AD7879-1ACPZ-RL

Overview

The AD7879-1ACPZ-RL is a 12-bit successive approximation analog-to-digital converter (SAR ADC) designed for resistive touch screen applications. It features an I²C serial interface and operates on a single 1.6 V to 3.6 V supply with a throughput rate of 105 kSPS. The device integrates low on-resistance switches for driving 4-wire screens, a preprocessing block with median and averaging filters, and auxiliary inputs for battery monitoring or general-purpose I/O. It supports temperature measurement and touch pressure detection, with a shutdown mode consuming less than 6 μA.

Feature Summary

• 12-bit SAR ADC with 105 kSPS throughput rate
• I²C serial interface compatible with standard protocols
• Integrated median and averaging filters for noise reduction
• Auxiliary input supporting battery monitoring and GPIO functions

Applications

• Personal digital assistants
• Smart handheld devices
• Touch screen monitors
• Point-of-sale terminals
• Medical devices

Procurement Notes

Verify the specific suffix '-RL' indicates reel packaging when sourcing from distributors. Confirm the 'AD7879-1' designation ensures I²C compatibility rather than SPI. Check for moisture sensitivity levels and storage requirements prior to assembly.

Selection Notes

Select this model over the standard AD7879 if an I²C interface is required instead of SPI. Ensure the system voltage falls within the 1.6 V to 3.6 V range. Consider the LFCSP package dimensions for PCB layout constraints.

Part Context

This component belongs to the AD7879/AD7889 family of low-voltage touch screen controllers. The '-1' variant specifically denotes support for the I²C bus, distinguishing it from the SPI-only AD7879. It shares core specifications with the AD7889 but differs in package coating options.

Replacement Considerations

The AD7879ACPZ-RL serves as a functional alternative but utilizes an SPI interface instead of I²C. Designers must verify interface compatibility and pin mapping differences between the SPI and I²C versions before substitution.