Use the AD5292 10-bit, 1% resistor tolerance digital potentiometer and AD8221 precision instrumentation amplifier to build a low-cost, high-voltage, programmable gain instrumentation amplifier. This circuit provides 1,024 different gain settings that can be controlled via a SPI digital interface. The AD5292 has ±1% resistor tolerance performance and provides low gain error across the entire resistance range.
This document provides a detailed circuit design that combines the AD5292 10‑bit digital potentiometer with the AD8221 instrumentation amplifier. It explains the circuit function, gain settings, supply options, and layout recommendations for optimal performance.
The notes include equations for gain calculation, typical performance graphs, common variations using AD5291 or AD5293, and references to related Analog Devices tutorials for grounding, decoupling, and voltage references. This manual is written in Chinese.
| Digital potentiometer | AD5292, 10‑bit, ±1% resistance tolerance |
|---|---|
| Instrumentation amplifier | AD8221, high precision, low noise, high CMRR |
| Maximum circuit gain | 500 |
| Programmable memory locations in AD5292 | 20 |
| Supply options | +30 V single‑supply or ±15 V dual‑supply |
The maximum circuit gain is limited to 500.
The AD5292 includes 20 programmable memory locations that can be set at power‑up.
The circuit can be powered from a +30 V single supply or a ±15 V dual supply.
AD5291 (8‑bit) and AD5293 (10‑bit, no power‑up memory) can also be used.