The AD7156 provides a complete signal processing solution for capacitive sensors with an ultra-low power converter with fast response times. Use 1.8V to 3.6V power supply. The temperature ranges from −40°C to +85°C.
Functional block diagram
The AD7156 uses Analog Devices, Inc. 's capacitor-digital converter (CDC) technology, which combines important features of the interface with real sensors such as high input sensitivity and high tolerance of input parasitic capacitance and leakage current. An integrated adaptive threshold algorithm compensates for any changes in sensor capacitance due to environmental factors such as humidity and temperature or due to changes in dielectric materials over time.
Serial Interface Timing Diagram
By default, the AD7156 operates in standalone mode with a fixed power-on setting and is instructed to detect two digital outputs. In addition, the AD7156 can be connected to the microcontroller via a serial interface, the internal registers can be programmed using user-defined Settings, and data and state can be read from the parts.
Block Diagram
