FEATURES

4-WIRE TOUCH SCREEN INTERFACE

RATIOMETRIC CONVERSION

SINGLE SUPPLY: 2.7V to 5V

UP TO 125kHz CONVERSION RATE

SERIAL INTERFACE

PROGRAMMABLE 8- OR 12-BIT RESOLUTION

2 AUXILIARY ANALOG INPUTS

FULL POWER-DOWN CONTROL

APPLICATIONS

PERSONAL DIGITAL ASSISTANTS

PORTABLE INSTRUMENTS

POINT-OF-SALES TERMINALS

PAGERS

TOUCH SCREEN MONITORS

DESCRIPTION

The ADS7843 is a 12-bit sampling Analog-to-Digital Converter

(ADC) with a synchronous serial interface and low onresistance

switches for driving touch screens. Typical power

dissipation is 750μW at a 125kHz throughput rate and a

+2.7V supply. The reference voltage (VREF) can be varied

between 1V and +VCC, providing a corresponding input

voltage range of 0V to VREF. The device includes a shutdown

mode which reduces typical power dissipation to under

0.5μW. The ADS7843 is specified down to 2.7V operation.

Low power, high speed, and onboard 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 available in an

SSOP-16 package and is specified over the –40°C to +85°C

temperature range.