AD7785 is a 3-channel low noise, low power, 20-bit ∑-Δ ADC with on-chip in-amp and reference from Analog Devices. It can be used for thermocouple measurements, RTD measurements, thermistor measurements, gas analysis and industrial process control.
The AD7785 is a complete analog front‑end for high‑precision measurement applications. It integrates a low‑noise 20‑bit Σ‑Δ ADC, three differential inputs, an on‑chip instrumentation amplifier, programmable gain, and a band‑gap reference. The device operates from a 2.7 V to 5.25 V supply and supports update rates from 4.17 Hz to 470 Hz.
Typical applications include thermocouple, RTD, thermistor, gas analysis, industrial process control, and portable instrumentation. The datasheet provides detailed specifications, pin descriptions, timing diagrams, and guidance on grounding, layout, and calibration.
| Power‑down current | 1 µA max |
|---|---|
| RMS noise (4.17 Hz) | 40 nV |
| Update rate range | 4.17 Hz to 470 Hz |
At 4.17 Hz the RMS noise is 40 nV.
It provides three differential analog inputs.
Yes, it supports an external differential reference voltage.