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 25Ω 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-compatible signals with on-chip line termination. It can deliver laser modulation current of up to 80mA, at an edge speed of 22ps (20% to 80%), into a 5Ω to 25Ω 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 compensate for the SFP+ connector. The integrated bias circuit provides programmable laser bias current up to 80mA. Both the laser bias generator and the laser modulator can be disabled from a single pin. 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 available in a 4mm x 4mm, 24-pin TQFN package. Applications * 10GBASE-LR SFP+ Optical Transceivers * 10GBASE-LRM SFP+ Optical Transceivers * 10GFC SFP+ Optical Transceivers * 4x/8x FC SFP+ Optical Transceivers * OC192-SR XFP/SFP+ SDH/SONET Transceivers * 225mW Power Dissipation Enables < 1W SFP+ Modules * Up to 100mW Power Consumption Reduction by Enabling the Use of Unmatched FP/DFB TOSAs * Supports SFF-8431 SFP+ MSA and SFF-8472 Digital Diagnostic * 225mW Power Dissipation at 3.3V (IMOD = 40mA, IBIAS = 60mA Assuming 25Ω TOSA) * Single +3.3V Power Supply * Up to 11.3Gbps (NRZ) Operation * Programmable Modulation Current from 10mA to 100mA (5Ω Load) * Programmable Bias Current from 5mA to 80mA * Programmable Input Equalization * Programmable Output Deemphasis * 25Ω Output Back Termination at TOUT+ and TOUT- * DJ Performance 7psP-P with Mismatched Differential Load (5Ω) * DJ Performance 5psP-P with Mismatched Differential Load (25Ω) * DJ Performance 5psP-P with 50Ω Differential Load * Programmable Pulse Width * Edge Transition Times of 22ps * Bias Current Monitor * Integrated Eye Safety Features * 3-Wire Digital Interface * -40°C to +95°C Operation https://elecena.pl/product/22324469/1gbps-to-11-3gbps-sfp-laser-driver-with-laser-impedance-mismatch-tolerance 2022-12-27 https://elecena.pl/product/22324469/1gbps-to-11-3gbps-sfp-laser-driver-with-laser-impedance-mismatch-tolerance 2025-01-17