GENERAL DESCRIPTION

The AD7142 and AD7142-1 are integrated capacitance-to-digital converters (CDCs) with on-chip environmental calibration for use in systems requiring a novel user input method. The AD7142 and AD7142-1 can interface to external capacitance sensors implementing functions such as capacitive buttons, scroll bars, or wheels.

FEATURES

Programmable capacitance-to-digital converter

36 ms update rate (@ maximum sequence length)

Better than 1 fF resolution

14 capacitance sensor input channels

No external RC tuning components required

Automatic conversion sequencer

On-chip automatic calibration logic

Automatic compensation for environmental changes

Automatic adaptive threshold and sensitivity levels

On-chip RAM to store calibration data

SPI?-compatible serial interface (AD7142)

I2C?-compatible serial interface (AD7142-1)

Separate VDRIVE level for serial interface

Interrupt output and GPIO

32-lead, 5 mm x 5 mm LFCSP_VQ

2.6 V to 3.6 V supply voltage

Low operating current

Full power mode: less than 1 mA

Low power mode: 50 μA

APPLICATIONS

Personal music and multimedia players

Cell phones

Digital still cameras

Smart hand-held devices

Television, A/V, and remote controls

Gaming consoles