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  1. #1
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    Default Voltage Question

    Just say I have a FET with a transfer characteristics chart that says that the FET wonít be transferring any current with a Gate-Source voltage up to 5V and will be effectively fully open with a Gate-Source Voltage of 10V and just say I wanted to drive the FET directly from a 5V capable PIC processor and assume that the Collector-Source voltage of the FET will be 50V ie. there will be 50 available volts on the rails to tap off.
    My current thought process would be to bias/lift the PIC up 5V with 2 voltage regulators a 10V positive one for Vdd and a -5V negative one referenced to the 10V positive reg for Vss?
    Can anyone see any issues with that or better suggestions?

    Thanks,

    Troy

  2. #2
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    Default Re: Voltage Question

    if by fet you mean mosfet that switches any appreciable current ,i very much doubt you can discharge the gate capacitance adequately that way. switching loss would be pretty high
    i would use logic level mosfet or a gate driver [TPS2829DBVR ] if its a "switching" application
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  3. #3
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    Default Re: Voltage Question

    Thanks again Richard. Much appreciated.

    Troy

  4. #4
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    Default Re: Voltage Question

    If not already committed to this particular MOSFET, try finding one with lower Gate/Source requirements. There are many with <1 volt needed to turn it on.
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  5. #5
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    Default Re: Voltage Question

    Quote Originally Posted by mpgmike View Post
    If not already committed to this particular MOSFET, try finding one with lower Gate/Source requirements. There are many with <1 volt needed to turn it on.
    I've ordered a couple of GA301A from China on Ebay which I'm hoping will be fast enough.

    Thanks,

    Troy

  6. #6
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    Default Re: Voltage Question

    GA301A ? google says thats a scr

    i would google "logic level mosfet selector" and pick something at least 100v rated and capable of switching intended current @50v



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