STSPIN32G4 PWM Output Jitter

[ajietb]

Created a new thread from STDRIVE101 PWM Output Jitter Inquiry here because it is a question about a completely different device.

Dear Peter,

Thank you for your explanation. That clarifies the behavior of the STDRIVE101.

I have two follow-up questions:

1. Does the STSPIN32G4 behave the same way regarding jitter?
2. Does the STSPIN32G4 use an internal clock?

I appreciate your insights.

Best regards,
Aji

[Peter BENSCH]

1. This cannot be answered in general terms because the PWM generated by the STSPIN32G4 depends on the clock used.
2. The STSPIN32G4 or the timers, which usually generate the PWM, can use internal or external clock sources.

Regards
/Peter

[ajietb]

Dear Peter,

Thank you for your response. I’d like to clarify my questions further:

1. The STSPIN32G4 consists of an STM32G431 and a motor driver. My question specifically concerns the motor driver section. For example, if the PWM generated by the STM32G431 timer has no jitter at all, would the output from the motor driver also be completely jitter-free?

2. My question is about the motor driver itself, not the MCU. Some motor driver ICs from other manufacturers include an internal clock, which can introduce jitter in the output. Does the motor driver section of the STSPIN32G4 have an internal clock that could affect the output in a similar way?

Best regards,
Aji

[Peter BENSCH]

1. Yes, if the PWM generated by the STM32G431 timer has no jitter at all, the output of the motor driver is also completely jitter-free, because the gate driver is very comparable to the one in STDRIVE101.
2. Like the STM32G431, the STSPIN32G4 can work with an external clock, the PLL or the internal HSI. If you use the clock from HSE directly, i.e. without PLL, no jitter should occur. In the data sheet of the STM32G431 you will find information about the jitter of both clock sources, which are less than 150ps/250ps (HSI48) or 29ps (PLL).
   The question is whether you are bothered by this small jitter in the motor control?

Regards
/Peter

[ajietb]

Hi Peter,

No, that level of jitter is already small enough and does not pose any issue. Thank you for addressing my concerns so clearly. I really appreciate your detailed explanation.

Best regards,
Aji