15. Electrical Characteristics > AC Timing Specifications
227
PEB383 User Manual
July 25, 2011
Integrated Device Technology, Inc.
Confidential - NDA Required
15.6.3
PCIe Differential Receiver Input Specifications
The following table lists the specification of parameters for the differential output of the PCIe lanes.
Table 48: PCIe Differential Receiver Input Specifications
Symbol
Parameter
Min.
Nom.
Max.
Units
Comments
UI
Unit Interval
399.88
400
400.12
ps
Each UI is 400ps +/-300ppm. Ui does
not account for SSC dictated
variations.
See Note 7.
V
RX-DIFFp-p
Differential Peak to
Peak Input Voltage
0.175
-
1.200
V
V
RX-DIFFp-p
= 2*|V
RX-D+
- V
RX-D-
|
See Note 8.
T
RX-EYE
Minimum RX Eye
Width
0.4
-
-
UI
The maximum interconnect media and
Transmitter jitter that can be tolerated
by the Receiver can be derived as
T
RX-MAX-JITTER
= 1 - T
RX-EYE
= 0.6 UI.
See Notes 8, 9, and 10.
T
RX-EYE-MEDIAN-
to-MAX-JITTER
Maximum time
between the jitter
median and maximum
deviation from the
median
-
-
0.3
UI
Jitter is defined as the measurement
variation of the crossing points
(V
RX-DIFF
= 0V) in relation to
recovered TX UI.
To be measured after the clock
recovery function in Section 4.3.3.2 of
the
PCI Express Base Specification
(Revision 1.1)
.
See Notes 8and 9.
V
RX-CM-ACp
RMS AC Peak
Common Mode Input
Voltage
-
-
150
mV
V
RX-CM-AC
= |V
RX-D+
+ V
RX-D-
|/2 -
V
RX-CM-DC
V
RX-CM-DC
= DC
(AVG)
of |V
RX-D+
+
V
RX-D-
|/2
See Note 8.
RL
RX-DIFF
Differential Return
Loss
10
-
-
dB
Measured over 50 MHz to 1.25 GHz.
See Note 11.
RL
RX-CM
Common Mode Return
Loss
6
-
-
dB
Measured over 50 MHz to 1.25 GHz.
See Note 11.
Z
RX-DIFF-DC
DC Differential Input
Impedance
80
-
120
Ohms
RX DC Differential Mode impedance.
See Note 12.
Z
RX-DC
DC Input Impedance
40
50
60
Ohms
Required RX D+ as well as D- DC
impedance (50 Ohm +/- 20%
tolerance).
See Notes 8 and 12.
Z
RX-HIGH-IMP-DC
Powered Down DC
Input Impedance
200K
-
-
Ohms
Required RX D+ as well as D- DC
impedance when the Receiver
terminations do not have power.
See Note 13.