AD7879WACPZ-R5

Overview

The AD7879WACPZ-R5 is a 12-bit successive approximation analog-to-digital converter (SAR ADC) designed for 4-wire resistive touch screen interfaces. Operating on a single 1.6 V to 3.6 V supply, it achieves throughput rates of 105 kSPS with a shutdown current of less than 6 µA. The device integrates low on-resistance switches for driving touch screens and includes preprocessing blocks featuring median and averaging filters to reduce noise. It supports SPI serial communication and offers programmable conversion parameters, an auxiliary analog input/battery monitor, and temperature measurement capabilities.

Feature Summary

• 12-bit SAR ADC with 105 kSPS throughput rate
• Integrated median and averaging filters for noise reduction
• Low power operation: 1.6 V to 3.6 V supply, <6 µA in shutdown mode
• On-chip switches with low on-resistance for 4-wire touch screens
• Programmable auxiliary input, battery monitor, and GPIO

Applications

• Automotive applications
• Smart handheld devices
• Touch screen monitors
• Point-of-sale terminals
• Medical devices

Procurement Notes

Verify the specific package variant against the datasheet. The 'ACPZ' suffix indicates the LFCSP package, while the 'W' denotes the wider operating temperature range (-40°C to +85°C). Confirm that the SPI interface version matches the system design, as the I2C version uses a different part number (AD7879-1W). Ensure the reel quantity aligns with manufacturing requirements.

Selection Notes

Select this component when a low-voltage, high-speed touch screen controller is required. The AD7879W is suitable for systems needing ratiometric or single-ended touch measurements. Consider the integrated filters if the environment has significant LCD noise. Verify that the 1.6 V minimum supply voltage meets the system's power rail specifications.

Part Context

This part belongs to the AD7879 family of touch screen controllers from Analog Devices. The AD7879W variant specifically supports the SPI interface, whereas the AD7879-1W supports I2C. Both share similar electrical characteristics but differ in pinout and serial protocol compatibility. The LFCSP package provides a compact footprint for space-constrained designs.

Replacement Considerations

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