DocID16612 Rev 6

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AN3101

High speed internal oscillator calibration

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The frequency step size for two consecutive HSITRIMR values is not constant. It is typically

0.4% (max. 0.7%) for the monotonous range (change in the low nibble only). The frequency

step size for two consecutive HSITRIMR values which differ in the high nibble (i.e. from

0x3F to 0x40) can be up to +/- 1.5%. See the Figure 2 and the datasheet for details.

Figure 2. Example of HSI oscillator trimming steps size

Note:

This graph is given for guidance only. It is based on a device whose calibration value is

equal to 90.