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I don't know how to how to properly wire the two outputs of the driver IC TC4431 to the MOSFET gate.

In the datasheet, there's a test circuit diagram (@page7, FIG4-1), should I connect the outputs together to the gate pin? Since resistors might be needed to fine tune Turn-On and Turn-Off timings on the actual PCB (as mentioned in page 6), I need to consider placing spaceholder pinouts (If not needed I'll populate with 0 Ω resistors). Which is the right wiring or should the resistors be pull-up pull-down as it's common on MOSFET gates (and left unpopulated if not needed)?

schematic

simulate this circuit – Schematic created using CircuitLab

Datasheet: TC4431

winny
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Bikay
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1 Answers1

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The application diagram suggests the pins can be shorted together if need be.

enter image description here

Diodes are certainly not required.

Separate resistors may be desired for changing rise/fall times independently, or perhaps for reducing shoot-through current.[1]

If equal resistors would be used, the outputs can be shorted together and a single resistor used instead.


[1] Shoot-through is not documented on this type. At best, Fig.2-1 hints at it, but the no-load consumption could be due to internal paths as well as output shoot-through per se. And though 4.7µF is indicated (a rather large bypass capacitor, especially in relation to the ~nF typical loads shown), it might simply have been chosen out of habit rather than need. More characterization is needed to determine if shoot-through can be managed this way.

Whatever the case, shoot-through (both outputs being active, pulling up and down, simultaneously) is only a concern with respect to supply current and device dissipation, not basic device operation and function. Maybe EMI. The possibility would simply be this: even if one intends to use equal up and down resistors, supply current may be slightly lower with independent resistors, rather than shorting the pins together and using one resistor.

Tim Williams
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