Continuing my work on a half bridge driver . I faced problem of slow Turn on/off of the mosfet due to the "relatively" low output current of the IR21844 mosfet driver (1.4A source and 1.8A sink).
Using the equation I=Q/ton . I found that for the total gate charge of 2500nC (5 mosfets in parallel) switched at 20khz , with the desired Ton 0.5us . I would need 5A.
Searching for a solution lead me to IR application note 978 containing this circuit 
I was thinking if it can be simplified ( 4 transistors per output is too much space for me ) maybe something like 1 STS01DTP06 Or TC4420 on each output (HO and LO) although this is not the purpose of this IC. I am also open for other methods or suggestions that doesnot involve changing the main gate driver.
thanks in advance !
Best Answer
In your Previous Question, you show a schematic with your existing gate drive circut with a 30 ohm resistor in series with the gate driver output.
Using 15 volt gate drive and 30 ohms, your gate drive turn off current is limited to 15v/30 = 0.5 amps (initially).
You can speed up the turn off by adding a diode D2. Whether this will give you the turn off you desire, could be tested before you consider other circuitry. The additional diode does not effect the turn on (reverse biased during turn on). The diode bypasses the 30 ohm gate resistor during turnoff. This is a common practice for achieving higher turn off current.
Reducing your 30 ohm to 10 ohms would also improve turn on current.
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The TC4420 driver chip you ask about could be used to increase drive output (and sink). You will likely need more bypass (storage) capacitor to accommodate the increased peak current. You should still use the diode to improve turn off current.