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Miyuki
Associate II
April 12, 2024
Solved

Does any line have 20 differential channels with PGA? Any parametric search to such thing?

Hi, 

does have any line of STM32 possibility to measure 20 differential channels with voltages of about 100-150mV. So PGA will be welcome. 
In classic parametric search, I cannot find such parameters.

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Peter BENSCH
Peter BENSCHBest answer
ST Technical Moderator
April 12, 2024

Ah, sorry, I should have read your requirements more carefully. Correct, the PGA cannot process a differential signal.

I did a quick check and was able to assign 18 differential ADC channels to packages with 128 pins, you might be able to get 20 with a little rearranging. However, as the 150mV signals are somewhat small, in my opinion differential opamps or PGAs would have to be connected externally.

Regards
/Peter

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3 replies

Peter BENSCH
ST Technical Moderator
April 12, 2024

Yes, just have a look at the family of STM32G4 providing up to 5 independent ADC with PGA.

Hope that helps?

Regards
/Peter

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Miyuki
MiyukiAuthor
Associate II
April 12, 2024

The G4 series cannot do it. They can use OPAMS as PGA but just with single ended signal (and have just a limited number of inputs to them). It has no way to convert differential signals to single ended ADC. And ADCs itself are just single ended without a gain stage. 

Peter BENSCH
Peter BENSCHBest answer
ST Technical Moderator
April 12, 2024

Ah, sorry, I should have read your requirements more carefully. Correct, the PGA cannot process a differential signal.

I did a quick check and was able to assign 18 differential ADC channels to packages with 128 pins, you might be able to get 20 with a little rearranging. However, as the 150mV signals are somewhat small, in my opinion differential opamps or PGAs would have to be connected externally.

Regards
/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.