Driving FET

Discussion in 'General Electronics Chat' started by gwsrf, Mar 20, 2009.

  1. gwsrf

    Thread Starter New Member

    Dec 28, 2008
    Question, When driving 2 mosfet drivers (hi-Lo IN, H-Lout for a Class "D" application), there is the need for an "FET LOGIC CONTROL" prior to the main drivers providing a sharp (narrow) square wave at the input of the mosfet drivers which eliminates the ON/OFF switching current losses at the switched points in the output stages..and possibly bolean logic is necessary to provide the proper pulse timing at the output of the drivers. Cross modulation and/or slew rate issues are not a consideration for this design, however proper LP filtering is used.

    If this is clear, I am looking for CMOS or TTL circuit or logic IC's that can provide this function. One input with four square wave outputs that can drive two drivers which then drive two half bridge mosfet coupled stages to 1100wpk into a 4 ohm transformer load. All suggestions are great.

    Thanks, gwsrf
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    When you hijack a thread by posting an unrelated question onto it, it can be quite confusing. We discourage the practice.

    This is the hijacked thread for reference - http://forum.allaboutcircuits.com/showthread.php?t=19707.

    From your specifications -
    - you simply wish a fixed frequency and pulse width? Is there some reason why the original square wave source can't feed both drive inputs?

    You might find this PDF interesting - www.irf.com/technical-info/appnotes/an-1071.pdf.

    As well as this site - http://sound.westhost.com/articles/pwm.htm
  3. mik3

    Senior Member

    Feb 4, 2008
    You will be amazed how many you can find if you make a simple search in google for 'MOSFET driver'.