MAX3946,pdf,datasheet,low-powe

The MAX3946 is a +3.3V, mul tira te, low-power laser diodedriver designed f or Ethernetand Fibre Channel transmission systems at data rates up to 11.3Gbps. This device is optimized to drive a differential transmiter optical subassembly (TOSA) with a 25Ω flex circuit. The unique design of the output stage enables use of unmatched TO SAs, greatly reducing he adroom limitations and lowering power consumption.

The dev ice receives differential CML-compatible signals with on-chip line termination. It candeliver laser modulation current of up to 80mA, at an edge speed of 20ps (20% to 80%), into a 5Ω to 25Ω external differential load. The device is designed to have a symmetrical output stage with on-chip b ack terminations integrated into its outputs. A high-bandwidth, fully differential signal path is implemented to minimize deterministic jitter. An equalization block can be activated to compensate for the SFP+ connector. The integrated bias circuit provides prog rammable laser bias current up to 80mA. Both the laser bias generator and the laser modulator can be disabled from a single pin, DISABLE.

A 3-wire digital interface reduces the pin count and permits adjustment of input equalization, pulse-width adjustment, Tx polarity, Tx deemphasis, modulation current, and bias current without the need for external components. The MAX3946 is av ailable in a 4mm x 4mm, 24-pin TQFN package.