Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsData collecting ICsData acquisition IC - Digital potentiometer linear Permanent TSSOP 20

General Description

The DS3903 contains three nonvolatile (NV) low tem-

perature coefficient digital potentiometers, which can

be accessed through a 2-wire bus. It operates in both

3V and 5V systems, and it features a write-protect pin

that can lock the positions of the potentiometers. An

address pin allows two DS3903s to be placed on the

same 2-wire bus.

Applications

Power-Supply Calibration

Mobile Phones and PDAs

Fiber Optics Transceiver Modules

Portable Electronics

A Small, Low-Cost Replacement for Mechanical

Potentiometers

Features

♦ Three 128-Position Linear Potentiometers

(Two 10kΩ, One 90kΩ)

♦ NV Wiper Storage

♦ 0 to 5.5V on Any Potentiometer Terminal

Independent of V

♦ Low End-to-End Temperature Coefficient

♦ Operates on an Industry-Standard 2-Wire Bus

♦ Write-Protect Pin

♦ Supply Voltage: 3V or 5V

♦ Operating Temperature Range: -40°C to +85°C

♦ Packaging: 20-Pin TSSOP

DS3903

Triple 128-Position Nonvolatile

Digital Potentiometer

_____________________________________________ Maxim Integrated Products 1

SDA

192

SCL

N.C.

TSSOP

N.C.

GND

DS3903

Pin Configuration

0.1µF

4.7kΩ

2-WIRE

MASTER

VREF1

VREF2

5.1kΩ

Iref

SCL

SDA

POTENTIOMETER 2

10kΩ

ADDDR FAh

POTENTIOMETER 0

10kΩ

ADDDR F9h

POTENTIOMETER 1

90kΩ

ADDDR F8h

GND

4.7kΩ

VARIABLE RESISTANCE

FOR ADJUSTABLE

CURRENT SOURCE

HIGH-OUTPUT-IMPEDANCE

VOLTAGE REFERENCE

BUFFERED

VOLTAGE

REFERENCE

MAX427

DS3903

Typical Operating Circuit

Ordering Information

Rev 0; 6/02

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

DS3903E-020

-40°C to +85°C

20 TSSOP

DS3903E-020/T&R

-40°C to +85°C

20 TSSOP

(Tape-and-Reel)

Summary of content (11 pages)

