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TPS23750EVM-108: Change to 12Volt Output

Akira Watanabe
Prodigy 10 points
Part Number: TPS23750EVM-108
Other Parts Discussed in Thread: TPS23750, TPS23755, TPS23753A, TPS23758, PMP8803, TPS23755EVM-894, TPS23753

I have TPS23750 Flyback-Converter Evaluation Board(HPA108).

This Board is 3.3V Output.　I woud like to change 12V output.

I change the following parts.

・T2　C1174-AL　→　GA3562-BL

・R19　24.3k　→　4.7k

What should I change to the following parts?

・R12,R13,R18,R20

Are there any other parts that need to be changed?

  • +1
    TI__Mastermind 21320 points

    Hello Arika Watanabe,

    The TPS23750 is an IEE802.3.af compliant part. The power levels this supports is up to 13W. We have since created two generations of parts to support this power level: TPS23753A, and TPS23755/TPS23758.

    The TPS23753A has a 12V reference design you could use:  https://www.ti.com/tool/PMP8803#technicaldocuments 

    The TPS23755 has a 12V reference design you could use: https://www.ti.com/tool/TPS23755EVM-894 

    The TPS23755 integrates the primary switching FET, enables PSR topologies and has SSFD, which all reduce the solution size. 

    I would not recommend changing parts in the HPA108. This design is a synchronous flyback, which is not the optimal solution for 12V. As you will notice in the two given designs above, the most common solution is a diode rectified flyback. I would highly encourage you to switch to this topology for a 12V output. I would highly suggest using one of these two designs. 

    If you must use the TPS23750, you can try to use it in the PMP8803, but replace the TPS23753A with the TPS23750. That would be the easiest transition. 

    Or you can look at a buck with the TPS23750: https://www.ti.com/lit/df/slvrao1/slvrao1.pdf?ts=1623862519564&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTPS23750 

    If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

     

    Regards, 

     

    Michael P.

    Applications Engineer

    Texas Instruments 

  • 0 in reply to Michael Pahl
    Prodigy 10 points

    Thank you for your answer.

    Is TPS23755EVM-894 isolate converter?

  • +1 in reply to Akira Watanabe
    TI__Mastermind 21320 points

    Hello, 

    Yes the TPS23755EVM-894 is an isolated flyback. 

    If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

     

    Regards, 

     

    Michael P.

    Applications Engineer

    Texas Instruments 

  • 0 in reply to Michael Pahl
    Prodigy 10 points

    Thank you for your answer.

    I am thinking of making a new board by referring to the evaluation board.
    As you suggested, I wanted to use TPS23755, but TPS23755 takes 50 weeks to deliver.
    With the TPS23750, you can get it right away.
    There is no choice but to use TPS23750 for this.
    By the way, isn't synchronous flyback the best solution for 12V?
    Is PMP1360 helpful? Do you sell evaluation boards?

  • +1 in reply to Akira Watanabe
    TI__Mastermind 21320 points

    Hello, 

    The TPS23750 is not recommended for new designs. We do not have any PMP1360 in stock, and since the design was created in 2007, most of the BOM is EOL. So the board cannot be built. 

    My advice is to copy the PMP8803, but replace the TPS23753A with the TPS23750. That would be the easiest transition. 

    No a synchronous flyback is not the best solution for 12V. A diode flyback is the best solution. A synchronous is better at lower voltages, such as 5v or 3.3V.

    If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

     

    Regards, 

     

    Michael P.

    Applications Engineer

    Texas Instruments 

  • 0 in reply to Michael Pahl
    Prodigy 10 points

    Thank you for your answer.

    I copy PMP8803 as advised, and replace TPS23753 with TPS23750.

    Can I think that the following pins of TPS23753 correspond to the following pins of TPS23750?
    CTL (1) → COMP (3), VB (2) → VBIAS (18), CS (3) → RSP (12)
    VC (4) → AUX (16), GATE (5) → GATE (15), RTN (6) → RTN (11)
    VSS (7) → VSS (10), VDD1 (8) VDD (9) → VDD (7)
    DEN (10) → DET (8), CLS (11) → CLASS (9), APD (12) → non
    BLNK (13) → BL (19), FRS (14) → FREQ (20)


    The TPS23753 does not have the following pins that the TPS23750 has:
    TMR (1), FB (2), SEN (4), SENP (6), RSN (13), COM (14), MODE (17)

    Is there any problem with the following processing?
    TMR: Capacitor 68nF --RTN
    FB: RTN,  SEN: RTN,  SENP: VDD
    RSN: RTN,  COM: RTN,  MODE: VBIAS

  • 0 in reply to Akira Watanabe
    TI__Mastermind 21320 points

    Hello, 

    Yes this looks correct. But connect APD to RTN. Thanks!

    If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

     

    Regards, 

     

    Michael P.

    Applications Engineer

    Texas Instruments