Achronix Speedster22i SerDes - Manual (Page 105)

Transmitter
Table 23: DC and AC Switching Characteristics
Parameter Description Min Typical Max Unit
Output Eye Specification
V
TX-DIFF-PKPK
Backporch Transmit Amplitude 400 1500
mV
diff-
pkpk
V
TX-EYE-PKPK
Transmit Eye Voltage Opening 400 1200
mV
diff-
pkpk
D
TX-N+1-DEEMP
N+1 precursor Tap De-Emphasis 0 2.5 dB
D
TX-N-1-DEEMP
N-1 postcursor Tap De-Emphasis 0 8.5 dB
D
TX-N-2-DEEMP
N-2 postcursor Tap De-Emphasis 0 2.5 dB
T
TX-SLEW
Rise/Fall Time 30 120 ps
T
TX-DDJ
Transmit Dependant Jitter (Inter-
Symbol Interference) at 8Gbps.
Includes package model
0.05 UI
pkpk
T
TX-PJ
Transmit Periodic Jitter. Assumes a
1st order high pass jitter
measurement filter with a cutoff of
F
BAUD
/ F
GPLL =
N
GPLL
0.05 UI
pkpk
T
TX-RJ
Transmit Total Peak-Peak Random
Jitter (assumes 14σ
TXRJ-RMS
). Assumes
a 1st order high pass jitter
measurement filter with a cutoff of
F
BAUD
/ F
GPLL =
N
GPLL
0.15 UI
pkpk
T
TX-TJ
Transmit Total Peak-Peak Jitter
(Assumes T
TX-TJ
= T
TX-DDJ
+ T
TX-PJ
+ T
TX-
RJ
). Assumes a 1st order high pass
jitter measurement filter with a cutoff
of F
BAUD
/ F
GPLL =
N
GPLL
0.25 UI
pkpk
N
GPLL
F3dB cutoff frequency for the 1 st
Order High-Pass Jitter Measurement
Filter.
Defined as the ratio of the F
3DB
cutoff
frequency, to the data rate
1667
F
BAUD
/
F
GPLL
V
TX-CM-PKPK-AC
Pk-PK AC Common Mode Voltage
Variation
100 mV
V
TX-CM-RMS-AC
RMS AC Common Mode Voltage
Variation
20 mV
Transmitter DC Impedance
Z
TX-DIFF-DC
Transmitter Output Differential DC
Impedance
80 100 120 Ω
Z
TX-CM-DC
Transmitter Output Common-Mode
DC Impedance
20 25 30 Ω
UG028, July 1, 2014 105