STM32G4 ADC Errata 2.7.2 and 2.7.3 contradict each other

[Singh.Harjit]

In document STM32G4xxxx Errata, Rev. 1: ES0430, section 2.7.2 Workaround says:

In scan conversion mode, set the input scan sequence such that two successive conversions are performed on each input. Keep the result of the first and discard the second, as only the second is affected by the input channel switch disturbance.

Section 2.7.3 Workaround says:

Perform two consecutive ADC conversions in single, scan or continuous mode. Reject the result of the first conversion and only keep the result of the second.

Help.

[Imen.D]

Hello @Singh.Harjit​ ,

The errata is correct – each workaround must be applied to errata (different conditions).

If both errata are overlapped – for example: perform conversion after long time – then we must perform 3 conversions and:

• Discard first – because long time after last conversion
• Discard third – because during third conversion is present channel switching
• Take second conversion as correct result.

I hope that is clear now for you.

Best Regards,

Imen

[Singh.Harjit]

Hi @Imen DAHMEN​ 

The info. is helpful.

The ADCs have sixteen slots for scan conversion. Let's say I trigger the ADC to do the conversion and do a single conversion per trigger. Given item 2.7.2, I must use two entries per channel I want to convert and so, I can only have eight events (maximum sequence length of 16 / 2). If so, this is a big limitation.