This application note describes briefly important factors for the usage of the PCF8883 and PCA8886 sensor devices.
This document provides an application note for the NXP PCF8883 and PCA8886 devices, which are capacitive proximity switches featuring auto-calibration. It explains how to define mechanical outlines and desired switching distances to optimize performance.
The guide details the dimensioning of key components including Rc, Ccpc, and Co_in to adjust switch sensitivity, calibration, and speed. It also covers factors influencing sensitivity such as approach speed, sensor area, material permittivity, and coupling with ground.
The total capacitance on the input must be lower than 60 pF to ensure the control loop works correctly.
The lowest value allowed for the Rg resistance is 20 kOhm.
The typical value for Ccpc used as a starting point is 470 nF.