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How does this work - how does it improve THD performance? As with any transformer connected to a live wire, there will be an AC voltage common mode signal transferred by winding capacitance to...
#2: Post edited
by
Andy aka
·
2025-04-06T18:11:55Z (23 days ago)
- > _How does this work - how does it improve THD performance?_
- As with any transformer connected to a live wire, there will be an AC voltage common mode signal transferred by winding capacitance to the secondary. If you want that common-mode signal to be balanced (and hence easily cancelled by the ADCs differential input), you would use a split burden resistor.
If your application isn't that important then you would use a single burden resistor and imbalanced ADC input.
- > _How does this work - how does it improve THD performance?_
- As with any transformer connected to a live wire, there will be an AC voltage common mode signal transferred by winding capacitance to the secondary. If you want that common-mode signal to be balanced (and hence easily cancelled by the ADCs differential input), you would use a split burden resistor.
- If your application isn't that important then you would use a single burden resistor and imbalanced ADC input. That would let a certain amount of unwanted common-mode signal into your desired signal chain. That unwanted signal will be unrelated to your true CT signal hence, it's a contaminate and can be "lumped in" as a distortion artefact. Maybe that's a factor they are talking about?
#1: Initial revision
by
Andy aka
·
2025-04-02T15:17:34Z (27 days ago)
> _How does this work - how does it improve THD performance?_ As with any transformer connected to a live wire, there will be an AC voltage common mode signal transferred by winding capacitance to the secondary. If you want that common-mode signal to be balanced (and hence easily cancelled by the ADCs differential input), you would use a split burden resistor. If your application isn't that important then you would use a single burden resistor and imbalanced ADC input.