PowerPSoC® – Improving IMO Frequency Accuracy over a Wide Temperature Range

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    Question: What is the accuracy of PowerPSoC Internal Main Oscillator and how to minimize its variation with temperature drift ?



    The PowerPSoC Internal Main Oscillator (IMO) is guaranteed to maintain a frequency of 24 MHz ±4% for TJ between -40°C and 115°C, including a temperature drift. Temperature drift is a significant component of this deviation at approximately ±2%, and compensating for it significantly enhances the overall accuracy. Such a compensation algorithm offers an improved temperature drift that can become valuable when the minimal frequency drift is important, for example, in asynchronous communication applications. With the algorithm implemented in PowerPSoC applications, the IMO frequency drift is limited to approximately ± 1.0%.

    The attached document describes how to implement software compensation to minimize the temperature-dependent drift of the Internal Main Oscillator (IMO) frequency in a PowerPSoC® device.  Two Point Oscillator Trim algorithm, which improves the accuracy of the PowerPSoC’s IMO frequency across a wide temperature range is described. It explains the algorithm’s basic operation, including the generation of a dynamic trim code.

    Also attached is an example project ‘IMOTrimProject’ which implements the Two Point Oscillator Trim algorithm.