Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsData collecting ICsData acquisition IC - Digital potentiometer linear Non-permanent TSSOP 14

General Description

The DS1805 addressable digital potentiometer contains

a single 256-position digitally controlled potentiometer.

Device control is achieved through a 2-wire serial inter-

face. Device addressing is provided through three

address inputs that allow up to eight devices on a sin-

gle 2-wire bus. The exact wiper position of the poten-

tiometer can be written or read. The DS1805 is

available in 16-pin SO and 14-pin TSSOP packages.

The device is available in three standard resistance val-

ues: 10kΩ, 50kΩ, and 100kΩ. The DS1805 is specified

over the industrial temperature range. The DS1805

provides a low-cost alternative for designs based on

the DS1803, but require only a single potentiometer.

Applications

CCFL Inverters

PDAs and Cell Phones

Portable Electronics

Multimedia Products

Instrumentation and Industrial Controls

Features

♦ 3V or 5V Operation

♦ Low Power Consumption

♦ One Digitally Controlled, 256-Position

Potentiometer

♦ Compatible with DS1803-Based Designs

♦ 14-Pin TSSOP (173mil) and 16-Pin SO (150mil)

Available for Surface-Mount Applications

♦ Three Address Inputs

♦ Serial 2-Wire Bus

♦ Operating Temperature Range

Industrial: -40°C to +85°C

♦ Standard Resistance Values

DS1805-010: 10kΩ

DS1805-050*: 50kΩ

DS1805-100*: 100kΩ

DS1805

Addressable Digital Potentiometer

______________________________________________ Maxim Integrated Products 1

N.C.

N.C.A2

TOP VIEW

N.C.

SDA

SCLGND

14 TSSOP (173mil)

DS1805E

N.C.

SDA

SCL

16 SO (150mil)

N.C.

GND

DS1805Z

Pin Configurations

Ordering Information

PART

TEM P RANGE

PIN- PACKAGE

RESISTANCE

( KΩ)

DS1805E-010

-40°C to +85°C 14 TSSOP (173mil)

DS1805E-050*

-40°C to +85°C 14 TSSOP (173mil)

DS1805E-100*

-40°C to +85°C 14 TSSOP (173mil)

100

DS1805Z-010

-40°C to +85°C

16 SO (150mil) 10

DS1805Z-050*

-40°C to +85°C

16 SO (150mil) 50

DS1805Z-100*

-40°C to +85°C

16 SO (150mil) 100

Rev 1; 9/06

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-and-reel orders.

*Future product.

Summary of content (10 pages)

