Si52112 A1 A2

S i 5 2 11 2 - A 1 / A 2
PCI-E XPRESS G EN 1 DUAL O UTPUT C LOCK G ENERATOR
Features







PCI-Express Gen 1 compliant

Low power HCSL differential

output buffers
Supports Serial-ATA (SATA) at 
100 MHz
No termination resistors required 
25 MHz Crystal Input or Clock
input

Triangular spread spectrum
profile for maximum EMI

reduction (Si52112-A2)
Extended Temperature:
–40 to 85 °C
3.3 V Power supply
Small package 10-pin TDFN
(3x3 mm)
Si52112-A1 does not support
spread spectrum outputs
Si52112-A2 supports 0.5% down
spread outputs
For PCIe Gen 2 applications, see
Si52112-B3/B4
For PCIe Gen 3 applications, see
Si52112-B5/B6
Ordering Information:
See page 13
Pin Assignments
Applications
Network Attached Storage
 Multi-function Printer
Wireless Access Point
 Routers

VDD
VDD
1
10
XOUT
2
9
DIFF2
XIN/CLKIN
3
8
DIFF2
VSS
4
7
DIFF1
VSS
5
6
DIFF1

Description
Si52112-A1/A2 is a high-performance, PCIe clock generator that can
source two PCIe clocks from a 25 MHz crystal or clock input. The clock
outputs are compliant to PCIe Gen 1 specifications. The ultra-small
footprint (3x3 mm) and industry leading low power consumption make
Si52112-A1/A2 the ideal clock solution for consumer and embedded
applications.
Patents pending
VDD
DIFF1
XIN/CLKIN
PLL
Divider
DIFF2
XOUT
VSS
Rev 1.2 7/14
Copyright © 2014 by Silicon Laboratories
Si52112-A1/A2
Si52112-A1/A2
2
Rev 1.2
Si52112-A1/A2
TABLE O F C ONTENTS
Section
Page
1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2. Crystal Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
2.1. Crystal Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
2.2. Calculating Load Capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
3. Test and Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
4. Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.1. 10-Pin TDFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.2. 8-Pin TSSOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6. Package Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
6.1. TDFN Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.2. TSSOP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7. Recommended Design Guideline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Rev 1.2
3
Si52112-A1/A2
1. Electrical Specifications
Table 1. Recommended Operating Conditions
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
VDD(extended)
3.3 V ± 5%
3.13
3.3
3.46
V
VDD(commercial)
3.3 V ± 10%
2.97
3.3
3.63
V
Symbol
Test Condition
Min
Typ
Max
Unit
Operating Voltage
VDD
3.3 V ± 10%
2.97
3.30
3.63
V
Operating Supply Current
IDD
Full Active
—
—
17
mA
Input Pin Capacitance
CIN
Input Pin Capacitance
—
3
5
pF
COUT
Output Pin Capacitance
—
—
5
pF
Supply Voltage (extended)
Supply Voltage (commercial)
Table 2. DC Electrical Specifications
Parameter
Output Pin Capacitance
4
Rev 1.2
Si52112-A1/A2
Table 3. AC Electrical Specifications
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
LACC
Measured at VDD/2 differential
—
—
250
