Product Summary

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.

Parametrics

ABSOLUTE MAXIMUM RATINGS(1)
+VCC to GND ........................................................................ –0.3V to +6V
Analog Inputs to GND ............................................ –0.3V to +VCC + 0.3V
Digital Inputs to GND ............................................. –0.3V to +VCC + 0.3V
Power Dissipation .......................................................................... 250mW
Maximum Junction Temperature ................................................... +150°C
Operating Temperature Range ........................................ –40°C to +85°C
Storage Temperature Range ......................................... –65°C to +150°C
Lead Temperature (soldering, 10s) ............................................... +300°C

Features

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

Diagrams