H-Bridge Gate Driver

Discussion in 'General Electronics Chat' started by circuitnoob89, Feb 8, 2014.

  1. circuitnoob89

    Thread Starter New Member

    Feb 8, 2014
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    Hi,

    May i know what is the purpose of the capacitor and the zener diodes is used for when connecting the driver to the H-bridge?
     
  2. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    Hi,

    May we see the schematic your referring to?
     
  3. circuitnoob89

    Thread Starter New Member

    Feb 8, 2014
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    Hi shortbus,

    Below is the attachment of my schematic. The zener diode supposed to be connected in parallel with SRC_HS1 and GATE_HS1, as well as SRC_HS2 and Gate_HS2. Could it be that the zener diode regulate the voltage for the MOSFET? But how is it achieve?

    Can i also ask there are few charge pump capacitor. i know the use is to take the input voltage and gives a increase in output voltage. However i do not understand why LR_out is connected to ground.

    Thanks!
     
    Last edited: Feb 9, 2014
  4. ronv

    AAC Fanatic!

    Nov 12, 2008
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    Get some other input, but here is my take on the data sheet.

    The zener, resistor and capacitor are there to protect the ic from transients above it's rated voltage. It clamps the voltage between gate and source to 18 volts.
    LR_out is not tied to ground but to a filter cap to ground. The cap holds the voltage constant during the peak current of charging the gate.
     
  5. crutschow

    Expert

    Mar 14, 2008
    13,027
    3,236
    The zener, resistor and capacitor also keep the MOSFET gate-source voltage from exceeding its maximum value (typically 20V).
     
  6. circuitnoob89

    Thread Starter New Member

    Feb 8, 2014
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    0
    Hi ronv,
    May i know what do you mean by :

    LR_out is not tied to ground but to a filter cap to ground. The cap holds the voltage constant during the peak current of charging the gate.

    and how does it clamps the voltage between gate and source to 18 volts?
     
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