The AD7796/AD7797 are complete analog front ends for high precision bridge sensor applications. They include a Σ-Δ ADC with 16-/24-bit resolution, respectively. The on-chip instrumentation amplifier has features such as low power consumption, high noise rejection, high update rate, etc.
The AD7796 and AD7797 are low‑power, 16‑/24‑bit sigma‑delta ADCs designed for bridge‑sensor applications such as weigh scales, strain gauges, and industrial process control. Each part includes an on‑chip instrumentation amplifier with a fixed gain of 128, a temperature sensor for bridge compensation, and supports both internal and external clock sources.
The document details electrical specifications, timing characteristics, pin configurations, and recommended layouts. It also includes application notes, such as a weigh‑scale implementation, and an ordering guide for the 16‑lead TSSOP package options.
| RMS Noise | 65 nV |
|---|---|
| Update Rate | 4.17 Hz to 123 Hz |
| Power Supply Voltage | 2.7 V to 5.25 V |
| Operating Temperature Range | -40 °C to +85 °C |
| Resolution | 16‑bit (AD7796) / 24‑bit (AD7797) |
| Interface | 3‑wire serial SPI/QSPI/MICROWIRE/DSP compatible |
The devices operate from 2.7 V to 5.25 V supply voltage.
They are specified for operation from –40 °C to +85 °C.
They support a 3‑wire serial interface compatible with SPI, QSPI, MICROWIRE, and DSP protocols.
The RMS noise is specified as 65 nV.