AD7873ARQZ-REEL7

Overview

The AD7873ARQZ-REEL7 is a 12-bit successive approximation analog-to-digital converter (ADC) designed for resistive touch screen digitizer applications. It operates from a single 2.2 V to 5.25 V supply and supports throughput rates up to 125 kSPS. The device integrates low on-resistance switches, an on-chip 2.5 V reference, and a temperature sensor (-40°C to +85°C). Key features include direct battery measurement (0 V to 6 V), touch pressure sensing, and programmable resolution. It utilizes a high-speed synchronous serial interface and offers a shutdown mode with current consumption below 1 µA.

Feature Summary

• 12-bit SAR ADC with 125 kSPS throughput rate
• Integrated 2.5 V reference and -40°C to +85°C temperature sensor
• Direct battery monitor input (0 V to 6 V) and touch pressure measurement
• High-speed synchronous serial interface with 1 µA shutdown current

Applications

• Personal digital assistants
• Smart hand-held devices
• Touch screen monitors
• Point-of-sale terminals
• Pagers

Procurement Notes

Verify the REEL7 suffix indicates tape-and-reel packaging rather than tube packaging when sourcing components. Confirm the specific grade (A or B version) matches system requirements for integral nonlinearity and offset error specifications. Ensure the QSOP-16 package form factor aligns with the target PCB footprint and thermal management strategy.

Selection Notes

Select this component for battery-powered systems requiring integrated touch screen driving switches and monitoring capabilities. The internal 2.5 V reference simplifies design by eliminating external reference components, though an external reference between 1 V and VCC is supported. Consider the 125 kSPS speed and 12-bit resolution for applications needing precise coordinate tracking and pressure sensitivity.

Part Context

The AD7873 belongs to the Analog Devices AD7873 family of touch screen controllers. Variants such as the AD7873BRQZ and AD7873ARUZ share similar core functionalities but differ in package types like TSSOP or LFCSP. The ARQZ designation specifically identifies the 16-lead Quarter Size Outline Package (QSOP) variant within this product line.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Designers should evaluate other members of the AD7873 family or compatible ADS7846 series devices based on pin compatibility and electrical specification overlap.