AD7843ARUZ-REEL7

Overview

The AD7843ARUZ-REEL7 is a 12-bit successive approximation analog-to-digital converter (ADC) designed for resistive touch screen digitizer applications. It features a synchronous serial interface and low on-resistance switches for driving touch panels. The device operates from a single 2.2 V to 5.25 V supply, supporting throughput rates greater than 125 kSPS. It includes two auxiliary analog inputs and a shutdown mode reducing current consumption to less than 1 µA. The part is housed in a 16-lead TSSOP package.

Feature Summary

• 12-bit resolution with no missing codes guaranteed up to 11 bits
• Throughput rate exceeding 125 kSPS at 2 MHz clock
• Single supply operation from 2.2 V to 5.25 V
• Shutdown mode with maximum current consumption of 1 µA

Applications

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

Procurement Notes

Verify the REEL7 suffix indicates tape-and-reel packaging when sourcing. Confirm the ARUZ designation corresponds to the TSSOP-16 package variant. Ensure the A grade specification meets the required integral nonlinearity and offset error tolerances for the target application environment.

Selection Notes

Select this component for battery-powered systems requiring low power consumption and high-speed data acquisition. The ratiometric conversion mode eliminates errors caused by internal switch resistances, making it suitable for precise coordinate measurements. Verify that the external reference voltage range of 1 V to VCC aligns with the system design constraints.

Part Context

This part belongs to the AD7843 family of touch screen controllers manufactured by Analog Devices Inc. The AD7843 series integrates a track-and-hold amplifier, multiplexer, and ADC into a compact package. It is distinct from similar models like the AD7873, which includes an on-chip temperature sensor and voltage reference.

Replacement Considerations

The AD7873ARUZ is a functional substitute offering additional features such as an on-chip temperature sensor and internal 2.5 V reference. Both parts share the same pinout and serial interface compatibility.