DRV8262: OUT when IN=0

Ruixin Feng

Part Number: DRV8262

Hi team,

when tesing DRV8262EVM, I found the when IN1=0, OUT1 will be high. So it means that the top MOSFET is always on. Is that the default drive method of DRV8262? Customer want the bottom MOSFET always on and switching the top one. Can DRV8262 work this way?

Thanks!

Rayna

6 months ago

0 Ruixin Feng 6 months ago

TI__Intellectual 1825 points

We used single H bridge and PWM mode.

0 Jacob Thompson 6 months ago in reply to Ruixin Feng

TI__Mastermind 19910 points

Hey Ruixin,

See the below table - does changing your inputs to drive in Forward instead of Reverse accomplish what you want? Or can you just connect your load the other way (swap OUT1 and OUT2 connections)? Functionally swapping the connections will make the "top MOSFET" to the driver be always on

Best,

Jacob

0 Ruixin Feng 6 months ago

TI__Intellectual 1825 points

Hi Jacob,

do you mean that I got IN=0, OUT1=high because I swapped the OUT1 and OUT2? I didn't get it. The DRV8262 should always follow the table. could you pls help to clarify it? Thanks!

Rayna

0 Jacob Thompson 6 months ago in reply to Ruixin Feng

TI__Mastermind 19910 points

Hey Rayna,

I tested it on an EVM and discovered that the IN1 and IN2 signals appear to be inverted of what we expect - 100% duty cycle on IN2 results in IN2=LOW. Same for IN1, 100% IN1=LOW, and inputting 0% IN1 = HIGH.

So the device is performing correctly for the given inputs on IN1/IN2.

Best,

Jacob

0 Ruixin Feng 5 months ago in reply to Jacob Thompson

TI__Intellectual 1825 points

Hi Jacob,

It's a little bit weird. May I know why DRV8262 design like this? In general, when IN=0%, OUT= Low.

Thanks!

Rayna

0 Jacob Thompson 5 months ago in reply to Ruixin Feng

TI__Mastermind 19910 points

Hey Rayna,

This only applies to how the Web GUI functions. And I agree, it is confusion and counterintuitive. I think this is just a bug in the GUI/firmware you have discovered, we are looking into it and will likely release a new version of GUI/Firmware for the EVM that will have the "normal" control where IN=0==OUT=LOW.

Best,

Jacob

0 Ruixin Feng 5 months ago in reply to Jacob Thompson

TI__Intellectual 1825 points

Hi Jacob,

If you check the figure8-4 in datasheet 8.1.1.5, when OUT2 is switching, OU1 is high, So I'm afraid that DRV8262 is designed to operate like this. I aslo confirmed it in customer system. When IN=0, OUT = high. That's not what datasheet described. Could you pls help to check the mistake here? And pls help to double confirm the control logic of DRV8262. Thanks!

Rayna

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DRV8262: OUT when IN=0