FEATURES

5-WIRE TOUCH SCREEN INTERFACE

RATIOMETRIC CONVERSION

SINGLE SUPPLY: 2V to 5V

UP TO 125kHz CONVERSION RATE

SERIAL INTERFACE

PROGRAMMABLE 8- OR 12-BIT RESOLUTION

AUXILIARY ANALOG INPUTS

FULL POWER-DOWN CONTROL

APPLICATIONS

PERSONAL DIGITAL ASSISTANTS

PORTABLE INSTRUMENTS

POINT-OF-SALES TERMINALS

PAGERS

TOUCH-SCREEN MONITORS

DESCRIPTION

The ADS7845 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 750mW 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

0.5mW. The ADS7845 is guaranteed down to 2.7V

operation.

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

the ADS7845 ideal for battery-operated systems such

as personal digital assistants with resistive touch screens

and other portable equipment. The ADS7845 is available

in a 16-lead SSOP package and is guaranteed

over the –40°C to +85°C temperature range.