General Description

The DS3902 features a dual, nonvolatile (NV), low tem-

perature-coefficient, variable digital resistor with 256

user-selectable positions. The DS3902 can operate

over a wide supply range of 2.4V to 5.5V, and commu-

compatible serial interface. Internal address settings

allow the DS3902 slave address to be programmed to

one of 128 possible addresses. The low cost and the

small size of the DS3902 make it an ideal replacement

for conventional mechanical-trimming resistors.

Applications

Optical Transceivers

Optical Transponders

Instrumentation and Industrial Controls

RF Power Amps

Audio Power-Amp Biasing

Replacement for Mechanical Variable Resistors

and DIP Switches

Features

♦ Dual 256-Position Linear Digital Resistors

♦ Available as 50kΩ/30kΩ or 50kΩ/15kΩ

♦ Resistor Settings Stored in NV Memory

♦ Low Temperature Coefficient

♦ Wide Operating Voltage (2.4V to 5.5V)

♦ Software Write Protection

♦ User-EEPROM Memory

♦ Programmable Slave Address

♦ Operating Temperature Range: -40°C to +95°C

♦ Small 8-Pin µSOP Package

Dual, NV, Variable Resistors

with User EEPROM

______________________________________________ Maxim Integrated Products

1

SCL

SDA

GND

2-WIRE

MASTER

4.7k

Ω

4.7k

Ω

0.1

µF

H1

H0

OUT-

OUT+

BIAS+

BIAS-

MD

IN+

IN-

TX_FAULT

TX_DISABLE

PC_MON

BS_MON

BIAS SET

MOD SET

NOTES:

1. WITH ADD_SEL TIED TO GND, THE SLAVE ADDRESS WILL BE A2H.

2. FOR A DETAILED APPLICATION DIAGRAM OF A SPECIFIC LD,

CONSULT THE LASER DRIVER DATA SHEET.

LASER

DRIVER IC

DS3902

Typical Operating Circuit

Rev 0; 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.

*Add /T&R for Tape & Reel orders.

Ordering Information

Pin Configuration appears at end of data sheet.

PART

RESISTOR

VALUES

(R0, R1)

TOP

BRAND

PIN-

PACKAGE

DS3902U-530

30k

Ω, 50kΩ

3902A

8 µSOP

DS3902U-515

15k

Ω, 50kΩ

3902B

8 µSOP