General Description

The MAX3735/MAX3735A are +3.3V laser drivers for

SFP/SFF applications from 155Mbps up to 2.7Gbps.

The devices accept differential input data and provide

bias and modulation currents for driving a laser. DC-

coupling to the laser allows for multirate applications

and reduces the number of external components. The

MAX3735/MAX3735A are fully compliant with the SFP

MSA timing and the SFF-8472 transmit diagnostic

requirements.

An automatic power-control (APC) feedback loop is incor-

porated to maintain a constant average optical power

over temperature and lifetime. The wide modulation cur-

rent range of 10mA to 60mA (up to 85mA AC-coupled)

and bias current of 1mA to 100mA make this product

ideal for driving FP/DFB laser diodes in fiber-optic mod-

ules. The resistor range for the laser current settings is

optimized to interface with the DS1858 SFP controller IC.

The MAX3735/MAX3735A provide transmit-disable con-

trol, a single-point latched transmit-failure monitor out-

put, photocurrent monitoring, and bias-current

monitoring to indicate when the APC loop is unable to

maintain the average optical power. The MAX3735A

also features improved multirate operation.

The MAX3735/MAX3735A come in package and die

form, and operate over the extended temperature

range of -40°C to +85°C.

Applications

Gigabit Ethernet SFP/SFF Transceiver Modules

1G/2G Fibre Channel SFP/SFF Transceiver

Modules

Multirate OC3 to OC48-FEC SFP/SFF Transceiver

Modules

Features

o SFP Reference Design Available

o Fully Compliant with SFP and SFF-8472 MSAs

o Programmable Modulation Current from 10mA to

60mA (DC-Coupled)

o Programmable Modulation Current from 10mA to

85mA (AC-Coupled)

o Programmable Bias Current from 1mA to 100mA

o Edge Transition Times <51ps

o 27mA (typ) Power-Supply Current

o Multirate 155Mbps to 2.7Gbps Operation

o Automatic Average Power Control

o On-Chip Pullup Resistor for TX_DISABLE

o 24-Pin 4mm × 4mm QFN package

2.7Gbps, Low-Power SFP Laser Drivers

________________________________________________________________ Maxim Integrated Products

1

Ordering Information

IN+

0.1

µF

MD

BIAS

OUT+

OUT+

OUT-

OPTIONAL SHUTDOWN

CIRCUITRY

IN-

REPRESENTS A CONTROLLED-IMPEDANCE TRANSMISSION LINE

SERDES

MAX3735

MAX3735A

0.1

µF

+3.3V

+3.3V

FERRITE BEAD

+3.3V

10

Ω

15

Ω

0.01

µF

DS1858/DS1859

CONTROLLER

IC

M0N2

M0N3

MON1

H1

H0

+3.3V

Typical Application Circuit

19-2529; Rev 1; 4/03

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.

*Dice are designed to operate from -40°C to +85°C, but are

**EP = Exposed pad.

PART

TEMP RANGE

PIN-PACKAGE

MAX3735E/D

-40°C to +85°C

Dice*

MAX3735ETG

-40°C to +85°C

24 Thin QFN-EP**

MAX3735EGG

-40°C to +85°C

24 QFN-EP**

MAX3735AETG

-40°C to +85°C

24 Thin QFN-EP**

Pin Configuration appears at end of data sheet.

EVALUATION

KIT

AVAILABLE