The AD7142ACPZ-1500RL7 features an integrated capacitor-digital function with on-chip environmental calibrationconverter(CDC),
The AD7142 and AD7142-1 are integrated capacitance-to-digital converters (CDCs) with on-chip environmental calibration for systems requiring a new user input method. The AD7142 and AD7142-1 interface with external capacitive sensors to enable functions such as capacitive buttons, scroll bars, or scroll wheels.
The CDC has 14 input channels connected to a 16-bit, 250 kHz sigma-delta capacitance-to-digital converter through a switch matrix. The CDC senses changes in capacitance from external sensors and uses this information to log sensor activation events. External sensors can be configured as a series of buttons, a scroll bar or scroll wheel, or a combination of sensors. By programming the registers, the user has full control over the CDC settings. High-resolution sensors require less software to run on the main processor.
The AD7142 and AD7142-1 have on-chip calibration logic to handle changes in the surrounding environment. When the sensor is idle, the calibration sequence is automatically performed at successive intervals. This avoids false touches or unrecorded external sensors due to environmental changes.
The AD7142 uses an SPI-compatible serial interface
Both the AD7142 and AD7142-1 are available in 32-lead 5 mm −5 mm LFCSP_VQ packages and operate from 2.6 V~3.6 V. Operating power consumption is less than 1 mA and can be reduced to 50 μA in low-power mode (400 ms conversion interval).
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- Personal music player and multimedia player
- Cellular phones
- Digital camera
- Smart handheld devices
- TV, A/V and remote control
-Game
Features and benefits
- Programmable capacitance-to-digital converter
36 ms update rate at maximum sequence length
Resolution better than 1 fF
14 capacitive sensor input channels
No external RC tuning components are required
Automatic conversion sequencer
- On-chip auto-calibration logic
Automatically compensates for environmental changes
Adaptive thresholds and sensitivity levels
- Store calibration data with on-chip RAM
- SPI® Compatible Serial Interface (AD7142)
- I2
C-Compatible® Serial Interface (AD7142-1)
- Dedicated independent VDRIVE levels for serial interfaces
- Interrupt output and GPIO
- 32-pin, 5 mm x 5 mm LFCSP_VQ package
- Supply voltage: 2.6 V to 3.6 V
- Low operating current
Full power mode: less than 1 mA
Low-power mode: 50 μA