Introduction | Characterizing the Raspberry Pi Pico ADC

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2025-01-01 13:00:04

Compare this to the Digital IO Characteristics (Table 631); it has 18 lines! And ADCs have much more complexity and nuance than a Digital IO (however, Digital IO blocks have surprising complexity).

In this project, I will explain different ADC specifications, how they can be characterized, and the results of those tests on the PR2040.

The biggest thing is that the ADC has some significant DNL issues. It looks like those were caused by a systematic error in the capacitors for the DAC portion of the SAR ADC.

The other thing I discovered is the “Low-Noise” mode of the DC-DC converter on the Pico has more noise (see below for the performance impacts) than the high-efficiency mode.