AD7709 is a 16-bit differential input analog-to-digital converter with a programmable gain front end and switchable current sources that supports absolute and ratiometric measurements. It supports single 3 V and 5 V operation and has a 16-bit no missing codes peak-to-peak resolution at 20 Hz. AD7709 uses a 3-wire serial SPI, QSPI, MICROWIRE and DSP compatible Schmitt trigger SCLK interface.
The AD7709 is a 16‑bit sigma‑delta ADC with programmable gain, switchable current sources, and on‑chip rail‑to‑rail input buffers. It supports single‑supply operation at 3 V or 5 V and offers simultaneous 50 Hz and 60 Hz line‑frequency rejection. The device includes a 3‑wire serial interface compatible with SPI, QSPI, Microwire, and DSP protocols.
The document provides a functional block diagram, detailed specifications, timing characteristics, pin configuration, and application notes such as sensor measurement, temperature, pressure, and 4‑20 mA loop instrumentation. Ordering information, absolute maximum ratings, and ESD handling guidelines are also included.
| Resolution (20 mV range) | 13 bits p‑p |
|---|---|
| Resolution (2.56 V range) | 16 bits p‑p |
| Supply Voltage | Single 3 V or 5 V operation |
| Normal Power Consumption @ 3 V | 1.25 mA typ |
| Power‑down Current (crystal running) | 7 pA |
It is specified for single‑supply operation at either 3 V or 5 V.
Typical normal‑mode current consumption is 1.25 mA at 3 V.
The device draws 7 pA in power‑down mode while the 32.768 kHz crystal is running.