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UCC28630: Output Voltage is low 13.4V instead of 24V

Part Number: UCC28630
Other Parts Discussed in Thread: TIDA-00386, MCF8316A,

We developed a low voltage ceiling fan controller using all TI devices.

 Power Supply: TIDA-00386 Power Supply no changer, Flyback transformer is Wurth 750343068

 Motor Control: MCF8316A + MSPFR2433. This motor control section works perfectly and tested with external 24V power supply.

Problem : 

The output voltage is 13.4V instead of 24V. I had enclosed the Flyback transformer mapping connections we used.

Request help in solving this issue quickly, we have customer demo lined up and we don't want demo using external power supply. 

Thanks and Regards


  • Hi Raghu,

    Thank you for the reply on UCC28630.

    From the limited information which I have, the turns ratio definitely seems to be less in the Wurth transformer.

    Whereas the RENCO one is having 4.25:1.

    But I see some corrections even with the power stage. You should try changing the current sense resistor to see if they can help with the output voltage. Also current Lm and Rcs combination might not help with meeting the contraints. You will need to increase Lm to 340uH for a more stable operation. Please find the attached excel for calculations.


    Thank you



  • Harish, 

    Thanks For the reply. We will go through the guidelines and try to resolve the issue. If any difficulties, we will post a new query.