C_SEL
39
38
I
I2C Select2
This pin selects the serial interface mode as I2C (I2C_SEL = 1) or
SPI (I2C_SEL = 0). This pin is internally pulled up by a ~ 20 k
resistor to the voltage selected by the IO_VDD_SEL register bit.
SDA/SDIO
18
13
I/O
Serial Data Interface2
This is the bidirectional data pin (SDA) for the I2C mode, or the
bidirectional data pin (SDIO) in the 3-wire SPI mode, or the input
data pin (SDI) in 4-wire SPI mode. When in I2C mode, this pin
must be pulled-up using an external resistor of at least 1 k. No
pull-up resistor is needed when in SPI mode.
A1/SDO
17
15
I/O
Address Select 1/Serial Data Output2
In I2C mode, this pin functions as the A1 address input pin and
does not have an internal pull up or pull down resistor. In 4-wire
SPI mode this is the serial data output (SDO) pin (SDO) pin and
drives high to the voltage selected by the IO_VDD_SEL pin.
SCLK
16
14
I
Serial Clock Input2
This pin functions as the serial clock input for both I2C and SPI
modes.This pin is internally pulled up by a ~20 k resistor to the
voltage selected by the IO_VDD_SEL register bit. In I2C mode
this pin should have an external pull up of at least 1 k. No pull-up
resistor is needed when in SPI mode.
A0/CS
19
16
I
Address Select 0/Chip Select2
This pin functions as the hardware controlled address A0 in I2C
mode. In SPI mode, this pin functions as the chip select input
(active low). This pin is internally pulled up by a ~20 k resistor to
the voltage selected by the IO_VDD_SEL register bit.
Notes:
1. I = Input, O = Output, P = Power.
2. The IO_VDD_SEL control bit (0x0943 bit 0) selects 3.3 V or 1.8 V operation for the serial interface pins, control input
pins, and status output pins. Refer to the Si5341/40 Family Reference Manual for more information on register settings.
3. If neither serial interface is used, leave pins I2C_SEL, A1/SDO, and A0/CS disconnected and tie SDA/SDIO and SCLK
low.
44
Rev. 1.0
Si5341/40
Table 18. Pin Descriptions (Continued)
Pin Number
Pin Type1
Function
33
O
Interrupt2
This pin is asserted low when a change in device status has
occurred. This interrupt has a push pull output and should be left
unconnected when not in use.
6
17
I
Device Reset2
Active low input that performs power-on reset (POR) of the
device. Resets all internal logic to a known state and forces the
device registers to their default values. Clock outputs are disabled
during reset. This pin is internally pulled up with a ~20 k resistor
to the voltage selected by the IO_VDD_SEL bit.
OE
11
12
I
Output Enable2
This pin disables all outputs when held high. This pin is internally
pulled low and can be left unconnected when not in use.
LOL
47
—
O
Loss Of Lock2
This output pin indicates when the DSPLL is locked (high) or outof-lock (low). An external pull up or pull down is not needed.
—
27
O
Loss Of Lock
This output pin indicates when the DSPLL is locked (high) or outof-lock (low). An external pull up or pull down is not needed. The
voltage on the VDDS pin sets the VOH/VOL for this pin. See
Table 6.
LOS_XAXB
—
28
O
Loss Of Signal
This output pin indicates a loss of signal at the XA/XB pins.
SYNC
5
—
I
Output Clock Synchronization2
An active low signal on this pin resets the output dividers for the
purpose of re-aligning the output clocks. For a tighter alignment of
the clocks, a soft reset should be applied. This pin is internally
pulled up with a ~20 k resistor to the voltage selected by the
IO_VDD_SEL bitand can be left unconnected when not in use.
FDEC
25
—
I
Frequency Decrement Pin2
This pin is used to step-down the output frequency of a selected
output. The affected output driver and its frequency change step
size is register configurable. This pin is internally pulled low with a
~20 k resistor and can be left unconnected when not in use.