PAGE 1
Rev 1; 9/06 Addressable Digital Potentiometer The DS1805 addressable digital potentiometer contains a single 256-position digitally controlled potentiometer. Device control is achieved through a 2-wire serial interface. Device addressing is provided through three address inputs that allow up to eight devices on a single 2-wire bus. The exact wiper position of the potentiometer can be written or read. The DS1805 is available in 16-pin SO and 14-pin TSSOP packages.
PAGE 2
DS1805 Addressable Digital Potentiometer ABSOLUTE MAXIMUM RATINGS Voltage on Any Pin Relative to Ground .................-0.5V to +6.0V Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range .............................-55°C to +125°C Soldering Temperature............................................See IPC/JEDEC J-STD-020A Specification Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
PAGE 3
Addressable Digital Potentiometer (VCC = 2.7V to 5.5V, TA = -40°C to +85°C) SYMBOL MAX UNITS End-to-End Resistor Tolerance PARAMETER (Note 6) -20 +20 % Absolute Linearity (Note 7) -0.75 +0.75 LSB Relative Linearity (Note 8) -0.3 +0.3 LSB fCUTOFF -3dB Cutoff Frequency CONDITIONS MIN TYP (Note 9) Hz Ratiometric Temperature Coefficient End-to-End Temperature Coefficient 8 ppm/°C 550 ppm/°C CI Capacitance 5 pF MAX 400 UNITS AC ELECTRICAL CHARACTERISTICS (VCC = 2.7V to 5.
PAGE 4
DS1805 Addressable Digital Potentiometer AC ELECTRICAL CHARACTERISTICS (VCC = 2.7V to 5.5V, TA = -40°C to +85°C) Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: Note 7: Note 8: Note 9: Note 10: Note 11: Note 12: Note 13: Note 14: 4 All voltages are referenced to ground. ICC specified with SDA pin open. SCL = 400kHz clock rate. Address inputs A0, A1, and A2 should be connected to either VCC or GND, depending on the desired address selections.
PAGE 5
Addressable Digital Potentiometer W-L RESISTANCE vs. WIPER SETTING VCC = 3V 15 10 8 6 10kΩ POTENTIOMETER 4 2 5 0 40 60 80 0 WIPER = BFh 0 WIPER = BFh TC = 8.1ppm/°C TC = 1.3ppm/°C 0 DS1805 toc05 45 10kΩ, WORST CASE 0 -1 -2 TC = 530ppm/°C 20 40 60 5 35 30 25 20 15 SDA = VCC A0, A1, A2, L1 = GND W1, H1 = NO CONNECT 10 0 -40 80 40 5 -5 -20 0 20 40 0 80 60 100 TEMPERATURE (°C) TEMPERATURE (°C) VOLTAGE-DIVIDER ABSOLUTE LINEARITY vs. WIPER SETTING (10kΩ) 0.18 0.16 0.14 0.12 0.
PAGE 6
DS1805 Addressable Digital Potentiometer L1 POTENTIOMETER-1 H1 256-TO-1 MULTIPLEXER SRAM REG-0 (8-BIT REGISTER) WIPER-1 (8-BIT REGISTER) W1 SCL COMMAND/ CONTROL UNIT SDA 2-WIRE SERIAL INTERFACE A0 DEVICE ADDRESS SELECTION A1 A2 Figure 1. Functional Diagram Detailed Description Pin Description PIN 6 NAME TSSOP SO 1 1 H1 2 3 L1 3 4 W1 6, 5, 4 7 8 9 10–13 7, 6, 5 8 9 10 2, 11–15 A0, A1, A2 GND SCL SDA N.C.
PAGE 7
Addressable Digital Potentiometer DS1805 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 TRANSFERED STOP CONDITION OR REPEATED START CONDITION Figure 2. 2-Wire Data Transfer Overview The potentiometer is composed of a 256-position resistor array. Two 8-bit registers are provided to ensure compatibility with DS1803-based designs.
PAGE 8
Within the bus specifications a regular mode (100kHz clock rate) and a fast mode (400kHz clock rate) are defined. The DS1805 works in both modes. Acknowledge: Each receiving device, when addressed, is obliged to generate an acknowledge after the reception of each byte. The master device must generate an extra clock pulse that is associated with this acknowledge bit.
PAGE 9
Addressable Digital Potentiometer Command and Protocol The DS1805’s command and protocol structure of the DS1805 allows the user to read or write to both the scratchpad and potentiometer registers. Figures 4 and 5 show the command structures for the part. Potentiometer data values and control and command values are always transmitted most significant bit (MSB) first. During communications, the receiving unit always generates the acknowledge.
PAGE 10
OPTIONAL REGISTER-0 0 1 A2 A1 A0 0 1 LSB 0 1 0 1 DATA BYTE 0 0 1 MSB MSB LSB REG-0 LSB POT-1 STOP 1 MSB ACK 0 LSB ACK START MSB DATA BYTE ACK COMMAND BYTE ACK CONTROL BYTE R/W = 0 WRITE POT-1 A2 A1 A0 0 1 0 1 0 1 0 1 0 LSB POT-1 STOP 1 MSB STOP 0 LSB ACK 1 ACK START 0 DATA BYTE MSB ACK COMMAND BYTE LSB ACK CONTROL BYTE MSB R/W = 0 WRITE REGISTER-0 AND POT-1 (SAME VALUE) CONTROL BYTE COMMAND BYTE 1 0 1 A2 A1 A0 0 1 LSB 0 1 0