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DRV8301: like EVM Buck Converter 3.3V output gives 5.6V

Part Number: DRV8301
Other Parts Discussed in Thread: TPS54160, TMS320F28027F

Hello, 

I designed DRV8301 Buck converter for gives 3.3V but I get 5.6V output. My design look pic.

Later I tried to change my DRV8301 Launchpad components to my new design again get 5.6V output.

And I reassembled the components on the EVM and it was giving 5.6V output on the EVM.

And I tried now Vsense input resistors calculation like TPS54160 and I give change output 0.2V-0.8V

How is it? 

  • Hello,

    Thanks for posting on the Motor Drives Forum!

    Have you tried using the WEBENCH Designer on TI.com?

    This tool allows you to select your exact components and fully verify the design as well as identify any potential issues.

    The webpage is here: http://www.ti.com/product/TPS54160

    Click on the Webench tool as shown:

    Regards,

    -Adam

  • Hello again, 

    I calculated my desig in there also myself calculated with TPS54160 datasheet but I didn't get 3.3V output. So I change the Vsense resistor in my design I get this results 

    R16= 31.6k recommend for 3.3V R17 =10k  I get 16.5V output. 

    R16=16.2k R17=10k I get 3.7V output.

    R16=10k, R17=10k I get 2.8V output. Your Tps54160datasheet said to 

    So it's have to be linear but this ouput's not linear . 

    Please help me this design. 

  • Hello again , 

    I calculated and than I designed . I used webench and TPS54160 datasheet. 

    I tried to my PCB's Vsesnse resistors and I get 

    R16=31.6k r17=10k Vout=16.5V

    R16=16.2k r17=10k Vout=3.7V

    R16=10k r17=10k Vout=2.98V 

    Not linear output also not like this datasheet output. 

    Please help me. 

    Best Regards 

    Aylin Ekmekçi 

    R&D Engineer.

  • Hi Aylin,

    Can you provide switch node waveforms? Is there any load? Can you try loading the output.

    What is the output voltage and vsense voltage (pin3)? 

    Regards,

    Ethan

  • Hi Ethan, 

    Load is MCU (TMS320F28027F) and the other comp.( Vsesnse voltage is near 1.4-1.3v

    I tried the other PCB's get 3.3V but I don't understand how is it?

    Also I tried the boostxl dr8301 components and output voltage 5.56V. And than I resolder boostxl pcb and get output voltage 5.56V. 

    Could you explain to me ? 

    Regards 

    Aylin

  • Hi Aylin,

    If you are seeing 3.3V on another board, it usually means the application is not the problem. Have you been trying different samples on the defected board? Can you show me switch node waveforms? 

    Regards,

    Ethan