CN0552 Capacitance-to-Digital Converter (CDC)

ADI's CN0552 solution is a 24-bit CDC with a default full-scale input range of ±4.096 pF and an extended input range of ±50 pF. The I²C serial communication interface provides a high resolution, high linearity, and high accuracy capacitance measurement.

Capacitive sensors are used in various industrial applications such as liquid level monitoring, pressure measurement, position sensing, flowmeters, humidity sensing, and many more. ΣΔ (sigma-delta) CDCs operate by exciting the unknown capacitance with a square wave and converting the resulting charge into a single-bit digital output stream. A digital filter then processes the bitstream, outputting a precise, low-noise capacitance measurement.

The CN0522 is compatible with I²C PMOD platform boards with an I/O voltage from 2.7 V to 5.5 V.

The EVAL-CN0552-PMDZ is a PMOD form-factor evaluation board for the AD7746, a high resolution, Σ-Δ CDC. The architecture features inherent high resolution (24-bit no missing codes, up to 21-bit effective resolution), high linearity (±0.01%), and high accuracy (±4 fF factory calibrated).

The EVAL-ADICUP3029 can be used as a device driver solution for controlling the EVAL-CN0552-PMDZ using the no-OS device driver.

Applications

• Instrumentation and measurement, including liquid level monitoring, pressure measurement, position sensing, flowmeters, humidity sensing, and industrial automation