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PMP11287: I would like to change input range.

Masami Shimamura
Prodigy 70 points
Part Number: PMP11287
Other Parts Discussed in Thread: UCC3813-0, PMP20708

Hi, Everyone

My customer is requesting the following power supply.

 Input:

   AC: 10.2 to 126.5V 50/60Hz±5%
   DC: 10.2 to 126.5V

 Output

   DC 12V (about 70mA) or DC 5V (about 170mA)

 AC: 10.2 to 126.5V 50/60Hz±5%
 DC: 10.2 to 126.5V

I would like to modify PMP11287 circuit with reference to it, but how should I modify it ?

Best Regards,
Masami

  • 0
    TI__Expert 3640 points

    Masami san,

    As your input range is smaller than what PMP11287 has and the output power is just higher a little bit, you can simply choose MOSFET with lower voltage rating and lower Rds,on for 12V output. I was using MOSFET with ~3ohm Rds,on, you could use MOSFET with ~1ohm Rds,on and 250V voltage rating. Also, you can use smaller inrush limiting resistor R15 as your maximum input voltage is lower. Doing so will help with 10V operation.

    For 5V output version, you can't use the same buck-boost topology with UCC3813-0 controller as I used in PMP11287. This is because UCC3813-0 UVLO is higher than 5V and I was using output to provide VCC bias. I.e. 5V output is not enough to bias UCC3813-0 VCC. 

    I think it is better to go with Flyback topology similar to what I did in PMP20708 for 5V output option. However, you will still need to use external power MOSFET as the peak current at 10.2V will be too high for current TI HV FET integrated controllers.

    Regards,

    Sheng-Yang Yu 

  • 0 in reply to Sheng-yang Yu1
    Prodigy 70 points
    Hi Sheng-Yang Yu,

    Thank you for responding.

    Please let me have additional questions.
    Is it OK to understand that the MOSFET to be changed is Q2 ?
    If that is correct, I will change the device of Q2 to FQD6N25TM(On Semiconductor) from AOD3N50.
    Is my opinion correct ?
    As a supplement, Spec of FQD6N25TM is as follows,
    4.4A,250V,RDS(0n)=1.0 ohm@VGS=10V,
    ID=2.2A.

    I have few power supply design skills, so please understand the rudimentary question.

    Regards
    Masami
  • 0 in reply to Masami Shimamura
    TI__Expert 3640 points

    Yes, I meant change Q2 to FQD6N25TM.

    Regards,

    Sheng-Yang Yu

  • 0 in reply to Sheng-yang Yu1
    Prodigy 70 points
    Hi Sheng-Yang Yu,

    Thank you very much.
    I would like to try it on a prototype.

    Regards
    Masami