FEATURES Ultralow power

2.7 V to 3.6 V, 100 μA Response time: 10 ms

Adaptive environmental compensation

2 independent capacitance input channels Sensor capacitance (CSENS) 0 pF up to 13 pF

Sensitivity to 1 fF

EMC tested

2 modes of operation

Standalone with fixed settings Interfaced to a microcontroller for user-defined settings 2 proximity detection output flags

2-wire serial interface (I2C compatible)

Operating temperature −40°C to +85°C 10-lead MSOP package

APPLICATIONS

Proximity sensing

Contactless switching

Position detection

Level detection

GENERAL DESCRIPTION

The AD7150 delivers a complete signal processing solution for capacitive proximity sensors, featuring an ultralow power converter with fast response time. The AD7151 is a single-channel, lower power alternative to the AD7150.

The AD7150 uses 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.

By default, the AD7150 operates in standalone mode using the fixed power-up settings and indicates detection on two digital outputs. Alternatively, the AD7150 can be interfaced to a microcontroller via the serial interface, the internal registers can be programmed with user-defined settings, and the data and status can be read from the part.

The AD7150 operates with a 2.7 V to 3.6 V power supply. It is specified over the temperature range of −40°C to +85°C.