The AD7291 is an 8-channel, I2C, 12-bit SAR ADC with a temperature sensor. It features a 12-bit temperature-to-digital converter, 8 single-ended analog input channels, and an analog input range of 0V to 2.5V.
The AD7291 is a 12‑bit successive‑approximation ADC that provides eight single‑ended analog inputs, a 0 V‑to‑2.5 V input range, and an on‑chip 2.5 V reference. It operates from a single 3.3 V supply (2.8 V‑3.6 V allowed) and communicates via a standard I²C‑compatible two‑wire serial interface supporting both standard (100 kHz) and fast (400 kHz) modes. The device includes a high‑accuracy band‑gap temperature sensor with 0.25 °C resolution and an ALERT output that flags out‑of‑range conditions.
Key features include programmable channel sequencing, partial power‑down mode (12 µA max), conversion time of 3.2 µs, and a throughput of up to 22.22 kSPS. The part is supplied in a 20‑lead LFCSP package and is suited for system‑monitoring applications such as telecommunications, process control, and industrial control.
| Resolution | 12 Bits |
|---|---|
| Number of analog input channels | 8 single‑ended |
| Analog input voltage range | 0 V to 2.5 V |
| Supply voltage (VDD) | 2.8 V to 3.6 V |
| Logic supply voltage (VDRIVE) | 1.65 V to 3.6 V |
| Temperature sensor resolution | 0.25 °C |
| Maximum I²C clock frequency | 400 kHz |
| Power‑down current | 12 µA max |
| Conversion time | 3.2 µs |
| Throughput rate | 22.22 kSPS |
| Package | 20‑lead LFCSP |
The AD7291 operates from a supply voltage (VDD) of 2.8 V to 3.6 V.
When a conversion result exceeds programmed high or low limits, the ALERT pin becomes active as an out‑of‑range indicator.
The temperature sensor provides a resolution of 0.25 °C.
The device supports I²C clock frequencies up to 400 kHz in fast mode.