ppm
TDC
Measured at VDD/2
45
—
55
%
CLKIN Rise and Fall Times
TR/TF
Measured between 0.2 VDD and
0.8 VDD
0.5
—
4.0
V/ns
CLKIN Cycle-to-Cycle Jitter
TCCJ
Measured at VDD/2
—
—
250
ps
CLKIN Long Term Jitter
TLTJ
Measured at VDD/2
—
—
350
ps
Input High Voltage
VIH
XIN/CLKIN pin
2
—
VDD+0.3
V
Input Low Voltage
VIL
XIN/CLKIN pin
—
—
0.8
V
Input High Current
IIH
XIN/CLKIN pin, VIN = VDD
—
—
35
uA
Input Low Current
IIL
XIN/CLKIN pin, 0 < VIN <0.8
–35
—
—
uA
TDC
Measured at 0 V differential
45
—
55
%
TSKEW
Measured at 0 V differential
—
—
60
ps
Output Frequency
FOUT
VDD = 3.3 V
—
100
—
MHz
Frequency Accuracy
FACC
All output clocks
—
—
100
ppm
tr/f2
Measured differentially from
±150 mV
0.6
—
4.0
V/ns
TCCJ
Measured at 0 V differential
—
28
70
ps
Pk-PkGEN1
PCIe Gen 1
—
24
86
ps
VOX
300
—
550
mV
Voltage High
VHIGH
—
—
1.15
V
Voltage Low
VLOW
–0.3
—
—
V
Spread Range
SRNG
Down Spread, -A2 only
—
–0.5
—
%
Modulation Frequency
FMOD
-A2 only
30
31.5
33
kHz
TSTABLE
—
—
3
ms
TSS
10.0
—
—
ns
Crystal
Long-term Accuracy
Clock Input
CLKIN Duty Cycle
DIFF Clocks
Duty Cycle
Skew
Slew Rate
Cycle-to-Cycle Jitter
PCIe Gen 1 Pk-Pk Jitter
Crossing Point Voltage at 0.7 V
Swing
Enable/Disable and Set-up
Clock Stabilization from Powerup
Stopclock Set-up Time
Note: Visit www.pcisig.com for complete PCIe specifications.
Rev 1.2
5
Si52112-A1/A2
Table 4. Thermal Conditions
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
Temperature, Storage
TS
Non-functional
–65
—
150
°C
Temperature, Operating Ambient
TA
Functional
–40
—
85
°C
Temperature, Junction
TJ
Functional
—
—
150
°C
Dissipation, Junction to Case (TDFN)
ØJC
JEDEC (JESD 51)
—
—
38.3
°C/W
Dissipation, Junction to Case (TSSOP)
ØJC
JEDEC (JESD 51)
—
—
37.0
°C/W
Dissipation, Junction to Ambient (TDFN)
ØJA
JEDEC (JESD 51)
—
—
90.4
°C/W
Dissipation, Junction to Ambient (TSSOP)
ØJA
JEDEC (JESD 51)
—
—
124.0 °C/W
Min
Typ
Max
Unit
—
—
4.6
V
Table 5. Absolute Maximum Conditions
Parameter
Main Supply Voltage
Input Voltage
ESD Protection (Human Body Model)
Flammability Rating
Symbol
Test Condition
VDD_3.3V
VIN
Relative to VSS
–0.5
—
4.6
VDC
ESDHBM
JEDEC (JESD 22 - A114)
2000
—
—
V
UL-94
UL (Class)
V–0
Note: While using multiple power supplies, the voltage on any input or I/O pin cannot exceed the power pin during power-up.
Power supply sequencing is not required.
6
Rev 1.2
Si52112-A1/A2
2. Crystal Recommendations
If using a crystal input, the device requires a parallel resonance crystal.
Table 6. Crystal Recommendations
Frequency Cut Loading Load Cap
(Fund)
25 MHz
AT
Parallel
ESR
Drive
Shunt
Motional Tolerance Stability
Cap (max)
(max)
(max)
(max)
12–15 pF <50  >150 µW
5 pF
0.016 pF
35 ppm
30 ppm
Aging
(max)
5 ppm
2.1. Crystal Loading
Crystal loading is critical in achieving low ppm performance. To realize low ppm performance, use the total
capacitance the crystal sees to calculate the appropriate capacitive loading (CL).
Figure 1 shows a typical crystal configuration using two trim capacitors. It is important that the trim capacitors are in
