Advanced Information
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
November 2000
DESCRIPTION
The 78P2253 is a transceiver IC designed for
139.264Mbit/s (E4) or 155.52Mbit/s (OC-3, STS-3 or
STM-1) transmission. It is used at the interface to a
75Ω coaxial cable using CMI coding or a fiber optic
module. Interface to digital framer circuits is
accomplished via a serial PECL or parallel CMOS
interface.
The transmitter includes a PLL to multiply the
reference clock to the transmission frequency. The
receiver provides adaptive equalization for accurate
clock and data recovery. The 78P2253 is built in a
BiCMOS technology for high performance and low
power operation. It operates with a 3.3V or 5V power
supply and is packaged in a 64-pin TQFP.
FEATURES
• 139.264Mbit/s or 155.52Mbit/s interface for
CMI coded transmission using 75W coaxial
cable
• Compliant with ITU-T G.703, G.823 jitter
tolerance, Telcordia TR-NWT-00253
• Integrated Clock Recovery Unit (CRU)
• Serial PECL Interface
• Four and Eight bit Parallel CMOS Interfaces
• PECL Interfaces for connection to Fiber
Optic Modules for SONET OC3 applications
• Adaptive Equalization
• Integrated Clock Multiplier PLL
• Advanced BiCMOS Process
BLOCK DIAGRAM
Crystal
Oscillator
Clock
Generator
Binary
to CMI
Clock
Recovery AdaptiveEqualizer
CMI to
Binary
Bias
XT
AL
2
XT
AL
1
CM
I/ECL
RF
O
LOS
ECLINN
ECLINP
CMIINN
CMIINP
ECLOUTN
ECLOUTP
CMIOUTN
CMIOUTPCKIN
TXCK
TXCKP,N
TXDTP,N
RXDTP,N
RXCKP,N
LL
BACK
RLBACK
LF
Signal
Detector
TXDT[7:0]
RXDT[7:0]
RXCK
8B
IT/
$BIT
E4
/SONET
PAR/
SER
HUB/
HOST