The AD7156 is a low-power, high-sensitivity capacitance converter from Analog Devices. It has a fast response time and two capacitance input channels. It can be used in buttons and switches, proximity sensing, contactless switching, position detection, level detection, and other applications.
The AD7156 delivers a complete signal‑processing solution for capacitive sensors, offering ultralow power consumption, fast response, and adaptive environmental compensation. It operates from 1.8 V to 3.6 V and supports two independent capacitance input channels, each providing a digital detection output.
The device can be used in standalone mode with fixed settings or interfaced to a microcontroller via a 2‑wire I²C‑compatible serial interface for programmable operation. Detailed specifications, pin descriptions, timing diagrams, and application examples are provided in the datasheet.
| Supply voltage | 1.8 V to 3.6 V |
|---|---|
| Power‑down current | 2 µA typical |
| Conversion time per channel | 10 ms |
| Sensor capacitance range | 0 pF to 13 pF |
| Sensitivity | up to 3 fF |
| Operating temperature | −40 °C to +85 °C |
| Package | 10‑lead LFCSP (3 mm × 3 mm × 0.8 mm) |
| Output low voltage (V OL) | 0.4 V |
| Output high voltage (V OH) | VDD – 0.6 V |
The AD7156 operates from 1.8 V up to 3.6 V.
The device provides two independent capacitance input channels.
Each channel converts in about 10 ms.
Yes, it includes a 2‑wire I²C‑compatible serial interface for user‑defined settings.