PWM control for DC motor

Discussion in 'The Projects Forum' started by Mass, Jul 17, 2009.

  1. Mass

    Thread Starter Member

    Apr 9, 2009
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    I'd like to make an H-bridge circuit with N-channel MOSFETS (lower Rds(on), right?) to soft start a 12V DC gearmotor using PWM over about 2 seconds at 100-300Hz (noise is OK).

    I will be using a 12V SLA battery to power the motor and circuit. The motor should draw between 20 and 30A under load.

    I've been looking at the STP80NF55-06 MOSFETs and the FAN 7392 half bridge driver. Will this 3A driver charge the MOSFETs adequately? How do I determine this?
    Qg is 142 nC typical, but this is at Vdd=44V and Id=80A.

    http://www.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMveMCOqFR6qCBeoqFZNltrYfTFqzJedcWc=

    http://www.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMvQcoNRkxSQktCY1Tobiy507SJvus5BfQI=

    If not, any suggestions for a different half bridge driver? Ideally I'd like to use a DIP device from Mouser.
     
  2. SgtWookie

    Expert

    Jul 17, 2007
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  3. Mass

    Thread Starter Member

    Apr 9, 2009
    26
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    Thanks SgtWookie. Looks like a very cool chip - I like the current sense capability, but its surface mount:eek:. At $14, I wouldn't want to push my luck by allowing brief motor stall at 60A+. I'll look into it.

    What did you think about at that FAN7392N driver? Wouldn't that give me more margin with respect to motor current by using those STP MOSFETs?
     
  4. Mass

    Thread Starter Member

    Apr 9, 2009
    26
    0
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