PI6C557-03AQ
PCIe 2.0 Clock Generator with 2 HCSL Outputs
for Automotive Applications
Features Description
PCIe 2.0 compliant e PTh I6C557-03AQ is a spread spectrum clock generator compli -
ant to PCI Express 2.0 and Ethernet requirements. The device is
Phase jitter - 2.1ps RMS (typ)
used for PC or embedded systems to substantially reduce Electro-
LVDS compatible outputs
magnetic Interference (EMI).
Supply voltage of 3.3V 10%
25MHz crystal or clock input frequency
e PTh I6C557-03AQ provides two differential (HCSL) or LVDS
HCSL outputs, 0.8V Current mode differential pair
spread spectrum outputs. The PI6C557-03AQ is configured to se -
Jitter 35ps cycle-to-cycle (typ)
lect spread and clock selection. Using Pericom's patented Phase-
Locked Loop (PLL) techniques, the device takes a 25MHz crystal
Spread of -0.5%, -0.75%, and no spread
input and produces two pairs of differential outputs (HCSL) at
AEC-Q100 qualified
25MHz, 100MHz, 125MHz and 200MHz clock frequencies. It
Spread Bypass option available
also provides spread selection of -0.5%, -0.75%, and no spread.
Spread and frequency selection via external pins
Packaging: (Pb-free and Green)
16-pin TSSOP (L16)
Block Diagram Pin Configuration (16-Pin TSSOP)
VDD
2
SS1:SS0 1
S0
CLK0 16 VDDX
2
Control
CLK0
2
S1 15 CLK0
Logic
S1:S0
Phase
2
3
SS0
Lock 14 CLK0
Loop
4
X1/CLK
13 GNDA
CLK1
X1/CLK
5
X2 12 VDDA
CLK1
Crystal
25 MHz
Driver
6
crystal or clock OE
11 CLK1
X2
7
GNDX
10 CLK1
2
Pulling R
R
8
Capacitors SS1 9 IREF
GND OE
All trademarks are property of their respective owners. www.pericom.com PI6C557-03AQ Rev A 05/22/14
14-0076 1PI6C557-03AQ
PCIe 2.0 Clock Generator with 2 HCSL Outputs for Automotive Applications
Pin Description
Pin # Pin Name I/O Type Description
1 S0 Input Select pin 0 (Internal pull-up resistor). See Table 1.
2 S1 Input Select pin 1 (Internal pull-up resistor). See Table 1.
3 SS0 Input Spread Select pin 0 (Internal pull-up resistor). See Table 2.
4 X1/CLK Input Crystal or clock input. Connect to a 25MHz crystal or single ended clock.
5 X2 Output Crystal connection. Leave unconnected for clock input.
6 OE Input Output enable. Internal pull-up resistor.
7 GNDX Power Crystal ground pin.
8 SS1 Input Spread Select pin 1 (Internal pull-up resistor). See Table 2.
9 IREF Output Precision resistor attached to this pin is connected to the internal current reference.
10 CLK1 Output HCSL compliment clock output
11 CLK1 Output HCSL clock output
12 VDDA Power Connect to a +3.3V source.
13 GNDA Power Output and analog circuit ground.
14 CLK0 Output HCSL compliment clock output
15 CLK0 Output HCSL clock output
16 VDDX Power Connect to a +3.3V source.
Table 1: Output Select Table Table 2: Spread Selection Table
S1 S0 CLK(MHz) SS1 SS0 Spread
0 0 25 0 0 No Spread
0 1 100 0 1 Down -0.5
1 0 125 1 0 Down -0.75
1 1 200 1 1 No Spread
All trademarks are property of their respective owners. www.pericom.com PI6C557-03AQ Rev A 05/22/14
14-0076 2