Analog Devices Inc./Maxim Integrated MAX3996CGP

Overview

The MAX3996CGP from Maxim Integrated is a high-speed laser driver IC for SFF fiber optic LAN transmitters, integrating bias generation, laser modulation, and safety-critical fault detection. It delivers up to 30mA modulation current and 60mA bias current, supports 2.5Gbps to 3.2Gbps data rates, maintains optical extinction ratio via adjustable temperature compensation, and operates from 3.0V to 5.5V supply across 0°C to +70°C - deployed in VCSEL-based Gigabit Ethernet and Fibre Channel optical modules.

For engineers reviewing the MAX3996CGP datasheet, MAX3996CGP pinout, MAX3996CGP application, or MAX3996CGP equivalent, key selection considerations include deterministic jitter (9ps_P-P), SFF/SFP MSA compliance, APC loop stability with C_COMP, dual-fault monitoring at BIAS/MON2 pins, and compatibility with common-anode or differential laser configurations.

Technical Context

The MAX3996CGP implements an integrated APC loop using MD and COMP pins to regulate average optical power by dynamically adjusting bias current based on monitor diode feedback. Its modulation path uses a high-speed current switch with differential input buffer and matched output drivers (OUT+/OUT−) capable of 65ps edge transitions into 25Ω loads.

Safety architecture includes redundant shutdown via SHDNDRV, latched FAULT output, and independent voltage-threshold fault detection at TC, MODSET, BIAS, MON2, and MD pins - all compliant with SFF-8472 and SFP MSA requirements for single-point fault tolerance in Class 1 laser systems.

Key Specifications

Pinout & Package

MAX3996CGP is housed in a compact 4mm × 4mm, 20-pin QFN package with exposed thermal pad (EP), optimized for high-frequency optical module layouts and requiring soldered ground connection for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX3995C/D and LMH6525, the MAX3996CGP uniquely combines SFP MSA compliance, programmable temperature compensation, integrated APC, and latched safety monitoring - making it the only option qualified for production 2.5Gbps+ optical transceivers requiring Class 1 laser safety certification.

Availability

MAX3996CGP is available at Aetrix Electronics and suitable for Fibre Channel optical transmitters, VCSEL-based SFP modules, and Gigabit Ethernet optical interfaces requiring stable component supply, long-term lifecycle support, and traceable sourcing for industrial and telecom OEMs.

Supply support for MAX3996CGP 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 high-performance analog, mixed-signal, and power management ICs for communications, computing, and industrial applications.

The MAX3996CGP belongs to Maxim's optical communications product line, designed specifically for MSA-compliant, safety-certified laser drivers in pluggable fiber optic transceivers targeting 1G–3.2Gbps data rates.

FAQ

What is the maximum data rate supported by the MAX3996CGP?

The MAX3996CGP supports data rates up to 3.2Gbps, with guaranteed AC performance including 65ps edge transitions and 9ps_P-P deterministic jitter at that rate. It is commonly used in 2.5Gbps Fibre Channel and Gigabit Ethernet applications, where it provides margin against eye mask violations. The MAX3996CGP datasheet specifies full functionality across its entire 0–3.2Gbps range under recommended operating conditions.

How does the MAX3996CGP implement automatic power control (APC)?

The MAX3996CGP implements APC using a closed-loop feedback system: the MD pin connects to the monitor photodiode anode, the BIAS pin drives the laser cathode, and the COMP pin sets the dominant pole via an external capacitor (typically 0.1µF). The internal power-control amplifier adjusts bias current to maintain 1.1V at MD, ensuring stable average optical power across temperature and laser aging. This loop is active only when TX_DISABLE is low and POR delay has expired.

Which safety standards does the MAX3996CGP comply with?

The MAX3996CGP safety circuits comply with SFF-8472 and SFP multisource agreements (MSA), and its fault detection architecture supports compliance with IEC 60825-1 for Class 1 laser products. It monitors critical nodes (BIAS, MON2, TC, MODSET, MD) for single-point faults and responds within 14µs by asserting FAULT and SHDNDRV. However, full system-level IEC 60825 compliance requires proper implementation of external components and layout per Maxim's application notes.

Can the MAX3996CGP drive both VCSELs and edge-emitting lasers?

Yes, the MAX3996CGP is explicitly designed to drive both VCSELs and high-efficiency edge-emitting lasers. Its 30mA modulation current range and 60mA bias current capability accommodate typical VCSEL requirements, while its differential output architecture (OUT+/OUT−), adjustable tempco (via TC and MODSET pins), and support for common-anode configurations make it suitable for 1310nm/1550nm edge-emitters. Layout recommendations include ferrite beads and compensation networks to manage package inductance in either case.

What is the function of the SHDNDRV pin on the MAX3996CGP?

The SHDNDRV pin on the MAX3996CGP provides a redundant, actively driven shutdown signal that goes high during any detected fault condition (e.g., excessive bias current or low BIAS voltage). It is intended to drive an external NPN/PNP transistor in series with the laser bias path, ensuring physical interruption of bias current even if the internal bias driver fails. This dual-shutdown mechanism - internal disable plus SHDNDRV-controlled external cutoff - fulfills SFP MSA and IEC 60825 single-point fault tolerance requirements.