Improving PWM output from common MCUs with a software Sigma-Delta stage
Year: 2025
Type: preprint
Abstract: We present an algorithm and its implementation to achieve low-noise analog output from microcontrollers (MCUs) that only feature pulse-width modulation (PWM) outputs natively. The algorithm uses Sigma-Delta modulation to dynamically adjust the lowest bit of the PWM duty cycle. Implementing the algorithm on a Raspberry Pi Pico MCU-which has two processor cores-enabled using one core for the modulation algorithm while leaving the "main" core fully available for user code. We demonstrate a 30-fold improvement in noise characteristics over plain PWM output on the same hardware.
Author: Daniel A. Wagenaar
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4408932533