78P2351R 155Mbps NRZ to CMI Converter
ELECTRICAL SPECIFICATIONS (continued)
DIGITAL I/O CHARACTERISTICS: (continued)
Pins of type PO:
PARAMETER
Signal Swing
SYMBOL
Vpk
CONDITIONS
MIN
0.5
NOM
0.8
MAX
1.1
UNIT
V
Common Mode Level
Effective Source Impedance
Rise Time
Vcm
Reff
Tr
Vdd referenced
-1.4
-1.2
20
-1.1
V
Ω
10-90%
10-90%
0.8
0.8
1.2
1.2
ns
ns
Fall Time
Tf
Pins of type PI:
PARAMETER
SYMBOL
CONDITIONS
MIN
NOM
NOM
MAX
UNIT
Signal Swing
Vpki
0.3
V
Common Mode Level
Vcm
Vdd referenced
-1.6
-0.8
V
Pins of type OD
PARAMETER
SYMBOL
CONDITIONS
MIN
MAX
UNIT
Output Voltage Low
Vol
Iol = 8mA
0.4
V
Pull-down Leakage Current
Pull-up Resistor
Ipd
Rpu
Logic high output
1
10
nA
kΩ
4.7
REFERENCE CLOCK CHARACTERISTICS:
PARAMETER
SYMBOL CONDITIONS
MIN
NOM
MAX
UNIT
CKREF Duty Cycle
--
40
60
%
Synchronous mode
--
-20
+20
CKREF Frequency Stability
ppm
Plesiochronous or Loop-timing
-75
+75
mode. (see Note 1)
Note 1: In Plesiochronous mode, the transmit data source (i.e. framer) must still be of +/-20ppm quality in
order to meet SONET/SDH bit rate requirements.
17