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SMali.4
Associate
January 29, 2023
Question

I am working on STM32G030 series microcontrollers & I am using external crystal as clock source (HSE). But as per AN2867 Application note(page13) gain margin ratio should be greater than 5, But I am not able to get it above 2.9. What should I do?

  • January 29, 2023
  • 3 replies
  • 1477 views

STM32G030C8T6 has maximum critical crystal transconductance (gm) is 1.5 mA/V.

Crystal specifications that are mentioned in application note(page14) gmcrit = 0.23 mA/V with this gain margin > 5. But I checked many crystals datasheet but I am not able to find crystal with same specification.

 Available crystals have greater ESR & Load capacitance which will lower the gain margin.

What should I do? Please help with the same.

This topic has been closed for replies.

3 replies

MM..1
Chief III
January 29, 2023

HSE ... how MHz ?

SMali.4
SMali.4Author
Associate
January 29, 2023

8Mhz

AScha.3
Super User
January 29, 2023

any standard 8MHz crystal will work ;

or take a oscillator , not much more expensive today than crystal + 2x caps.

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