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LM5001: request reference design for LM5001

TS Yang
Genius 4800 points
Part Number: LM5001
Other Parts Discussed in Thread: TPS54360, TPS54060A

Hello,

I'd like to use TI's LM5001 (Non-Automotive Version) for our IP PBX application.

Specification
- Vin: 48V
- Vout: -26V, -42V, -58V
- Iout: Max 0.7A (700mA)

1) Power Topologies
                 • Supply power to SLTC in PBX using CUK Or Inverter charge pump

2) TI Part
                 • Design of Negative Output and Multi port using LM5001
                   -. By changing the Buck Converter, the negative output state is created, and then the output voltage is synchronized to supply the load share and output with -11.6V, -23.2V, 34.8V, -46.4V, -58V.
                 • Competitors are: Linear LT3758

3) Competition PBX Reference Power rail

4) LM5001 concept (Previous developer received from TI BU.)

5) Questions

                   -. Charge pump & COUT Value
                   -. FB stage of OP input value & Compensation Value
                   -. 6 Winding design guide

thanks,

TS

  • 0
    TI__Guru* 76745 points
    Hi TS,
    Thank you for considering the LM5001. Could you please tell me the name of the TI employee who proposed the hand drawing schematic? We may have him/her to continue support on that direction. On the other hand, dDo you have to use the sepic, or you can consider a multi output flyback instead?

    Best Regards,
    Youhao Xi, System and Applications Engineering, APP-BMC-BCS, TI
  • 0
    TI__Guru 65527 points

    Hi TS,

    For further information, please see application note: Using a buck converter in an inverting buck-boost topology (SLYT286).

    www.ti.com/.../slyt286.pdf

    Regards,

    Tim

  • 0 in reply to Youhao Xi
    Genius 4800 points
    Hi Youhao,

    first of all, Thank you very much for your prompt reply.
    In fact, I think it is best to get help from someone who had previous technical support, Unfortunately, I do not know what path our predecessors received to TI's.
    Due to structural constraints and spatial reasons, sepic or multi channel flyback seems to be difficult to use.
    Is it possible to get design guide or reference design related to charge pump part, feedback and comp part, and 6 winding parts in the picture of TI employee above?

    thanks,
    TS
  • 0 in reply to Timothy Hegarty
    Genius 4800 points
    Hi Tim,

    Thank you for your prompt reply too.
    The material I need is related to the CUK topology.
    I looked for the TI webpage in my own way, but I could not find any related material. Could you share a CUK related design guide or reference design?

    thanks,
    TS
  • 0 in reply to Timothy Hegarty
    Genius 4800 points

    Hi,

    In the document titled "Stacked-Cuk" previously sent by TI, the available "Transformer" type says "VPH3-0138-R".

    The vendor of this part is "COPPER Bussmann". Please refer to this company's application note for the help of this document.

    There is an example called "SLIC Power Supply" in the last page of the document below.

    BUS_Elx_App_Notes_Versa_Pac_as_Flyback.pdf

    8561.Stacked_Cuk.pdf

    So, thank you for your review.

    TS

  • 0 in reply to TS Yang
    Genius 4800 points

    Hello TI,

    I agree that the method of configuring circuits using the LM5001 is no longer supported.
    So I ask you to choose the right product that I can use.
    1. Vin : 48V
    2. Vout : -16V
    3. Iout : 1.5A (consider derating)
    In addition,
    I wonder if the following design considerations are essential for inverting buck-boost topology.
    1. nonsynchronous : The contents on page 17 of the article you have referred to above.
    http://www.ti.com/lit/an/slyt286/slyt286.pdf
    2. peak current mode control : The contents on page 1 of the article below.
    http://www.ti.com/lit/an/slva317b/slva317b.pdf
    3. COT : constant on time
    - most of TI's buck that possible to 75V input is COT type. Does COT sustain inverting buck-boost topology?
    thanks,
    TS
  • 0 in reply to TS Yang
    TI__Guru* 76745 points
    Hi Mr. Yang,

    In order to get fast response, may I suggest you to start a new e2e thread under TPS54060A or TPS54360? Then, your question will be directed directly to the engineers supporting the buck as well as the inverting buck-boost applications.

    Best Regards,
    Youhao
  • 0 in reply to Youhao Xi
    Genius 4800 points
    Hi Youhao,
    I found the person who drawed the schematic. He is "Alan Martin" - Wide Vin Applications Wrangler.
    Can I get support from him regard of his schematic?
  • 0 in reply to TS Yang
    Genius 4800 points

    Hello,

    Below is a schematic designed by referring to Stacked-Cuk method sent from TI side.

    It seems to be a lot of errors because it was drawed with low understanding of Stacked-Cuk.

    The Op Amp. (LM258ADR) used in the schematic below is from the "Vcm include ground" property as shown in the Stacked-Cuk circuit diagram from TI.

    So, please review the above schematic.

    Regards,

    TS

  • 0 in reply to TS Yang
    Genius 4800 points
    Hello TI,
    Do you have any update for me?