DRV8432 5OHM RESISTOR ON GVDD_X PINS?

Steve Dunn1

Hello,

pls see data sheet page 11 states use 5ohm resistor on GVDD-X pins for >220nF BS caps. question is do i put this resistor before or after bypass capacitor to this same pin?

also do i need a 5ohm resistor on the VDD pin as well?

-Steve

over 10 years ago

0 Ryan Kehr over 10 years ago

TI__Guru 55615 points

Steve,

The purpose of the resistor is to limit the charge current in the BS path. Since it is in series, the effect is the same whether you put it before or after the capacitor. On previous boards we have tested, we have placed it between the BS pins (of the DRV8432) and BS capacitor.

No, it is not necessary to put a resistor in series with any of the VDD, GVDD pins.

0 Steve Dunn1 over 10 years ago in reply to Ryan Kehr

Intellectual 395 points

Ryan,

can you see the attached file and tell me if this el. sch of my 5ohms is ok?

-Steve

07-MOTOR DRIVERS _ PG 15.pdf

0 Ryan Kehr over 10 years ago in reply to Steve Dunn1

TI__Guru 55615 points

Steve,

My apologies, I thought you were placing resistors in series with BS caps which is another option. I just realized the datasheet is recommending what you are showing in the schematic.

I suggest you place the resistors between the device GVDD_x pins and the decoupling capacitor. Place the capacitor as close as possible to the device pin after resistor.

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DRV8432 5OHM RESISTOR ON GVDD_X PINS?