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Original question:

DRV2700: DRV2700EVM-HV500 - High current draw at certain output voltage

DRV2700: Flyback Configuration - Comparator

Toby Lane
Prodigy 60 points
Part Number: DRV2700

Tool/software:

Hello,

I am currently looking at the DRV2700 in flyback configuration, specifically the schematic for DRV2700EVM-HV500. The documentation suggests that the MOSFET must be driven from a comparator, however the design uses OPA2376AIYZD, which is an op amp. I presume that this was chosen because an op amp was already being used in the active low pass filter for the PWM so the other channel was used for this. Can anyone confirm that U3A is definitely operating in open loop? i.e. VGate is only ever +5V or 0V?

Thanks.

  • 0
    TI__Genius 10542 points

    Hi Toby,

    The OpAmp is being used as a comparator. A subtle piece of information is that the Rext = Vref = 1.35V. The Vpulldown voltage is being compared to 1.35V. Yes, U3A is operating in open loop and pulling the gate high (VDRV) or low (0V).