DS25BR400_08 Datasheet, PDF (9/14 Pages) National Semiconductor (TI) – Quad 2.5 Gbps CML Transceiver with Transmit De-Emphasis and Receive Equalization

Symbol
Parameter
Conditions
Min
DRIVER SPECIFICATIONS
VODB
Output Differential
Voltage Swing without
De-Emphasis
R_L = 100Ω ±1%
PreA_1 = 0; PreA_0 = 0
PreB_1 = 0; PreB_0 = 0
Driver de-emphasis disabled.
Running K28.7 pattern at 2.5 Gbps.
(Figure 6)
V_PE
Output De-Emphasis R_L = 100Ω ±1%
Voltage Ratio
Running K28.7 pattern at 2.5 Gbps
20*log(VODPE/VODB) _{PreX_[1:0] = 00}
PreX_[1:0] = 01
PreX_[1:0] = 10
PreX_[1:0] = 11
X = A/B channel de-emphasis drivers
(Figure 1 / Figure 6)
t_PE
De-Emphasis Width Tested at −9 dB de-emphasis level, PreX[1:0] = 11
X = A/B channel de-emphasis drivers
See Figure 5 on measurement condition.
R_OTSE
R_OTD
Output Termination
Output Differential
Termination
On-chip termination from OUT+ or OUT− to V_CC
On-chip differential termination between OUT+ and
OUT−
ΔR_OTSE
Mis-Match in Output Mis-match in output termination resistors
Termination Resistors
V_OCM
Output Common Mode
Voltage
POWER DISSIPATION
P_D
Power Dissipation
V_DD = 3.465V
All outputs terminated by 100Ω ±1%.
PreB_[1:0] = 0, PreA_[1:0] = 0
Running PRBS 2⁷-1 pattern at 2.5 Gbps
AC CHARACTERISTICS
t_R
Differential Low to High Measured with a clock-like pattern at 2.5 Gbps,
Transition Time
between 20% and 80% of the differential output
t_F
Differential High to Low ^voltage.
Transition Time
De-emphasis disabled.
Transition time is measured with the fixture shown
in Figure 6 adjusted to reflect the transition time at
the output pins.
t_PLH
Differential Low to High Measured at 50% differential voltage from input to
Propagation Delay
output.
t_PHL
Differential High to Low
Propagation Delay
t_SKP
Pulse Skew
t_SKO
Output Skew
(Note 7)
|t_PHL–t_PLH|
Difference in propagation delay between channels
on the same part
(Channel-to-Channel Skew)
t_SKPP
Part-to-Part Skew
(Note 7)
Difference in propagation delay between devices
across all channels operating under identical
conditions
t_LB
Loopback Delay Time Delay from enabling loopback mode to signals
appearing at the differential outputs
Figure 4
1000
 
 
 
125
42
Typ
(Note 2)
1200
 
 
0
−3
−6
−9
200
50
100
2.7
80
80
Max
1400
 
 
 
250
58
5
1.3
1
1
20
100
165
4
Units
mV_P-P
 
 
dB
dB
dB
dB
ps
Ω
Ω
%
V
W
ps
ps
ns
ns
ps
ps
ps
ns
9
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