MAX3946
NOT RECOMMENDED FOR NEW DESIGNS1Gbps to 11.3Gbps, SFP+ Laser Driver with Laser Impedance Mismatch Tolerance
11.3Gbps Laser Driver Consumes Only 225mW, Ideal for Building < 1W SFP+ Optical Modules
- Part Models
- 2
- 1ku List Price
- Starting From $4.76
Part Details
- 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
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
Documentation
Data Sheet 1
Reliability Data 1
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.
| Part Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| MAX3946ETG+ | 24-LFCSP-4X4X0.75 | ||
| MAX3946ETG+T | 24-LFCSP-4X4X0.75 |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Aug 14, 2023 - 2275A WAFER FAB |
||
| MAX3946ETG+ | PRODUCTION | |
| MAX3946ETG+T | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
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Request a Driver/SoftwareTools & Simulations
Software Development 1
Evaluation Kits
Evaluation Kit for the MAX3946
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