• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Subscribers 64 subscribers
  • Views 4278 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.

PMP9219: AN-2222 LM5045 Based 720W Power Converter Utilizing Current-Doubler Topology on the Secondary

Abdul Majed
Prodigy 220 points
Other Parts Discussed in Thread: PMP9219

Hello everyone,

I am an electrical engineering student at the University of Toronto. I am trying to manufacture the PCB PMP9219 (http://www.ti.com/tool/PMP9219

problem with the bill of materials (BOM) (http://www.ti.com/lit/df/tidr351/tidr351.pdf) and the schematic(http://www.ti.com/lit/df/tidr350/tidr350.pdf). So, there two

components on the PCB design whose values, part numbers, and voltage rating are not specified on the BOM or schematic file. The two compnents are a capaitor

C42 (refer to the BOM and schematic files) and a resistor R21(refer to the BOM and schematic files). I really need to know their values and rated voltage and the part

numbers before I could manufacture the board. Please can anyone help me to specify these values so that the manufactured board works perfectly.

 

Thanks

Abdul

  • 0
    TI__Expert 7395 points
    Abdul,
    thanks for your interest in TI here. I've contacted the appropriate product group to look into your questions. You should see something from them soon.
    Regards,
    John
  • 0 in reply to John Stevens
    TI__Mastermind 34465 points
    C42 and R21 are not fitted in the reference design.
    You can adjust the control loop and optimize for C42 and R21 but they are not fitted in the PMP9219
    The pcb is laid out for 0402 size components.
    Regards,
    John Griffin
  • 0 in reply to John Griffin1
    Prodigy 220 points

    Thanks John. Can you please explain me this issue in more details? I am a beginner in PCB design. I am trying to manufacture one and learn about it to get experience.

    Thanks.

    Abdul

  • 0 in reply to Abdul Majed
    TI__Mastermind 34465 points
    Hi Abdul,
    TI has excellent seminar papers located here:
    www.ti.com/.../login.shtml
    You will find them of invaluable help in explaining the details involved in power supply design.
    Good luck,
    John
  • 0 in reply to John Griffin1
    Prodigy 220 points

    Hello John,

    Thanks a lot for your reply. Thanks for the papers' link. So, like the values of C42 and R21 will be variable? How can I explain the values and part numbers of these C42 and R21 to manufacturer so that I can order the PCB for manufacture? What to say the manufacture about them so that they understand what to do with these parts and manufacture the board with assembly without any flaw. What are the ranges of the values for C42 and R21? I need to order PCB as soon as possible. Please help me.

    Thanks
    Abdul

  • 0 in reply to Abdul Majed
    TI__Expert 3200 points
    Hi Abdul,

    Sometimes as we design our power supply, we may want to have flexibility with your PCB for Type I / Type II / Type III compensation schemes. The PMP9219 design uses Type II compensation so if this were a final production design you could just not have any reference to C42 and R21. C42 and R21 are known as DNP which means do not populate and are therefore available in case you need to use Type III compensation around the error amp. You will have the component patterns on your PCB but in the BOM you will show DNP which means the manufacturer of the PCB assembly will not populate these components. If you need to use Type III compensation, you will be glad to have the patterns on the PCB in order to solder the components. Your BOM and the gerber file database will show DNP. Sometimes you will see NU (not used) NC (no connect), etc. Our BOM needs to be updated to show DNP for item line number 18.

    As a reference on the three types of compensation schemes, look at: www.ti.com.cn/.../slva662.pdf in case you want to learn more on the types of compensation.