AD7142ACPZ-REEL

Overview

The AD7142ACPZ-REEL is a programmable capacitance-to-digital converter (CDC) designed for touch sensor applications. It features a 16-bit sigma-delta ADC with 14 input channels and an SPI-compatible serial interface. The device operates on a 2.6 V to 3.6 V supply, consuming less than 1 mA in full power mode and 50 µA in low power mode. It includes on-chip environmental calibration logic, automatic adaptive thresholds, and a conversion sequencer. Packaged in a 32-lead LFCSP, it supports update rates up to 36 ms and offers better than 1 fF resolution.

Feature Summary

• 14-channel capacitance sensing with 16-bit sigma-delta ADC
• On-chip automatic calibration for environmental compensation
• SPI-compatible serial interface with separate VDRIVE level
• Low power consumption: <1 mA active, 50 µA low power mode

Applications

• Personal music and multimedia players
• Cell phones and smart hand-held devices
• Digital still cameras
• Television, A/V, and remote controls
• Gaming consoles

Procurement Notes

Verify the REEL suffix indicates tape-and-reel packaging when sourcing. Confirm the specific lot date code against project requirements. Ensure the host system supports the SPI protocol and provides the required 2.6 V to 3.6 V supply rails. Check for ESD precautions during handling due to the sensitive capacitive inputs.

Selection Notes

Select this part for applications requiring high-resolution capacitive touch sensing without external tuning components. Choose the AD7142 over the AD7142-1 if an SPI interface is preferred over I2C. Consider the low power mode for battery-operated devices requiring automatic wake-up capabilities. Ensure the PCB design accommodates the 32-lead LFCSP package dimensions.

Part Context

This component belongs to the AD7142 family of capacitance-to-digital converters from Analog Devices. It is functionally identical to the AD7142-1, differing only in the serial interface type (SPI vs. I2C). The device integrates a switch matrix, excitation source, and calibration engine to simplify touch sensor implementation.

Replacement Considerations

The AD7142-1 serves as a direct functional substitute if an I2C interface is acceptable instead of SPI. Other members of the AD714x family may offer different channel counts or pinouts but require software adaptation.