The AD7843 is a high performance 12-bit successive approximation ADC with a synchronous serial interface and low on resistance switches for driving touch screens. The part operates from a single 2.2V to 5.25V power supply and features throughput rates greater than 125 kSPS. The external reference applied to the AD7843 can be varied from 2.5V to 5.5V, and has an automatic attenuation feature. 2 auxiliary analog inputs can be used for temperature compensation, self-test or other applications. The AD7843 has 16-lead QSOP and TSSOP packages.
The AD7843 is a 12‑bit successive‑approximation ADC designed for resistive touch‑screen applications. It operates from a single 2.2 V to 5.25 V supply and provides up to 125 kSPS conversion rate with low power consumption, making it suitable for battery‑powered devices such as PDAs and point‑of‑sale terminals.
The device is offered in 16‑lead QSOP and TSSOP packages and includes on‑board switches, programmable 8‑bit or 12‑bit resolution, two auxiliary analog inputs, and a shutdown mode that reduces current draw to less than 1 µA. Detailed electrical specifications, timing diagrams, pin descriptions, and layout recommendations are provided throughout the document.