Hooking this driver up to a mosfet?

Discussion in 'General Electronics Chat' started by jdraughn, Jan 26, 2011.

  1. jdraughn

    Thread Starter Active Member

    Jan 30, 2009
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    0
    Hello everyone, I got a few questions if anyone would care to enlighten me on these mosfet driver chips. I bought a few of these. I wasn't sure if they would work ok or not, but at only 15 cents each, I figured it would be interesting to experiment with them.

    http://www.nxp.com/#/pip/pip=[pip=PMD9050D]|pp=[t=pip,i=PMD9050D][/url]

    The driver is made up of 3 transistors and a diode, but it's not a totem-pole driver. I am having a hard time understanding how exactly it's supposed to function. The only application showing it's use in a basic circuit is a time switching test circuit in the datasheet. Here is a block diagram of the chip.

    [​IMG]

    The on/off switching times listed in the datasheet are for each individual transistor and diode so I have no idea how good or bad this driver is overall for driving Mosfets.

    At the moment I am just trying to drive a brushed DC motor in a single direction using the PWM hardware from a 3.3volt PIC microcontroller. I need 10 volts to saturate the Mosfet and would like to run anywhere between 12 volts and 36 volts to the motor.

    The Mosfets I have will turn on about halfway with 3.3volts and I can run 36 volts to the motor in short bursts. With a couple of them in Parallel they don't get hot nearly as quick. I would really like to fully saturate them so they turn fully on from my 36 volt or 12 volt DC power source (The 36 volt source is a 12v and 24v power brick wired in series, the 12v is a single power brick).

    Can anyone recommend what other components I would need to drive my Mosfet with my 3.3volt PIC and this driver chip, like resistor values and placements? For 36volt and also for 12volt voltage source? This is just experimenting at my desk with no real application at the moment.

    I appreciate any wisdom anyone could offer me, thank you.
     
  2. Audioguru

    New Member

    Dec 20, 2007
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    896
    The datasheet sows a test circuit complete with parts values. Use it.
     
  3. jdraughn

    Thread Starter Active Member

    Jan 30, 2009
    33
    0
    Thanks for your reply. So all those values are valid whether i'm using 3.3v or 5v logic, and also whether or not i'm using 12v or 36v to drive the motors?
     
  4. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    You must calculate the resistor values for the supply voltage for nearly every circuit including this one.
     
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