Pin Name
Si5341
Si5340
INTR
12
RST
Control/Status
Notes:
1. I = Input, O = Output, P = Power.
2. The IO_VDD_SEL control bit (0x0943 bit 0) selects 3.3 V or 1.8 V operation for the serial interface pins, control input
pins, and status output pins. Refer to the Si5341/40 Family Reference Manual for more information on register settings.
3. If neither serial interface is used, leave pins I2C_SEL, A1/SDO, and A0/CS disconnected and tie SDA/SDIO and SCLK
low.
Rev. 1.0
45
Si5341/40
Table 18. Pin Descriptions (Continued)
Pin Number
Pin Type1
Function
—
I
Frequency Increment Pin2
This pin is used to step-up the output frequency of a selected output. The affected output and its frequency change step size is register configurable. This pin is internally pulled low with a ~20 k
resistor and can be left unconnected when not in use.
3
3
I
IN_SEL1
4
37
I
Input Reference Select2
The IN_SEL[1:0] pins are used in the manual pin controlled mode
to select the active clock input as shown in Table 15. These pins
are internally pulled up with a ~20 k resistor to the voltage
selected by the IO_VDD_SEL bit and can be left unconnected
when not in use.
RSVD
20
—
—
21
—
—
55
—
—
56
—
—
—
22
—
No Connect
These pins are not connected to the die. Leave disconnected.
32
21
P
46
32
Core Supply Voltage
The device core operates from a 1.8 V supply. A 1.0 µf bypass
capacitor is recommended
60
39
—
40
13
8
P
—
9
P
Core Supply Voltage 3.3 V
This core supply pin requires a 3.3 V power source.
A 1.0 µf bypass capacitor is recommended.
—
26
P
Pin Name
Si5341
Si5340
FINC
48
IN_SEL0
NC
Reserved
These pins are connected to the die. Leave disconnected.
Power
VDD
VDDA
VDDS
Status Output Voltage
The voltage on this pin determines the VOL/VOH on LOL and
LOS_XAXB status output pins.
A 0.1 µf to 1.0 µf bypass capacitor is recommended.
Notes:
1. I = Input, O = Output, P = Power.
2. The IO_VDD_SEL control bit (0x0943 bit 0) selects 3.3 V or 1.8 V operation for the serial interface pins, control input
pins, and status output pins. Refer to the Si5341/40 Family Reference Manual for more information on register settings.
3. If neither serial interface is used, leave pins I2C_SEL, A1/SDO, and A0/CS disconnected and tie SDA/SDIO and SCLK
low.
46
Rev. 1.0
Si5341/40
Table 18. Pin Descriptions (Continued)
Pin Number
Pin Type1
Function
18
P
26
23
P
VDDO2
29
29
P
VDDO3
33
34
P
VDDO4
36
—
P
Output Clock Supply Voltage 0–9
Supply voltage (3.3 V, 2.5 V, 1.8 V) for OUTx, OUTx outputs.
See the Si5341/40 Family Reference Manual for power supply filtering recommendations.
Leave VDDO pins of unused output drivers unconnected. An
alternate option is to connect the VDDO pin to a power supply and
disable the output driver to minimize current consumption.
VDDO5
40
—
P
VDDO6
43
—
P
VDDO7
49
—
P
VDDO8
52
—
P
VDDO9
57
—
P
Pin Name
Si5341
Si5340
VDDO0
22
VDDO1
GND PAD
P
Ground Pad
This pad provides electrical and thermal connection to ground and
must be connected for proper operation. Use as many vias as
practical and keep the via length to an internal ground plan as
short as possible.
Notes:
1. I = Input, O = Output, P = Power.
2. The IO_VDD_SEL control bit (0x0943 bit 0) selects 3.3 V or 1.8 V operation for the serial interface pins, control input
pins, and status output pins. Refer to the Si5341/40 Family Reference Manual for more information on register settings.
3. If neither serial interface is used, leave pins I2C_SEL, A1/SDO, and A0/CS disconnected and tie SDA/SDIO and SCLK
low.
