General Description

The MAX3996 is a high-speed laser driver for small-

form-factor (SFF) fiber optic LAN transmitters. It con-

tains a bias generator, a laser modulator, and

comprehensive safety features. Automatic power con-

trol (APC) adjusts the laser bias current to maintain

average optical power, regardless of changes in tem-

perature or laser properties. The driver accommodates

common anode or differential laser configurations. The

output current range of the MAX3996 is appropriate for

VCSELs and high-efficiency edge-emitting lasers.

The MAX3996 operates up to 3.2Gbps. It can switch up

to 30mA of laser modulation current and sink up to

60mA bias current. Adjustable temperature compensa-

tion is provided to keep the optical extinction ratio with-

in specifications over the operating temperature range.

The MAX3996 accommodates various laser packages,

including low-cost TO-46 headers. Low deterministic jit-

(65ps) provides excellent margins compared to indus-

try-standard transmitter eye masks.

This laser driver provides extensive safety features to

guarantee single-point fault tolerance. Safety features

include a transmit disable, redundant shutdown, and

laser-bias monitoring. The safety circuit detects faults

that could cause hazardous light levels and immediate-

ly disables the laser output. The MAX3996 safety cir-

cuits are compliant with SFF and small-form-factor

pluggable (SFP) multisource agreements (MSA).

20-pin QFN package and a 20-pin thin QFN package. It

operates over a temperature range of 0°C to +70°C.

Applications

Fibre Channel Optical Transmitters

VCSEL Transmitters

Gigabit Ethernet Optical Transmitters

ATM LAN Optical Transmitters

10 Gigabit Ethernet WWDM

Features

o 3.0V to 5.5V Supply Voltage

o Automatic Power Control

o Integrated Safety Circuits

o 30mA Laser Modulation Current

o Temperature Compensation of Modulation

Current

o Compliant with SFF and SFP MSA

3.0V to 5.5V, 2.5Gbps VCSEL

and Laser Driver

________________________________________________________________ Maxim Integrated Products

1

MAX3996

0.01

µF

0.01

µF

N.C.

0.01

µF

0.01

µF

0.01

µF

L1*

25

Ω

OPTIONAL SHUTDOWN

CIRCUITRY

1.8k

Ω

TX_DISABLE

FAULT

IN+

IN-

PORDLY

TC

MODSET

MON1 MON2 COMP

GND

MD

BIAS

OUT+

OUT-

SHDNDRV

*FERRITE BEAD

Typical Application Circuit

Ordering Information

19-2194; Rev 3; 5/04

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

PART

TEMP

RANGE

PIN-

PACKAGE

PACKAGE

CODE

MAX3996CGP

0°C to +70°C

20 QFN

G2044-3

MAX3996CTP+

0°C to +70°C

20 Thin QFN

T2044-3

Pin Configuration appears at end of data sheet.

+Denotes Lead-Free Package