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TIDA-01505: UCC28C43

Part Number: TIDA-01505
Other Parts Discussed in Thread: UCC28C43

Dear TI team,

In Application note TIDA-01505, Input voltage range is 40 V to 1 kV while output voltage range is 15V. My requirement is similar voltage variation but on output side.

Below are the application details:-

Input voltage: 12 V
Output Voltage: 200 V to 1000 V
Output Power: 10 W
Application: Unidirectional

I would like to know if above application can be used implemented using UCC28C43.

Thanks,
Shritesh

  • Hi Shritesh,

    Yes, UCC28C43 can be used for 12V input flyback. I am not sure how to generate an variable output though.

  • Hi Xun,

    Thanks a lot for quick reply.

    This application is part of very complex architecture where I do have Micro-controller. So, actual voltage and also reference voltage value is available from master micro-controller. Can we create OPAMP solution for feedback to PWM controller?

    Also, I would like to know what should be duty cycle range for PWM controller?

    I chose transformer with turns ratio as 1:50. This is giving approximately duty cycle range of 0.25 (for 200 V output) to 0.625 (for 1000 V output).

  • Hi Shritesh,

    Yes, the duty cycle can be manually changed by injecting current into FB pin. 0.25 to 0.625 is good duty cycle selection for UCC28C43. It can support up to 96% duty cycle range. As rule of thumb within 15% to 85% percent is reasonable. 

  • Hi Xun,

    Thanks a lot for your reply.

    Is there equation how duty cycle will vary based on current injected?

    Feedback signal and reference signals are available in micro-controller. How can I use these signal for current injection ? Can I use opamp based V to I converter ?

  • Hi Shirtesh,

    The injected current needs to be at similar level to the current flowing into FB pin of the IC. 

    You can use DAC of the MCU to intersect.

  • Hi Xun,

    There are few applications of PWM based FAN regulator where FB pin is grounded and  COMP pin is used to control duty of PWM IC  by PWM signal coming from micro-controller.

    I am planning to implement similar feedback loop where I will be grounding FB pin and I will control duty cycle of PWM IC with COMP pin. I will be implementing OPAMP based compensator, output feedback signal & PWM signal from microcontroller will be used to change output voltage.

    It will be really helpful to me, if have any suggestion /refence material on this.

    I tried simulations in TINA with UCC28C43 IC but did not get proper output response as expected.

    Thanks,

    Shritesh