Shoot through a problem with gate drive IC?

[cupoftea]

Hi,
UCC27532 has a separate pull up and pull down fet......this is so on or off slew rate can get individual control...but can we just tie the pull up and pull down node together?....or will this result in shoot-through?
Datasheet doesnt say.
UCC27532

https://www.ti.com/lit/ds/symlink/ucc27532.pdf?HQS=dis-dk-null-digikeymode-dsf-pf-null-wwe&ts=1654100031220

Also, UCC27532 has a weak pullup on EN pin of 500k to 5v8 internal......is it best to tie it to Vdd with say 10k to reduce noise issues?

 

[KlausST]

Hi,

can we just tie the pull up and pull down node together?

Just read the datasheet carefully (or use the PDF search function)

* Datasheet, Page4, ELECTRICAL CHARACTERISTICS, default condition: OUTH and OUTL are tied together.
* Datasheet, Page5, Figure 1: OUTH tied to OUTL
* Datasheet, Page8, INPUT/OUTPUT LOGIC TRUTH TABLE: OUTH and OUTL pins tied together

If they do this in the datasheet, it should be no problem.

***
But why use a MOSFET driver with this feature .. but don´t use it?

Klaus

 

[dick_freebird]

In my few products' worth of experience doing MOSFET drivers,
I always would minimize (not to say eliminate) shoot-through
in the commoned-output configuration. Eliminating all of it
would add too much to prop delay, allowing too much will ruin
dynamic Icc and overall power-train efficiency. A modest
shoot-through (providing that features are sized for the
time averaged current density, etc.) can be tolerated as far
as product reliability goes.

The point of split outputs is to tailor totem-poled external
FET gate waveforms to prevent shoot-through -there-. Which
is likely more variable and more painful.