GENERAL DESCRIPTION

The AD7143 is an integrated capacitance-to-digital converter (CDC) with on-chip environmental calibration for use in systems requiring a novel user input method. The AD7143 interfaces to external capacitance sensors implementing functions, such as capacitive buttons, scroll bars, and scroll wheels.

FEATURES

Programmable capacitance-to-digital converter

25 ms update rate (@ maximum sequence length)

Better than 1 fF resolution

8 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

I2C?-compatible serial interface

Separate VDRIVE level for serial interface

Interrupt output for host controller

16-lead, 4 mm x 4 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