AD7147

CapTouch™ Programmable Controller for Single-Electrode Capacitance Sensors AD7147 FEATURES www.datasheet4u.com Programmable capacitance-to-digital converter (CDC) Femtofarad resolution 13 capacitance sensor inputs 9 ms update rate, all 13 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 is compatible with the AD7142 On-chip RAM to store calibration data SPI-compatible (serial-peripheral-interface-compatible) serial interface (AD7147) I2C-compatible serial interface (AD7147-1) Separate VDRIVE level for serial interface Interrupt output and general-purpose input/output (GPIO) 24-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 FUNCTIONAL BLOCK DIAGRAM ACSHIELD VCC 8 11 GND 10 BIAS 9 CIN0 19 CIN1 20 CIN2 21 CIN3 22 CIN4 23 EXCITATION SOURCE POWER-ON RESET LOGIC CIN6 1 CIN7 2 CIN8 3 CIN9 4 CIN10 5 CIN11 6 CIN12 7 SWITCH MATRIX CIN5 24 AD7147 CALIBRATION RAM 16-BIT Σ-Δ CDC CALIBRATION ENGINE CONTROL AND DATA REGISTERS VDRIVE 12 SERIAL INTERFACE AND CONTROL LOGIC INTERRUPT AND GPIO LOGIC 18 GPIO APPLICATIONS Cell phones Personal music and multimedia players Smart handheld devices Television, A/V, and remote controls Gaming consoles Digital still cameras SDO/ SDI/ SCLK CS/ SDA ADD0 ADD1 INT Figure 1. AD7147 Bloc...