Am I understanding this circuit right?

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  • caphair
    Badcaps Legend
    • Nov 2011
    • 1249
    #21
    Re: Am I understanding this circuit right?

    Originally posted by budm
    BTW, so what DCV do you have right now at S, G, and D?
    With the charger disconnected:

    S = 0v
    G = 0v
    D = 0v

    Charger connected:

    S = 5v
    G = 4.29v
    D = 5v

    So this leaves me confused, if a P-channel mosfet turns on when it sees 0v at the gate, how is this transistor turning on with 4.29v at the gate? Is that just the 5v from USB charger that's being seen since r1710 keeps the gate grounded?

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