AD7156BCPZ-REEL7

Overview

The AD7156BCPZ-REEL7 is a two-channel capacitance-to-digital converter (CDC) from Analog Devices, designed for ultralow power applications. It operates on a 1.8 V to 3.6 V supply with a typical current of 70 μA and features a 12-bit resolution. The device integrates an adaptive threshold algorithm to compensate for environmental variations such as temperature and humidity changes. It supports both standalone operation with fixed settings and microcontroller interfacing via a 2-wire I²C-compatible serial interface. The component is housed in a 10-lead LFCSP package measuring 3 mm × 3 mm.

Feature Summary

• Ultralow power consumption with 70 μA typical operating current and 2 μA typical power-down current
• Integrated adaptive threshold algorithm compensates for slow environmental capacitance drift
• Two independent capacitance input channels with up to 3 fF sensitivity
• I²C-compatible serial interface for programmable configuration and data readout

Applications

• Buttons and switches
• Proximity sensing
• Contactless switching
• Position detection
• Level detection

Procurement Notes

Verify the REEL7 suffix indicates tape-and-reel packaging containing 1500 units per reel. Confirm the B grade designation corresponds to the specified -40°C to +85°C industrial temperature range. Ensure the LFCSP-10 package dimensions match the 3 mm × 3 mm footprint requirements for the target PCB layout.

Selection Notes

Select this part when designing capacitive sensor interfaces requiring minimal power draw and high tolerance to parasitic ground capacitance. The internal excitation source eliminates the need for external clock generation. Consider the 10 ms conversion time per channel when determining system polling rates or response latency requirements.

Part Context

This component belongs to the AD7156 family of capacitance converters. The specific ordering code AD7156BCPZ-REEL7 identifies the B-grade temperature variant, the LFCSP-10 surface-mount package, and the reel packaging format. It serves as a complete signal processing solution for capacitive sensors without requiring complex external circuitry.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.