Analog Devices Inc./Maxim Integrated MAX3286CGI

Overview

MAX3286CGI from Maxim Integrated is a 1.25Gbps high-speed laser driver IC optimized for Gigabit Ethernet optical transmitters, integrating bias generator with automatic power control (APC), laser modulator, dual enable/shutdown safety circuitry, and programmable power-on reset. It delivers 30mA modulation current into 25Ω load, achieves 22ps deterministic jitter, and supports common-cathode or common-anode laser configurations with temperature-compensated modulation current.

For engineers reviewing the MAX3286CGI datasheet, MAX3286CGI pinout, MAX3286CGI application, or MAX3286CGI equivalent, this device is selected for fiber-optic LAN transmitter designs requiring single-point fault tolerance, stable optical extinction ratio over 0°C to +70°C, and compatibility with TO-46-packaged shortwave (780–850nm) or longwave (1300nm) laser diodes and VCSELs.

Technical Context

The MAX3286CGI implements a closed-loop APC architecture using MD input feedback to maintain constant average optical power across temperature and laser aging, with REF voltage dynamically derived from MON pin (VREF = 2.65 − 2.25(VCC − VMON)). Its modulation path uses dual-resistor programming (MODSET + TC pins) to set both temperature-stable and temperature-increasing components of laser modulation current, enabling precise extinction ratio control.

Safety logic includes dual latched FAULT/FAULT outputs, FLTDLY-programmable fault delay, and independent shutdown paths via SHDNDRV and internal BIASDRV disable - all compliant with open-fiber control (OFC) requirements. The POR circuit features adjustable delay (via PORDLY capacitor) and hysteresis (3.9V threshold, 2.65V hysteresis) to reject supply noise during hot-plug events.

Key Specifications

Pinout & Package

MAX3286CGI is housed in a 28-pin QFN package (5mm × 5mm, exposed pad grounded), optimized for thermal dissipation and high-frequency signal integrity in optical transmitter modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar laser driver applications.

Compared with MAX3287CTE+, the MAX3286CGI offers full safety configurability (FLTDLY, LV, dual POL) in a larger package; versus MAX3296CTI+, it trades 2.5Gbps capability for lower power and cost in established Gigabit Ethernet deployments.

Availability

MAX3286CGI is available at Aetrix Electronics and suitable for Gigabit Ethernet optical transceivers, Fibre Channel 1GFC modules, and ATM OC-3 interfaces requiring stable component supply, long-term lifecycle support, and traceable sourcing for industrial and telecom OEMs.

Supply support for MAX3286CGI includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in precision analog, mixed-signal, and high-speed interface solutions for communications, computing, and industrial markets.

The MAX3286CGI belongs to Maxim's LAN laser driver product line, designed specifically for fiber-optic transmitter modules needing integrated APC, low-jitter modulation, and comprehensive laser safety compliance in compact QFN packages.

FAQ

What is the maximum laser modulation current supported by the MAX3286CGI?

The MAX3286CGI supports up to 30mA of laser modulation current into a 25Ω load, as specified in the Electrical Characteristics table under "Maximum Laser Modulation Current." This value is achievable with proper resistor selection at MODSET and TC pins and requires that the instantaneous output voltage at OUT+ and OUT− remains above VCC − 1V to maintain linear operation. The MAX3286CGI maintains this current level across its full 0°C to +70°C operating range when configured with appropriate temperature compensation.

How does the MAX3286CGI implement automatic power control (APC)?

The MAX3286CGI implements APC by closing a feedback loop through the MD (monitor diode) pin, which connects to the anode or cathode of the laser's integrated photodiode. The internal power-control amplifier adjusts the BIASDRV output to maintain a stable 1.7V at MD, thereby regulating average optical power. The REF pin voltage (VREF = 2.65 − 2.25(VCC − VMON)) sets the target photocurrent via external RSET, enabling precise APC calibration. This loop operates independently of temperature and laser aging, ensuring consistent output over the lifetime of the MAX3286CGI-based module.

Can the MAX3286CGI drive both VCSELs and edge-emitting laser diodes?

Yes, the MAX3286CGI is explicitly designed to drive vertical-cavity surface-emitting lasers (VCSELs), shortwave (780–850nm) edge-emitting lasers, and longwave (1300nm) lasers. Its MON pin supports VCSEL bias current monitoring, while the configurable POL/POL inputs and common-cathode/common-anode modes accommodate diverse laser pinouts. The datasheet confirms compatibility with TO-46-packaged lasers and specifies performance with 1310nm DFB lasers in eye diagram testing - confirming broad laser diode interoperability within the MAX3286CGI's 1.25Gbps operational envelope.

What safety certifications or compliance does the MAX3286CGI support?

The MAX3286CGI supports IEC 60825-1 Class 1 laser safety compliance through integrated hardware-level safety features: dual latched FAULT/FAULT outputs, redundant EN/EN enable logic, programmable FLTDLY fault delay, and SHDNDRV-driven external MOSFET shutdown. These features enable single-point fault tolerance - meaning any single internal failure (e.g., short to VCC/GND or inter-pin short) triggers immediate laser shutdown. The MAX3286CGI also meets open-fiber control (OFC) requirements via its dual-enable architecture, making it suitable for certified optical transceiver modules without additional safety ASICs.

What is the purpose of the FLTDLY pin on the MAX3286CGI?

The FLTDLY pin on the MAX3286CGI programs the duration of the internal fault-delay pulse that disables safety monitoring during power-up, allowing time for the APC loop to stabilize before fault detection activates. A capacitor connected to FLTDLY (e.g., 0.01µF) sets this delay - typically 5–10× the APC time constant - preventing spurious FAULT assertions at startup. Grounding FLTDLY disables the safety circuit entirely (with EN high and EN low), while leaving it open defaults to minimum delay. This pin is essential for reliable initialization in systems where APC settling time exceeds standard POR timing.