ADS7843

FEATURES

q 4-WIRE TOUCH SCREEN INTERFACE

q RATIOMETRIC CONVERSION

q SINGLE SUPPLY: 2.7V to 5V

q UP TO 125kHz CONVERSION RATE

q SERIAL INTERFACE

q PROGRAMMABLE 8- OR 12-BIT RESOLUTION

q 2 AUXILIARY ANALOG INPUTS

q FULL POWER-DOWN CONTROL

®

International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111

Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132

DESCRIPTION

The ADS7843 is a 12-bit sampling analog-to-digital

converter (ADC) with a synchronous serial interface

and low on-resistance switches for driving touch

screens. Typical power dissipation is 750

µW at a

125kHz throughput rate and a +2.7V supply. The

reference voltage (V

+V

of 0V to V

which reduces typical power dissipation to under

0.5

µW. The ADS7843 is guaranteed down to 2.7V

operation.

Low power, high speed, and on-board switches make

the ADS7843 ideal for battery operated systems such

as personal digital assistants with resistive touch screens

and other portable equipment. The ADS7843 is avail-

able in a 16-lead SSOP package and is guaranteed

over the –40

°C to +85°C temperature range.

APPLICATIONS

q PERSONAL DIGITAL ASSISTANTS

q PORTABLE INSTRUMENTS

q POINT-OF-SALES TERMINALS

q PAGERS

q TOUCH-SCREEN MONITORS

PDS-1441C

Printed in U.S.A. June, 1998

TOUCH SCREEN CONTROLLER

CDAC

SAR

Comparator

Four

Channel

Multiplexer

Serial

Interface

and

Control

CS

DIN

DOUT

BUSY

DCLK

X+

PENIRQ

X–

Y+

Y–

IN3

IN4

V

REF

+V

CC