9ZX21901C
19-Output Differential Zbuffer for PCIe Gen2/3 and QPI
Pin Description
PIN #
1
2
PIN NAME
VDDA
GNDA
IREF
PIN TYPE
PWR
PWR
DESCRIPTION
3.3V power for the PLL core.
Ground pin for the PLL core.
This pin establishes the reference for the differential current-mode output pairs.
It requires a fixed precision resistor to ground. 475ohm is the standard value
for 100ohm differential impedance. Other impedances require different values.
See data sheet.
3
OUT
Input to select operating frequency
1 = 100MHz, 0 = 133.33MHz
4
5
100M_133M#
IN
IN
Trilevel input to select High BW, Bypass or Low BW mode.
See PLL Operating Mode Table for Details.
Notifies device to sample latched inputs and start up on first high assertion, or
exit Power Down Mode on subsequent assertions. Low enters Power Down
Mode.
HIBW_BYPM_LOBW#
6
CKPWRGD_PD#
IN
7
8
GND
PWR
PWR
Ground pin.
3.3V power for differential input clock (receiver). This VDD should be treated
as an analog power rail and filtered appropriately.
0.7 V Differential TRUE input
VDDR
9
10
DIF_IN
DIF_IN#
IN
IN
0.7 V Differential Complementary Input
SMBus address bit. This is a tri-level input that works in conjunction with the
SMB_A1 to decode 1 of 9 SMBus Addresses.
Data pin of SMBUS circuitry, 5V tolerant
11
SMB_A0_tri
IN
12
13
SMBDAT
SMBCLK
I/O
IN
Clock pin of SMBUS circuitry, 5V tolerant
SMBus address bit. This is a tri-level input that works in conjunction with the
SMB_A0 to decode 1 of 9 SMBus Addresses.
No Connection.
14
SMB_A1_tri
IN
15
16
NC
NC
N/A
N/A
No Connection.
Complementary half of differential feedback output, provides feedback signal
to the PLL for synchronization with input clock to eliminate phase error.
17
DFB_OUT#
OUT
True half of differential feedback output, provides feedback signal to the PLL
for synchronization with the input clock to eliminate phase error.
0.7V differential true clock output
0.7V differential Complementary clock output
Power supply, nominal 3.3V
0.7V differential true clock output
0.7V differential Complementary clock output
0.7V differential true clock output
0.7V differential Complementary clock output
Ground pin.
0.7V differential true clock output
0.7V differential Complementary clock output
0.7V differential true clock output
0.7V differential Complementary clock output
Power supply, nominal 3.3V
18
DFB_OUT
OUT
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
DIF_0
DIF_0#
VDD
DIF_1
DIF_1#
DIF_2
DIF_2#
GND
DIF_3
DIF_3#
DIF_4
DIF_4#
VDD
OUT
OUT
PWR
OUT
OUT
OUT
OUT
PWR
OUT
OUT
OUT
OUT
PWR
OUT
OUT
DIF_5
DIF_5#
0.7V differential true clock output
0.7V differential Complementary clock output
Active low input for enabling DIF pair 5.
1 =disable outputs, 0 = enable outputs
0.7V differential true clock output
34
OE5#
IN
35
36
DIF_6
DIF_6#
OUT
OUT
0.7V differential Complementary clock output
1648H- 12/08/11
IDT® 19-Output Differential Zbuffer for PCIe Gen2/3 and QPI
3