What is the frequency shift by temperature of STM32L0xx MSI(Multi-Speed Internal)?

[E-John]

"The operating temperature has an impact on the accuracy of the RC oscillators. At 25 °C, the HSI16 oscillator has an accuracy of ±1% typically, the MSI oscillator has an accuracy of ± 0.5% and the HSI48 oscillator has an accuracy of ±4%."

It is described on page 1 of AN4631 How to calibrate an STM32L0xx internal RC oscillator.

One of the Ceramic Resonator(HSE ) has Frequency Shift by Temperature +/-0.20% max.

Frequency Tolerance +/-0.50% max.

Operating Temperature Range - ℃ 20 to ℃ 

Just want to know what is the frequency shift by temperature for STM32L0xx MSI(Multi-Speed Internal)?

Thanks and Best regards,

E-John

[Danish1 · Accepted solution]

This sort of thing would normally be in the data sheet for your stm32 (unless it is so new this has not been characterised)

For example stm32l031 data sheet Rev 4* has in the "Electrical Characteristics" "Operating Conditions" "Internal Clock Source Characteristics" a table on "MSI Oscillator Characteristics" - Table 43 on pages 72-73

It says the MSI might vary by 3% over temperature, and 2.5%/V over supply-voltage.

Don't rely on these variations to be linear. Chip designers use a lot of "tricks" to eliminate variations as best they can (for example current sources that are "PTAT" (proportional to absolute temperature).

Hope this helps,

Danish

*Possibly not the most recent but that's the one I downloaded when looking at this chip to see if it was the right one for a particular project, so the table or page numbers might have changed

[Ozone]

Never heard of a "Multi-Speed Internal" oscillator, it seems new with this part - or family.

As you cited the tolerances of other oscillators, I suppose this specific one is missing from the datasheet.

Mistakes happen, so I would inquire ST directly. An perhaps ask for an updated datasheet.