series with the crystal.
Figure 1. Crystal Capacitive Clarification
Rev 1.2
7
Si52112-A1/A2
2.2. Calculating Load Capacitors
In addition to the standard external trim capacitors, consider the trace capacitance and pin capacitance to calculate
the crystal loading correctly. Again, the capacitance on each side is in series with the crystal. The total capacitance
on both sides is twice the specified crystal load capacitance (CL). Trim capacitors are calculated to provide equal
capacitive loading on both sides.
Figure 2. Crystal Loading Example
Use the following formulas to calculate the trim capacitor values for Ce1 and Ce2.
Load Capacitance (each side)
Ce = 2  CL –  Cs + Ci 
Total Capacitance (as seen by the crystal)
1
CLe = ------------------------------------------------------------------------------------------------------1
1
 --------------------------------------------- + --------------------------------------------
 Ce1 + Cs1 + Ci1 Ce2 + Cs2 + Ci2
CL:
Crystal load capacitance
Actual loading seen by crystal using standard value trim capacitors
Ce: External trim capacitors
Cs: Stray capacitance (terraced)
Ci: Internal capacitance (lead frame, bond wires, etc.)
CLe:
8
Rev 1.2
Si52112-A1/A2
3. Test and Measurement Setup
Figures 3 through 5 show the test load configuration for the differential clock signals.
M e a s u re m e n t
P o in t
L1
O U T+
5 0
2 pF
L1 = 5"
O U T-
M e a s u re m e n t
P o in t
L1
5 0
2 pF
Figure 3. 0.7 V Differential Load Configuration
Figure 4. Differential Measurement for Differential Output Signals
(for AC Parameters Measurement)
Rev 1.2
9
Si52112-A1/A2
Figure 5. Single-ended Measurement for Differential Output Signals
(for AC Parameters Measurement)
10
Rev 1.2
Si52112-A1/A2
4. Pin Descriptions
4.1. 10-Pin TDFN
VDD
VDD
1
10
XOUT
2
9
DIFF2
XIN/CLKIN
3
8
DIFF2
VSS
4
7
DIFF1
VSS
5
6
DIFF1
Figure 6. 10-Pin TDFN
Table 7. 10-Pin TDFN Descriptions
Pin #
Name
Type
Description
1
VDD
2
XOUT
O
25.00 MHz crystal output, Float XOUT if using only CLKIN (clock input).
3
XIN/CLKIN
I
25.00 MHz crystal input or 3.3 V, 25 MHz clock Input.
4
VSS
GND
Ground.
5
VSS
GND
Ground.
6
DIFF1
O, DIF 0.7 V, 100 MHz differential clock output.
7
DIFF1
O, DIF 0.7 V, 100 MHz differential clock output.
8
DIFF2
O, DIF 0.7 V, 100 MHz differential clock output.
9
DIFF2
O, DIF 0.7 V, 100 MHz differential clock output.
10
VDD
PWR 3.3 V power supply.
PWR 3.3 V power supply.
Rev 1.2
11
Si52112-A1/A2
4.2. 8-Pin TSSOP
VDD 1
8 DIFF2
XOUT 2
7 DIFF2
XIN/CLKIN 3
Si52112
VSS 4
6 DIFF1
5 DIFF1
Figure 7. 8-Pin TSSOP
Table 8. 8-Pin TSSOP Descriptions
Pin #
Name
1
VDD
2
XOUT
O
25.00 MHz crystal output, Float XOUT if using only CLKIN (clock input).
3
XIN/CLKIN
I
25.00 MHz crystal input or 3.3 V, 25 MHz clock Input.
4
VSS
GND
5
DIFF1
O, DIF 0.7 V, 100 MHz differentials clock.
6
DIFF1
O, DIF 0.7 V, 100 MHz differentials clock.
7
DIFF2
O, DIF 0.7 V, 100 MHz differentials clock.
8
DIFF2
O, DIF 0.7 V, 100 MHz differentials clock.
