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UCC28710: Minimum input voltage for HV pin

Part Number: UCC28710


According to the datasheet of UCC2871x, the start-up voltage on the VDD pin (VDDon) is 21V TYP and the current comes from the HV pin.

In my understanding, the HV pin needs at least 21V or more for charging the VDD capacitor in this case.

Please provide me the minimum HV pin DC voltage needed or the minimum difference voltage between the HV pin and VDD pin for a start-up operation.

Best regards,


  • Hi Shintaro-San,

    Thank you for the query.

    The part has been tested with the HV pin supplied with 30V and it has shown to give reasonable starting current. The disadvantage is that with lower input voltage, the time taken to charge the Vdd capacitor to 21V is higher due to low start up current.