Rev. 1.0
47
Si5341/40
8. Ordering Guide
Si534fg-Rxxxxx-GM
Timing product family
f = Clock generator family member (1, 0)
g = Device grade (A, B)
Product Revision*
Custom ordering part number (OPN) sequence ID**
Package, ambient temperature range (QFN, -40°C to +85°C)
*See Ordering Guide table for current product revision
** 5 digits; assigned by ClockBuilder Pro
Ordering
Part Number
(OPN)
Number of
Input/Output
Clocks
Output Clock
Frequency Range
(MHz)
Frequency
Synthesis Mode
Package
Temperature
Range
64-Lead
9x9 QFN
–40 to 85 °C
44-Lead
7x7 QFN
–40 to 85 °C
Evaluation
Board
—
Si5341
Si5341A-B-GM1,2
Si5341B-B-GM
0.0001 to 712.5 MHz
1,2
Si5341C-B-GM
1,2
4/10
Si5341D-B-GM1,2
0.0001 to 350 MHz
0.0001 to 712.5 MHz
0.0001 to 350 MHz
Integer and
fractional mode
Integer mode only
Si5340
Si5340A-B-GM1,2
Si5340B-B-GM1,2
Si5340C-B-GM1,2
0.0001 to 712.5 MHz
4/4
Si5340D-B-GM1,2
0.0001 to 350 MHz
0.0001 to 712.5 MHz
0.0001 to 350 MHz
Integer and
fractional mode
Integer Only
Si5341/40-EVB
Si5341-EVB
Si5340-EVB
—
—
—
Notes:
1. Add an R at the end of the OPN to denote tape and reel ordering options.
2. Custom, factory pre-programmed devices are available. Ordering part numbers are assigned by Silicon Labs and the
ClockBuilder Pro software utility.
3. Custom part number format is: e.g., Si5341A-Bxxxxx-GM, where “xxxxx” is a unique numerical sequence representing
the preprogrammed configuration.
4. See Sections 5.9 and 5.10 for important notes about specifying a preprogrammed device to use features or device
register settings not yet available in CBPro.
48
Rev. 1.0
Si5341/40
9. Package Outlines
9.1. Si5341 9x9 mm 64-QFN Package Diagram
Figure 19 illustrates the package details for the Si5341. Table 19 lists the values for the dimensions shown in the
illustration.
Figure 19. 64-Pin 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
9.00 BSC
5.10
5.20
e
0.50 BSC
E
9.00 BSC
5.30
E2
5.10
5.20
5.30
L
0.30
0.40
0.50
aaa
—
—
0.15
bbb
—
—
0.10
ccc
—
—
0.08
ddd
—
—
0.10
eee
—
—
0.05
Notes:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.
3. This drawing conforms to the JEDEC Solid State Outline MO-220.
4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020
specification for Small Body Components.
Rev. 1.0
49
Si5341/40
9.2. Si5340 7x7 mm 44-QFN Package Diagram
Figure 20 illustrates the package details for the Si5340. Table 20 lists the values for the dimensions shown in the
illustration.
Figure 20. 44-Pin Quad Flat No-Lead (QFN)
Table 20. 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
7.00 BSC
5.10
5.20
e
0.50 BSC
E
7.00 BSC
5.30
E2
5.10
5.20
5.30
L
0.30
0.40
0.50
aaa
—
—
0.15
bbb
—
—
0.10
ccc
—
—
0.08
ddd
—
—
0.10
Notes:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.
3. This drawing conforms to the JEDEC Solid State Outline MO-220.
4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020
specification for Small Body Components.
50
Rev. 1.0
Si5341/40
10. PCB Land Pattern
Figure 21 illustrates the PCB land pattern details for the devices. Table 21 lists the values for the dimensions
shown in the illustration.
Si5341
Si5340
Figure 21. PCB Land Pattern
Rev. 1.0
51
Si5341/40
Table 21. PCB Land Pattern Dimensions
Dimension
Si5341 (Max)
Si5340 (Max)
C1
8.90
6.90
C2
8.90
6.90
E
0.50
0.50
X1
0.30
0.30
Y1
0.85
0.85
X2
5.30
5.30
Y2
5.30
5.30
Notes:
General
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. This Land Pattern Design is based on the IPC-7351 guidelines.
