
Analog Devices
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