AD7788/AD7789 is a low power, 16-/24-bit Sigma-Delta ADC suitable for smart transmitters, battery applications, portable instrumentation, sensor measurement, temperature measurement, pressure measurement, and weigh scales. It operates from 2.5V to 5.25V power supply, with a maximum normal power consumption of 75μA and maximum power-down current of 1μA. The ADC has a resolution of 16 bits and 24 bits, RMS noise of 1.5μV, and integral nonlinearity of 3.5ppm. It supports multiple interfaces including 3-wire serial SPI, QSPI, MICROWIRE, and DSP-compatible interfaces.
The AD7788 (16‑bit) and AD7789 (24‑bit) are low‑power, low‑noise sigma‑delta analog‑to‑digital converters designed for low‑frequency measurement applications. They operate from a single 2.5 V to 5.25 V supply, draw a maximum of 75 µA in normal mode and 1 µA in power‑down, and provide a 16.6 Hz output update rate with 1.5 µV rms noise. Supported serial interfaces include 3‑wire SPI, QSPI, MICROWIRE and DSP‑compatible modes.
Typical applications include smart transmitters, battery‑powered instruments, sensor measurement, temperature and pressure sensing, weighing scales and 4‑20 mA loop systems. The devices feature an internal clock oscillator, VDD monitor channel, and differential input architecture with extensive grounding and layout recommendations to preserve high resolution.
| Resolution | 16‑bit (AD7788) / 24‑bit (AD7789) |
|---|---|
| Power‑supply voltage | 2.5 V to 5.25 V |
| Normal‑mode current | 75 µA max |
| Power‑down current | 1 µA max |
| Output update rate | 16.6 Hz (nominal) |
| RMS output noise | 1.5 µV rms typ |
| Integral nonlinearity | ±15 ppm of FSR max |
| Power‑supply rejection | 90 dB min, 100 dB typ |
The devices provide a nominal output update rate of 16.6 Hz.
In normal mode the AD7788 consumes up to 75 µA.
The ADCs support 3‑wire serial SPI®, QSPI™, MICROWIRE™, and DSP‑compatible interfaces.
They operate from 2.5 V to 5.25 V.