The AD7781 is a complete front‑end solution for bridge sensor products such as weigh scales, strain gauges, and pressure sensors. It integrates a 20‑bit sigma‑delta ADC, a programmable gain amplifier, an internal clock oscillator, and a bridge power‑down switch, operating from 2.7 V to 5.25 V.
The device offers pin‑programmable filter response (10 Hz or 16.7 Hz update rates), gain selection (1 or 128), and a low‑power consumption of 115 µA typical at gain = 1. All functions are controlled via dedicated pins, and eight status bits are appended to each conversion for data integrity verification.
| Resolution | 20 bits |
|---|---|
| Typical Current (Gain = 1) | 115 µA |
| Update Rate Options | 10 Hz or 16.7 Hz |
| Gain Options | 1 or 128 |
| Operating Temperature Range | ‑40 °C to +105 °C |
Typical current consumption is 115 µA when the gain is set to 1.
The filter can be set to either 10 Hz or 16.7 Hz update rate via a pin‑selectable option.
Yes, the device has a power‑down mode that disables the bridge and the ADC to reduce battery consumption.