MAX3946

NOT RECOMMENDED FOR NEW DESIGNS

1Gbps 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

Data Sheet (Rev. 1) Product Selection Table

Part Models: 2
1ku List Price: Starting From $4.76

Viewing:

Overview

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 (I_MOD = 40mA, I_BIAS = 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 7ps_P-P with Mismatched Differential Load (5Ω)
DJ Performance 5ps_P-P with Mismatched Differential Load (25Ω)
DJ Performance 5ps_P-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

Part Models: 2
1ku List Price: Starting From $4.76

Documentation

Data Sheet 1

MAX3946: 1Gbps to 11.3Gbps, SFP+ Laser Driver with Laser Impedance Mismatch Tolerance Data Sheet (Rev.1) 05/31/2011

Reliability Data 1

MAX3946 Reliability Data 01/12/2023

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	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
MAX3946ETG+T	24-LFCSP-4X4X0.75	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys

Part Models	Product Lifecycle	PCN

Aug 14, 2023 - 2275A WAFER FAB
		pcn_2275a
MAX3946ETG+	PRODUCTION
MAX3946ETG+T	PRODUCTION

This is the most up-to-date revision of the Data Sheet.

Tools & Simulations

Software Development 1

MAX3946EVKIT Software, 1.0.0

Evaluation Kits

Evaluation Kit for the MAX3946

Buy Now View Details

Features and Benefits

Drives Differential-Connected Lasers
Software Control of the MAX3946
Power Supplied Through USB or External Connection

Product Details

The MAX3946 evaluation kit (EV kit) is an assembled demonstration board that provides optical evaluation of the MAX3946 1.0625Gbps to 11.3Gbps laser driver. The controlling software communicates with the EV kit through the USB port and provides simplified control of all the device functions. The EV kit can be fully powered by the USB port, or the user can choose to power the device by a single external 3.3V supply while the USB port supplies the on-board microcontroller. The flex-cable connection on the EV board allows attachment of lasers incorporating flex cables.