超低功耗， 1.8 V为3mm ×3毫米， 2通道电容式转换器 Ultralow Power, 1.8 V, 3 mm × 3 mm, 2-Channel Capacitance Converter
GENERAL DESCRIPTION
The delivers a complete signal processing solution for capacitive sensors, featuring an ultralow power converter with fast response time.
The AD7156 uses an Analog Devices, Inc., capacitance-to digital converter CDC technology, which combines features important for interfacing to real sensors, such as high input sensitivity and high tolerance of both input parasitic ground capacitance and leakage current.
The integrated adaptive threshold algorithm compensates for any variations in the sensor capacitance due to environmental factors like humidity and temperature or due to changes in the
dielectric material over time.
FEATURES
Ultralow power
Power supply voltage: 1.8 V to 3.6 V
Operation power supply current: 70 μA typical
Power-down current: 2 μA typical
Fast response time
Conversion time: 10 ms per channel
Wake-up time from serial interface: 300 μs
Adaptive environmental compensation
2 capacitance input channels
Sensor capacitance CSENS: 0 pF up to 13 pF
Sensitivity up to 3 fF
2 modes of operation
Standalone with fixed settings
Interfaced to a microcontroller for user-defined settings
2 detection output flags
2-wire serial interface I2C-compatible
Operating temperature: −40°C to +85°C
10-lead LFCSP package 3 mm × 3 mm × 0.8 mm
APPLICATIONS
Buttons and switches
Proximity sensing
Contactless switching
Position detection
Level detection
Portable products