AD7879WACPZ-RL

Overview

The AD7879WACPZ-RL is a 12-bit successive approximation analog-to-digital converter (SAR ADC) designed for 4-wire resistive touch screen interfaces. It operates on a single 1.6 V to 3.6 V supply and achieves throughput rates of 105 kSPS. The device integrates low on-resistance switches, a preprocessing block with median and averaging filters, and an automatic conversion sequencer. It supports SPI serial communication and includes features such as touch-pressure measurement, temperature sensing, and configurable interrupt outputs. The component is qualified for automotive applications under AEC-Q100 standards and is housed in a 16-lead LFCSP package.

Feature Summary

• 12-bit SAR ADC with 105 kSPS throughput rate
• Integrated median and averaging filters for noise reduction
• AEC-Q100 qualified for automotive reliability
• Supports touch-pressure and internal temperature measurement

Applications

• Automotive infotainment systems
• Smart handheld devices and personal digital assistants
• Point-of-sale terminals
• Medical devices with touch interfaces

Procurement Notes

Verify the specific suffix 'ACPZ' corresponds to the LFCSP-16 package variant when sourcing. Confirm that the 'RL' designation indicates reel packaging. Ensure compatibility with the host system's voltage levels, as the device requires a 1.6 V to 3.6 V supply range. Check for current availability status, as automotive-grade components may have restricted distribution channels.

Selection Notes

Select this component for applications requiring low-power touch digitization with integrated filtering. The AD7879W uses an SPI interface; ensure the host controller supports this protocol. For I2C requirements, consider the AD7879-1W variant instead. Verify that the 16-lead LFCSP footprint fits the PCB layout constraints. The device's ability to measure touch pressure adds value for advanced gesture recognition without external sensors.

Part Context

This part belongs to the AD7879 family of touch screen controllers from Analog Devices. The 'W' suffix denotes the wider operating temperature range (-40°C to +85°C). The 'ACPZ' indicates the Lead Frame Chip Scale Package (LFCSP) form factor. The 'RL' suffix specifies the tape and reel packaging format for automated assembly.

Replacement Considerations

The AD7879WARUZ-RL serves as a pin-compatible alternative in a TSSOP-16 package. Both variants share identical electrical specifications and functionality. Selection between them depends primarily on the required surface-mount package type for the manufacturing process.