Customer question below
Customer needs assistance selecting the correct driver for IRF740 sized TO220 Mosfet. He has considered using the UCC37322, but is unsure.
it depends on how fast he wants the mosfet gate be driven.
and if the design uses resistor between driver and mosfet
key parameters are:
what is the intended switching speed
is turn off planned to be slower than turn on ?
what gate voltage is to be used 12V 15V ?? (IRF740 is designed to be used at 10V or higher gate drive yet below 20V)
where the gate driver voltage is being generated
UCC37322 kicks the gate
(STM's version of it )IRF740 has gate charge of max 43nC and gate capacitance of 1400pF
so with 9A of drive, tha gate is driven in about 5ns, way faster than most EMC concious designers want 400V mosfets being turned on.
in addition to the 5ns fall and rise times there is unsymmetrical delay (propagation delay) of 25/35ns so the device turns on in 40ns and off in 30ns after driver input
changes.
John,
As Eero points out, the TPS27322 will drive the IRF740, but will do so extremely quickly. Most likely you'll be better served with a smaller driver such as the TPS27424dual 4A driver, which will give you 10ns of turn-on time or the TPS2829, that will switch at a more reasonable 20ns.
Peter James Miller
IC Design
Power Management - DC/DC Solutions - Industrial & Communications DC Solutions
Member Group Technical Staff 2008