MAX3946 Datasheet | Maxim Integrated

19-5182; Rev 0; 3/10 .. TION KIT EVALUA BLE AVAILA 1.0625Gbps to 11.3Gbps, SFP+ Laser Driver with Laser Impedance Mismatch Tolerance General Description The MAX3946 is a +3.3V, multirate, low-power laser diode driver designed for Ethernet and Fibre Channel transmission systems at data rates up to 11.3Gbps. This device is optimized to drive a differential transmitter optical subassembly (TOSA) with a 25I flex circuit. The unique design of the output stage enables use of unmatched TOSAs, greatly reducing headroom limitations and lowering power consumption. The device receives differential CML-patible signals with on-chip line termination. It can deliver laser modulation current of up to 80m A, at an edge speed of 20ps (20% to 80%), into a 5I to 25I external differential load. The device is designed to have a symmetrical output stage with on-chip back 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 pensate for the SFP+ connector. The integrated bias circuit provides programmable laser bias current up to 80m A. 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 ponents. The MAX3946 is available in a 4mm x 4mm, 24-pin TQFN package. Modules S Up to 100m W Power Consumption Reduction by Features S 225m W Power Dissipation Enables < 1W SFP+ Enabling the Use of Unmatched FP/DFB TOSAs S Supports SFF-8431 SFP+ MSA and SFF-8472 Digital Diagnostic S 225m W Power Dissipation at 3.3V (IMOD = 40m A, IBIAS = 60m A Assuming 25I TOSA) S Single +3.3V Power Supply S Up to 11.3Gbps (NRZ) Operation S Programmable Modulation Current from 10m A to 100m A (5I...