AD7843ARUZ

Overview

The AD7843ARUZ is a 12-bit successive approximation analog-to-digital converter (ADC) designed for 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 with a 2 MHz serial clock. The device features a synchronous serial interface, programmable resolution (8-bit or 12-bit), and two auxiliary analog inputs. Key specifications include a maximum normal mode current of 380 µA at 125 kSPS and a shutdown current of less than 1 µA. It utilizes an external reference voltage ranging from 1 V to VCC and is housed in a 16-lead TSSOP package.

Feature Summary

• 12-bit SAR ADC with 125 kSPS throughput rate
• Single supply operation: 2.2 V to 5.25 V
• Ratiometric conversion mode for touch screen accuracy
• Shutdown mode with <1 µA current consumption
• Two auxiliary analog inputs (IN3, IN4)

Applications

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

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm packaging type and reel specifications. Ensure the component meets RoHS compliance requirements if applicable to the target assembly process. Cross-reference the pinout and electrical characteristics with the latest datasheet revision to guarantee compatibility with existing circuit designs.

Selection Notes

Select this component for battery-powered systems requiring low power consumption and high-speed touch screen coordinate acquisition. The ratiometric mode eliminates errors caused by internal switch resistance variations. Ensure the external reference voltage is within the 1 V to VCC range and that the serial clock frequency does not exceed 2 MHz for specified performance.

Part Context

The AD7843 is part of Analog Devices' family of touch screen controllers and data converters. It integrates on-board switches for driving resistive touch screens, a track-and-hold amplifier, and a serial interface. The ARUZ designation indicates the A grade temperature range (-40°C to +85°C) and the TSSOP-16 package variant.

Replacement Considerations

Consult the manufacturer's official cross-reference guide for verified substitute part numbers. Ensure any replacement maintains compatible voltage ranges, pin configurations, and serial interface timing specifications.