PSoC™ 4 Voltage ADC using CSD Hardware (CSD ADC), Version 1.0
The CSD Hardware ADC component repurposes the CAPSENSE™ CSD hardware to perform voltage measurements. At its core, the CSD hardware operates as a current sensing circuit. A 1 MΩ resistor placed in series with the input converts an input voltage signal into a small current which is measured by the CSD hardware. The input voltage is calculated from this measured current and reported through an Application Programming Interface (API).
After each device reset, a simple open circuit calibration must be performed before any measurements are taken. This calibration requires starting the ADC, disconnecting all inputs using the analog mux, and making a single API call. The open circuit calibration can be called again at any time to ensure that the result is as accurate as possible. The ADC supports multiplexing input channels and two schematic macros are provided in the library to demonstrate this ability.
This component is only available when not using the CAPSENSE™ CSD block (CAPSENSE™ cannot be placed in the design).