12
Type
Description
PWR 3.3 V Power supply.
Ground.
Rev 1.2
Si52112-A1/A2
5. Ordering Guide
Part Number
Spread Option
Package Type
Temperature
Si52112-A1-GM2
No Spread
10-pin TDFN
Extended, –40 to 85 °C
Si52112-A1-GM2R
No Spread
10-pin TDFN—Tape and Reel
Extended, –40 to 85 °C
Si52112-A1-GT
No Spread
8-pin TSSOP
Extended, –40 to 85 °C
Si52112-A1-GTR
No Spread
8-pin TSSOP - Tape and Reel
Extended, –40 to 85 °C
Si52112-A2-GM2
–0.5% Spread
10-pin TDFN
Extended, –40 to 85 °C
Si52112-A2-GM2R
–0.5% Spread
10-pin TDFN—Tape and Reel
Extended, –40 to 85 °C
Si52112-A2-GT
–0.5% Spread
8-pin TSSOP
Extended, –40 to 85 °C
Si52112-A2-GTR
–0.5% Spread
8-pin TSSOP - Tape and Reel
Extended, –40 to 85 °C
Si52112
Ax
Base part number
A: Product Revision A
x=1: non spread outputs
x=2: -0.5% spread outputs
GM2R/GTR
Operating Temp Range:
G: -40 to +85 °C
M2 :10-TDFN Package, ROHS6, Pb-free
T: 8-TSSOP Package, ROHS6, Pb-free
R: Tape & Reel
(blank) = Tubes
Figure 8. Ordering Information
Rev 1.2
13
Si52112-A1/A2
6. Package Outlines
6.1. TDFN Package
Figure 9 illustrates the package details for the 10-pin TDFN. Table 9 lists the values for the dimensions shown in
the illustration.
Figure 9. 10-Pin TDFN Package Drawing
14
Rev 1.2
Si52112-A1/A2
Table 9. TDFN Package Diagram Dimensions
Symbol
Min
Nom
Max
A
0.70
0.75
0.80
A1
0.00
0.02
0.05
A3
b
0.20 REF.
0.18
D
D2
0.25
0.30
3.00 BSC.
1.90
2.00
e
0.50 BSC
E
3.00 BSC
2.10
E2
1.40
1.50
1.60
L
0.25
0.30
0.35
aaa
0.10
bbb
0.10
ccc
0.10
ddd
0.10
eee
0.08
Notes:
1. All dimensions shown are in millimeters (mm) unless otherwise
noted.
2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.
3. Recommended card reflow profile is per the JEDEC/IPC J-STD-020
specification for Small Body Components.
4. This drawing conforms to the JEDEC Solid State Outline MO-229.
Rev 1.2
15
Si52112-A1/A2
6.2. TSSOP Package
Figure 10 illustrates the package details for the 8-pin TSSOP. Table 10 lists the values for the dimensions shown in
the illustration.
Figure 10. 8-Pin TSSOP Package Drawing
16
Rev 1.2
Si52112-A1/A2
Table 10. TSSOP Package Diagram Dimensions
Symbol
Min
Nom
Max
A
—
—
1.20
A1
0.05
—
0.15
A2
0.80
0.90
1.05
b
0.19
—
0.30
c
0.09
—
0.20
D
2.90
3.00
3.10
E
E1
6.40 BSC
4.30
e
L
4.50
0.65 BSC
0.45
L2
θ
4.40
0.60
0.75
0.25 BSC
0°
—
aaa
0.10
bbb
0.10
ccc
0.05
ddd
0.20
8°
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-153,
Variation AA.
4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020C
specification for Small Body Components.
Rev 1.2
17
Si52112-A1/A2
7. Recommended Design Guideline
3.3 V
VDD
4.7 µF
0.1 µF
Si5211x
Note: FB Specifications:
DC resistance 0.1–0.3 
Impedance at 100 MHz > 1000 
Figure 11. Recommended Application Schematic
18
Rev 1.2
Si52112-A1/A2
DOCUMENT CHANGE LIST
Revision 1.0 to Revision 1.1


Removed references to Gen 2.
Updated package outlines.
Revision 1.1 to Revision 1.2

Added “4.2. 8-Pin TSSOP” pin description on
page 12.
Rev 1.2
19
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