[quote user="stevenh"] I simulated the feed back circuit in TINA (see attached file). For a 416.917V input, the simulation gives a feedback value of 3.2Vpeak. That is greater than what I thought was the ADC reference voltage (=3V). That might not be an issue if the reference voltage is 3.3V; However, that would be 0.1V off. I couldn't find a TMS320F28377D control card on TI's website, so I used the F28379D control card as a reference. Is there a TMS320F28377D control card? TestFeedback.zip [/quote] To answer your question, the range used on the design is 3.3 V. You are correct there is no F28377D control card, only F28379D. You can use 3.3V as refererence by mapping the VDDIO and Vref. If you are using precision vref for ADC then you will have to use 3V. Otherwise, if 3.3V VDDIO is ok , which it is in most applications, we use 3.3 of the VDDIO as vref. Note you cannot use a precision Vref at 3.3V as ADC Ref because there can be variation which can result in violating the datasheet specification for the Vref pin. There is a switch option to select this on the F28379D , please refer to the infosheet.
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