HT0440 for high side gate driver in BLDC

Discussion in 'General Electronics Chat' started by punisher454, Jun 30, 2009.

  1. punisher454

    Thread Starter Member

    Jun 29, 2009
    16
    3
  2. masa6614

    Active Member

    Nov 9, 2008
    49
    0
    I've got some experience with it. Few little things i learnt from it.
    It outputs very little current, a few microAmps, so expect some slow rise times

    and even slower fall times on the output, so for a motor driver circuit, not sure

    if this is a good choice unless slow switching is okay with you.
    If you try and read the gate voltage with a multimeter or an oscillloscope, you

    may read ~5V and think that it isnt working correctly and not fully turning on the

    FET with a nice 10V gate-source voltage, but its just the impedence of the

    measuring instrument weighing it down, so you'll just have trust that it is

    actually outputing 10V. And I know the datasheet specifiys a maximum of 1mA

    current for the input signals, but no min or avg...i think i tried a couple

    hundred microamps, and that wasn't enough. So aim for the 1mA and measure the

    input voltage to make sure its the voltage you were aiming for (5V+ in my case).

    Other than that, the part seemed to be working fine, it's cheap and pretty simple

    which is why i chose it,and my application was more for a high voltage highside

    switch where speed wasnt a c
    oncern and it did the job. GOod luck
     
  3. punisher454

    Thread Starter Member

    Jun 29, 2009
    16
    3
    Thanks for the info. I have some that will be arriving tomorrow and I'll have them in testing by tuesday. If I can get them to work right I can save about 12-18 components from my board design.

    So they have very little output current, what if I tried logic level fets instead of the standard ones. Would they possibly give better performance at the lower switching voltage levels?
     
  4. punisher454

    Thread Starter Member

    Jun 29, 2009
    16
    3
    These things work really good, except for the fact that they seem to be too slow for PWM or even BLDC motor commutation.
    I can still think of a bunch of ways to use these, but not in a bldc setup.
     
  5. masa6614

    Active Member

    Nov 9, 2008
    49
    0
    Yeah, try using fets with smaller gate capacitance, that'll speed it up some. And yeah, they make for some simple solid state relay apps.
     
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