PAGE 1
Rev 0; 6/02 Triple 128-Position Nonvolatile Digital Potentiometer The DS3903 contains three nonvolatile (NV) low temperature coefficient digital potentiometers, which can be accessed through a 2-wire bus. It operates in both 3V and 5V systems, and it features a write-protect pin that can lock the positions of the potentiometers. An address pin allows two DS3903s to be placed on the same 2-wire bus.
PAGE 2
DS3903 Triple 128-Position Nonvolatile Digital Potentiometer ABSOLUTE MAXIMUM RATINGS Voltage on VCC Pin Relative to Ground.................-0.5V to +6.0V Voltage on SDA, SCL, A0, and WP Relative to Ground ...........................................................-0.5V to VCC + 0.5V Voltage on L0, L1, L2, W0, W1, W2, H0, H1, and H2 Relative to Ground ...........................................-0.5V to +6.0V Current Through W0, W1, and W2......................................
PAGE 3
Triple 128-Position Nonvolatile Digital Potentiometer DS3903 AC ELECTRICAL CHARACTERISTICS (VCC = 2.7V to 5.5V, TA = -40°C to +85°C.
PAGE 4
Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: Note 7: Note 8: Note 9: Note 10: Note 11: All voltages are referenced to ground. ISTBY specified for VCC equal to 3.0V and 5.0V while control port logic pins are driven to the appropriate logic levels. Appropriate logic levels specify that logic inputs are within a 0.5V of ground or VCC for the corresponding inactive state. WP must be disconnected or connected high.
PAGE 5
Triple 128-Position Nonvolatile Digital Potentiometer (VCC = 5.0V, 10kΩ plots apply to both pot0 and pot2, TA = +25°C unless otherwise noted.) WIPER RESISTANCE vs. WIPER VOLTAGE (90kΩ) 200 150 VCC = 3V POS 7Fh 50 1 2 3 4 Tc = 18.0ppm/°C 0.06 WIPER = 60h 0.04 Tc = 3.7ppm/°C 0.02 WIPER = 40h 0 DS3903 toc05 -0.02 Tc = 1.5ppm/°C -0.04 -0.06 1 2 3 4 5 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 WIPER VOLTAGE (V) TEMPERATURE (°C) VOLTAGE-DIVIDER PERCENT CHANGE FROM 25°C vs.
PAGE 6
Typical Operating Characteristics (continued) (VCC = 5.0V, 10kΩ plots apply to both pot0 and pot2, TA = +25°C unless otherwise noted.) VOLTAGE-DIVIDER ABSOLUTE LINEARITY vs. WIPER SETTING (90kΩ) VOLTAGE-DIVIDER RELATIVE LINEARITY vs. WIPER SETTING (90kΩ) ABSOLUTE LINEARTIY (LSB) 0.04 0.03 0.02 DS3903 toc13 0.20 DS3903 toc12 0.05 RELATIVE LINEARTIY (LSB) DS3903 Triple 128-Position Nonvolatile Digital Potentiometer 0.16 0.12 0.08 0.04 0.
PAGE 7
Triple 128-Position Nonvolatile Digital Potentiometer DS3903 VCC RWP EEPROM POTENTIOMETER 2 10kΩ ADDDR FAh POTENTIOMETER 2 ADDDR FAh GND POTENTIOMETER 0 ADDDR F9h SCL SDA 2-WIRE INTERFACE W2 L2 WP POTENTIOMETER 0 10kΩ ADDDR F9h Clock and Data Transitions H2 H0 W0 The SDA pin is normally pulled high with an external resistor or device. Data on the SDA pin can only change during SCL low time periods.
PAGE 8
DS3903 Triple 128-Position Nonvolatile Digital Potentiometer SDA MSB SLAVE ADDRESS R/W DIRECTION BIT ACKNOWLEDGEMENT SIGNAL FROM RECEIVER ACKNOWLEDGEMENT SIGNAL FROM RECEIVER SCL 1 2 6 7 8 9 1 2 3–7 8 ACK START CONDITION 9 ACK REPEATED IF MORE BYTES ARE TRANSFERRED STOP CONDITION OR REPEATED START CONDITION Figure 2. 2-Wire Data Transfer Protocol SDA tBUF tHD:STA tLOW tR tSP tF SCL tHD:STA STOP tSU:STA tHIGH tSU:DAT START REPEATED START tSU:STO tHD:DAT Figure 3.
PAGE 9
Triple 128-Position Nonvolatile Digital Potentiometer The DS3903 is capable of an 8-byte page write. A page write is initiated the same way as a byte write, but the master does not send a stop condition after the first data byte. Instead, after the slave acknowledges the data byte has been received, the master can send up to seven more data bytes using the same nine-clock sequence. After a write to the last byte in the page, the address returns to the beginning of the same page.
PAGE 10
DS3903 Triple 128-Position Nonvolatile Digital Potentiometer The following bus protocol has been defined: Data transfer can be initiated only when the bus is not busy. During data transfer, the data line must remain stable whenever the clock line is high. Changes in the data line while the clock line is high are interpreted as control signals. Accordingly, the following bus conditions have been defined: Bus Not Busy: Both data and clock lines remain high.
PAGE 11
Triple 128-Position Nonvolatile Digital Potentiometer Applications Information Power-Supply Decoupling To achieve the best results when using the DS3903, decouple the power supply with a 0.01µF or 0.1µF capacitor. Use a high-quality ceramic surface-mount capacitor if possible. Surface-mount components minimize lead inductance, which improves performance, and ceramic capacitors tend to have adequate highfrequency response for decoupling applications.