DRV8332: Resistors at the application diagram

Muharrem Atalay

Prodigy 20 points

Part Number: DRV8332

Hello,

I am newbie at motor drivers,

I want to design BLDC driver via 8332.

I checked the application diagram at the data sheet.

I need help about resistors.

There is a 3.3 ohm resistor at PVDD source

and

There is a 1 ohm resistor between AGND and GND

What are the purpose of these resistors and which package(watt) should i use?

I am going to supply 48V.

Motor RMS 6A

Motor Peak 9A

resistor watt of 3.3 ohm PVDD = V2/R = 48*48/3,3 = 698W???

And one more question:

https://katalog.we-online.de/pbs/datasheet/742792903.pdf

Is this ferrite bead suitable for my design. In the datasheet, it says "10 ohm or higher at 10mhz or below". It looks suitable but I want to be sure.

over 4 years ago

0 Adam Sidelsky over 4 years ago

TI__Guru 61380 points

Muharrem,

Your power equation is only valid if the total current or voltage is dropped by the resistor. The reason for this 3.3 ohm resistor is to filter the PVDD node, only a small noise current will travel through the resistor, a small 0.25 or smaller resistor is fine here.

The 1 ohm between the GND pins is also for noise isolation, just a little bit of separation is helpful here so we put 1 ohm.

I cannot say for sure about the inductor but it looks fine to me.

Regards,

-Adam

0 Muharrem Atalay over 4 years ago in reply to Adam Sidelsky

Prodigy 20 points

I got it. Thanks.

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DRV8332: Resistors at the application diagram