3. All dimensions shown are at Maximum Material Condition (MMC). Least
Material Condition is calculated based on a fabrication Allowance of 0.05 mm.
Solder Mask Design
4. 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
5. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls
should be used to assure good solder paste release.
6. The stencil thickness should be 0.125 mm (5 mils).
7. The ratio of stencil aperture to land pad size should be 1:1 for all perimeter
pads.
8. A 3x3 array of 1.25 mm square openings on 1.80 mm pitch should be used for
the center ground pad.
Card Assembly
9. A No-Clean, Type-3 solder paste is recommended.
10. The recommended card reflow profile is per the JEDEC/IPC J-STD-020
specification for Small Body Components.
52
Rev. 1.0
Si5341/40
11. Top Marking
Si5341gRxxxxx-GM
YYWWTTTTTT
e4
TW
Si5340gRxxxxx-GM
YYWWTTTTTT
TW
e4
64-QFN
44-QFN
Figure 22. Si5341-40 Top Markings
Table 22. Si5341-40 Top Marking Explanation
Line
Characters
Description
1
Si5341gSi5340g-
Base part number and Device Grade for Low Jitter, Any-Frequency, 10output Clock Generator.
Si5341: 10-output, 64-QFN
Si5340: 4-output, 44-QFN
g = Device Grade (A, B, C, D). See "8. Ordering Guide" on page 48 for
more information.
– = Dash character.
2
Rxxxxx-GM
R = Product revision. (See ordering guide for current revision).
xxxxx = Customer specific NVM sequence number. Optional NVM code
assigned for custom, factory pre-programmed devices.
Characters are not included for standard, factory default configured
devices. See Ordering Guide for more information.
–GM = Package (QFN) and temperature range (–40 to +85 °C)
3
YYWWTTTTTT
YYWW = Characters correspond to the year (YY) and work week (WW)
of package assembly.
TTTTTT = Manufacturing trace code.
4
Circle w/ 1.6 mm (64-QFN) Pin 1 indicator; left-justified
or 1.4 mm (44-QFN)
diameter
e4
TW
Pb-free symbol; Center-Justified
TW = Taiwan; Country of Origin (ISO Abbreviation)
Rev. 1.0
53
Si5341/40
12. Device Errata
Please log in or register at www.silabs.com to access the device errata document.
54
Rev. 1.0
Si5341/40
DOCUMENT CHANGE LIST
Revision 0.9 to Revision 0.95
Removed
advanced product information
revision history.
Updated Ordering Guide and changed
references to revision B
Updated parametric Tables 2,3,5,6,7,8 to reflect
production characterization
Updated terminology to align with ClockBuilder
Pro software
9: I2C data hold time specification
corrected to 100 ns from 5 µs
Table
Revision 0.95 to Revision 1.0
General
updates to typos in Tables 2,3,4,5,8,11,
and 12.
Changed Vin_diff minimum value in Table 3 to
be the same as Vin_se.
Added crosstalk spec for Si5340 to Table 5.
Changed the schematic for AC Test
Configuration in Table 7.
Changed the PLL lock time in Table 8.
Added a spec to Table 8 for the VCO frequency
range.
Changed the "Delay Time Between Chip
Selects" to be 2.0 clock periods.
Changed Note 2 in Table 12 as only 25 and 48–
54 Mhz crystals are supported.
the timing specs for I2C and SPI.
Added a 1.0 µf bypass capacitor
recommendation to be consistent with the
reference manual.
Updated output-to-output skew spec.
Changed
Rev. 1.0
55
Si5341/40
CONTACT INFORMATION
Silicon Laboratories Inc.
400 West Cesar Chavez
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:
https://www.siliconlabs.com/support/pages/contacttechnicalsupport.aspx
and register to submit a technical support request.
Patent Notice
Silicon Labs invests in research and development to help our customers differentiate in the market with innovative low-power, small size, analogintensive mixed-signal solutions. Silicon Labs' extensive patent portfolio is a testament to our unique approach and world-class engineering team.
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 support or sustain life, or for any other application in which the failure of the Silicon Laboratories product could create a situation where
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56
Rev. 1.0