VSC7984
Datasheet
AC Characteristics
Specifications are guaranteed over the recommended operating conditions listed in Table 3, page 10. Data input
31
pattern at PRBS 2 –1 and 11.3 Gbps, unless otherwise noted.
Table 2. AC Characteristics
Symbol
fDATA
fCLK
Parameter
Data rate
Clock rate
MinImum
Typical
11.3
Maximum
12.5
Unit
Condition
Gbps NRZ.
GHz
1
11.3
12.5
VIN
Single-ended data input voltage
amplitude
0.3
1.0
V
AC-coupled, measured peak-
to-peak. See Figure 9.
Differential data input voltage
amplitude
0.3
0.4
0.4
1.0
1.0
V
AC-coupled, measured peak-
to-peak (150 mV per side).
See Figure 9.
VCLK
Single-ended clock input voltage
amplitude
V
V
AC-coupled, measured peak-
to-peak.
See Figure 9.
Differential clock input voltage
amplitude
1.0
AC-coupled, measured peak-
to-peak (200 mV per side).
See Figure 9.
VOC
Output compliance voltage
VCC – 3.5
V
V
RL = 50 Ω, VCC – VEE ≥ 4.9 V
VOM ≤ 2.7 V. See Figure 3.
VCC – 3.3
RL = 50 Ω, VCC – VEE ≥ 4.75 V
VOM ≤ 2.7 V. See Figure 3.
VOM
Output modulation voltage
Disabled output current
1.4
2.7
5
V
mA
ps
%
RL = 50 Ω.
IOM_DIS
tR, tF
ENABLE = LOW.
Output rise time and fall time
Data eye crossing point range
25
35
85
7
20% to 80%, RL = 50 Ω.
See Figure 6 and Figure 7.
DCC
25
–7
DCCSTAB Data eye crossing point stability
%
VPW
Pulse width control input(1)
VEE + 0.5
VEE + 2.5
V
For 50% crossing point at
OUT, set VPW = VEE + 1.1 V.
See Figure 6.
–OVS
+OVS
Output undershoot /overshoot
Clock select
–12
10
%
VOM > 1.4 V.
CSEL
Floating
V
Unclocked mode.
Clocked mode.
VEE
0
VEE + 0.3
V
tS
Setup time
Hold time
–11
25
ps
ps
ps
ps
ps
ps
dB
dB
dB
dB
See Figure 8.
tH
30
See Figure 8.
JTOT_rms
Total jitter, rms
2.1
2.2
12
4
6
Clocked mode.
Unclocked mode.
Clocked mode.
JTOT_p-p
Total jitter, peak-to-peak
Clock input return loss
Data input return loss
Data output return loss
16
18
14
Unclocked mode.
1 GHz to 10 GHz.
10 GHz to 15 GHz.
50 MHz to 10 GHz.
10 GHz to 15 GHz.
50 MHz to 7.5 GHz.
7.5 GHz to 10 GHz.
S11
–11
–9
S11
–11
–10
–11
–9
S22
1. The VSC7984 is capable of moving the data eye crossing point to the very top and bottom of the eye diagram.
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VMDS-10029 Revision 4.1
January 19, 2007
VITESSE [ VITESSE SEMICONDUCTOR CORPORATION ]
