26 Gbps Multi-Rate Burst Mode Laser Driver with Limiting Amplifier, Dual CDRs, Power Management and Diagnostics

 The MALD-37035B is a transceiver IC with dual CDRs targeted for burst mode direct modulated Laser (DML) applications. The MALD-37035B is intended for 25GS-PON and 25G EPON applications. The CDRs in the TX and RX channels are reference-free and can be programmed to support half rate as well as bypassed to support legacy or non-standard data rates. The TX channel includes a CTLE with adaptive/programmable equalization and a flexible output driver to directly drive DML lasers in TO-Cans or in hybrid packages. A buck-boost converter tracks the laser forward voltage and automatically generates laser anode voltages from 2.5V to 3.6V to optimize power dissipation and maintain eye quality. The RX channel includes a high-sensitivity limiting amplifier with programmable peaking, slice level, LOS circuit with programmable threshold and hysteresis, a high performance CDR with programmable loop bandwidth, and an output driver with programmable output swing and 2-tap de-emphasis. The MALD-37035B is assembled in a 5 mm x 6 mm LGA (Land Grid Array) package and supports on-chip diagnostic features like PRBS (31/9) generation, PRBS31 error detector and bi-directional loop-back. The device is controlled through an I2C interface. The device is powered from a single 3.3V supply but an internal 1.8V buck converter supplies most of the chip current.