UCD7138: Gate Driver output stage

user4005424

Part Number: UCD7138

The datasheet said the NOMS and voltage boost can help to deliver the highest source current when turning on the MOS. But I have confusion about this. Why do the NMOS in parallel with PMOS deliver higher source current? And what role does the voltage boost play? Please explain this in detail, thanks.

over 4 years ago

0 Ian Bower over 4 years ago

TI__Genius 17090 points

An expert will answer your question soon.

0 Ian Bower over 4 years ago in reply to Ian Bower

TI__Genius 17090 points

Here's what the expert said:

The NMOS is there to provide a momentary low impedance source to provide the surge of current necessary to charge the MOSFET gate capacitances. The Voltage boost is necessary because it is an NMOS device. Once the part turns on, the higher impedance PMOS is able to hold it on since MOSFETs require little to no steady state gate drive current.

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UCD7138: Gate Driver output stage