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 using 1 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 !
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 using 1 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 !