
Analog Devices
GENERAL DESCRIPTION
The AD7148 is designed for use with capacitance sensors implementing functions such as buttons, scroll bars, and wheels. The sensors need only one PCB layer, enabling ultrathin applications.
FEATURES
Programmable capacitance-to-digital converter (CDC)
Femtofarad (fF) resolution
8 capacitance sensor inputs
25 ms update rate, all 8 sensor inputs
No external RC components required
Automatic conversion sequencer
On-chip automatic calibration logic
Automatic compensation for environmental changes
Automatic adaptive threshold and sensitivity levels
Register map compatible with AD7143
On-chip RAM to store calibration data
I2C-compatible serial interface
Separate VDRIVE level for serial interface
Interrupt output
16-lead, 4 mm × 4 mm LFCSP
2.6 V to 3.3 V supply voltage
Low operating current
Full power mode: 1 mA
Low power mode: 21.5 μA
APPLICATIONS
Cell phones
Personal music and multimedia players
Smart handheld devices
Television, A/V, and remote controls
Gaming consoles
Digital still cameras