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.