LXT6155LE popular Programmable IC Chips 155 Mbps SDH / SONET / ATM Transceiver

The LXT6155 is a high speed fully integrated transceiver designed for 155 Mbps SDH/SONET/ ATM transmission system applications. The LXT6155 provides a LVPECL interface for fiber optics modules, and a CMI interface for coax cable drive. These circuits are implemented using Level One’s proven low power 3.3V CMOS analog and digital circuits.

The transmitter incorporates a parallel-to-serial converter, a frequency multiplier PLL, CMI line encoders, and line interfaces for both coax cable and optical fiber. The receiver incorporates an adaptive equalizer, a clock recovery PLL, Loss of Signal (LOS) detector, CMI and NRZ decoders, a serial-to-parallel converter, and an SDH/SONET frame byte detector/aligner. At the system interface, the LXT6155 offers both parallel 8-bit and serial differential interfaces. The LXT6155 also operates in either Hardware stand-alone mode or Software mode. Software mode is controlled by a serial microprocessor (µP) to program formats and operating/test modes.

Applications

• OC3/STM1 SDH/SONET Cross Connects
  
• OC3/STM1 SDH/SONET Add/Drop Mux
  
• OC3/STM1 Transmission Systems
  
• OC3/STM1 Short Haul Serial Links
  
• OC3/STM1 ATM/WAN Transmission Systems
  
• OC3/STM1 ATM/WAN Access Systems

Features

* Complies with:

—Bellcore SONET GR-253

—ITU-T G.703/813/958 STM1

* Two line interface formats:

—Fiber LVPECL NRZ

—Coax CMI

* Transmit synthesizer PLL

* Receive clock recovery PLL

* Adaptive CMI equalizer

* Analog circuitry for transformer drive

* Programmable LOS function

* CMI encoder and decoder

* Serial/Parallel and Parallel/Serial conversion

* Byte alignment for SDH/SONET frames

* Two modes of operation:

—Microprocessor controlled; software mode

—Stand-alone; hardware mode

* No external crystal required. A 19.44 MHz crystal is optional

* Low power consumption (less than 760 mW typical)

* Operates from a single 3.3 V supply

* 64 pin LQFP package

Absolute Maximum Ratings

CAUTION:

Operating at or beyond these limits may result in damage to the device. Normal operation not guaranteed at these extremes.

Figure 1. LXT6155 Block Diagram

LXT6155 Pin Assignments

LXT6155LE Package Specification