An Analog-to-Digital Converter (ADC) converts analog signals into digital signals in electronic systems. The key feature of any ADC is the accuracy, or “resolution,” it offers. The higher the desired resolution, the higher the cost of the ADC.

In order to strike a balance between system cost and accuracy, higher conversion resolution is achieved by oversampling the low-resolution ADC integrated within a digital signal controller (DSC), and then processing the oversampled digital signal in software through a digital filter and decimator. This processing scheme, which adds additional bits of accuracy to the 12-bit ADC conversion in a dsPIC DSC, is explored in this application note.