The AD7148 is a programmable touch controller designed specifically for single-electrode capacitance sensors. It features 500-millionths of a farad resolution, eight capacitance sensor inputs, a 25-millisecond update rate, and does not require external RC components. The AD7148 also features automatic calibration logic, environmental compensation, and automatic adaptive threshold and sensitivity levels.
The AD7148 is a programmable capacitance‑to‑digital converter designed for single‑electrode touch sensors such as buttons, scroll bars, and wheels. It provides eight sensor inputs, on‑chip automatic calibration, and a serial I²C‑compatible interface with a configurable voltage level.
The device operates from 2.6 V to 3.6 V, offers a 16‑bit resolution and ~25 ms update rate, and is available in a 16‑lead 4 mm × 4 mm LFCSP package. Detailed specifications, pin descriptions, timing diagrams, and ordering information are included.
| Update Rate | ≈25 ms |
|---|---|
| Resolution | 16 bits |
| Capacitance Sensor Input Range (CINx) | +8 pF |
| Operating Temperature Range | ‑40 °C to +85 °C |
| Package | 16‑lead 4 mm × 4 mm LFCSP |
The device provides eight capacitance sensor inputs.