• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Subscribers 66 subscribers
  • Views 409 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Device inquiry

Kazuhiko Hirano
Genius 15098 points
Other Parts Discussed in Thread: LM5155, LM5156, PMP22155

Hello,

My customer is looking for DC/DC converter to meet the following requirements.
Vin = 12V

Vout = -195V
Iout(max) = 0.1A

Does TI have any devices or application circuits to meet those requirements?

Best regards,

K.Hirano

  • 0
    TI__Genius 14580 points

    Hello,

    You can choose inverting buck boost converter, but HVC doesn't have suitable analog PWM controller for this application. You may ask other BU. 

  • +1 in reply to Sean Xu
    TI__Guru* 78400 points

    Hi Hirano-san,

    A couple of options to consider:

    1. You can recommend https://www.ti.com/tool/PMP22155 as Sean suggested (Thank you Sean!).  However, such design usually suits for low load current like ~10mA or so.  Your 100mA load appears to be excessive for the charge pump stage.

    2. A non-isolated flyback topology with the LM5155 or LM5156.  If the output voltage regulation requirement is not very tight, you can use a PSR flyback.

    Thanks,

    Youhao

  • 0 in reply to Youhao Xi
    TI__Genius 15098 points

    Youhao,

    Thank you for your responses.

    I am not familiar with a PSR flyback and do not know how to generate -195V from +12V using LM51 or LM516.
    If you could provide a rough example schematics and more explanations, it would be very helpful.

    Best regards,

    K.Hirano

  • 0 in reply to Kazuhiko Hirano
    Intellectual 400 points

    For such a high voltage supply, I would recommend taking a look at either a Resonant Royer type converter or other similar power supplies intended for CCFL drive.  They deliver high voltage with low output ripple and can be designed to provide your required output current level.  See the unitrode app note U-141 https://www.ti.com/lit/an/slua056/slua056.pdf?ts=1645847918658&ref_url=https%253A%252F%252Fwww.google.com%252F for an example of such a high voltage supply circuit.

  • 0 in reply to Youhao Xi
    TI__Genius 15098 points

    Youhao,

    My customer has an additional question about PMP22155.
    At PMP22155, could it be possible to get larger Iout than 10mA by changing external components?
    Or LM5155 itself has a limitation to get >10mA Iout?
    What is really a bottleneck to get more than 10mA Iout at PMP22155?

    Best regards,

    K.Hirano

  • 0 in reply to Kazuhiko Hirano
    TI__Guru* 78400 points

    Hi Hirano-san,

    First a correction:  It was Leonardo who recommended the PMP22155, and sorry  I mistook it for Sean. 

    There is no hard current limit in the PMP22155 approach, but the charge pump stage is not suitable, and less efficient, to delivery higher current.  Note that charging and discharging these capacitors each switching cycle has narrow and high magnitude current pulses.  

    I would like to recommend a flyback topology by which you can easily optimize the duty cycle by selecting an suitable transformer turns ratio, and the transformer secondary side winding can easily implement a negative output rail.  If you use PSR, namely regulating from the primary side, you can avoid the level shift circuit to monitor the negative output for feedback. 

    Please refer to our flyback design calculator at https://www.ti.com/jp/lit/zip/snvc240, with which you can choose two output rails, and non-isolated, and use  one rail to produce 10V for VCC, and the 2nd output rail can be your -190V rail by swapping the ground and rail ports, like the below configuration.

    Best Regards,

    Youhao