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TPS63020: TPS63020

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Replies: 8

Views: 69

Part Number: TPS63020

Hi, I utilized tps63020 with a supercapacitor in order to obtain a backup power supply. (see attached file: PMP9766 - Supercapacitor Backup Power Supply with Active Cell Balancing-).
I used more or less the same configuration visible in attached file  PMP9766 SCHEMATICS,  
It works but i don't understand why the tps63020 stop working when the capacitor  is still  3Volt charged.  i  hope The componet  should output 5 volt unless  capacitor  is 1.8 V (like datasheet say).
 it could be a problem of VTH? I tried changed  Vtrashold but the result is similar.
 if someone could help me i  would appreciate it!
Thanks 

PMP9766.pdfPMP9766_SCHEMATIC.pdf
  • Hi Marco,

    Thanks for reaching out.

    Do you meant that the supercap stops charging at 3 V instead of 5 V?

    Best regards,
    Milos

  • In reply to Milos:

    nope,  the supercap continue charging always. The real problem is  when it is fully charged and start as backup power supply.  Teorically   tps63020 works fine with  5volt output  untill input is 1.8 volt. under this voltage the output goes low.
    In may case this is not happen. the output goes low when the voltage on supercap is  about 3,5 volt and not 1.8v. 

    can it a problem of  voltage divider  VTH? 

    THANKS

  • In reply to Milos:

    nope,  the supercap continue charging always. The real problem is  when it is fully charged and start as backup power supply.  Teorically   tps63020 works fine with  5volt output  untill input is 1.8 volt. under this voltage the output goes low.
    In may case this is not happen. the output goes low when the voltage on supercap is  about 3,5 volt and not 1.8v. 

    can it a problem of  voltage divider  VTH? 

    THANKS

  • In reply to Marco Maioli:

    Hi Marco,

    This does not seem to be caused by VTH signal. VTH signal is used to stop charging the capacitor when its voltage reaches ~5.1 V, and to recharge it whenever its voltage drops to ~4.7 V. 

    1. Could you check where the EN pin of the TPS63020 is connected to? It should be connected to VIN/VC.
    2. Can you please take scope plots for VC, Vsys and VPS during the discharge from 5 V to 3.5 V?

    Best regards,
    Milos

  • In reply to Milos:

    en pin  is connected to Vin.

    for the other singlas i will send a scope plots.

  • In reply to Marco Maioli:

    Hi Marco,

    Did you have a chance to make the scope plots?

    Could you also send us the part number for the supercapacitor that you are using?

    Best regards,
    Milos

  • In reply to Milos:

     sorry, I have changed the design cause i had too problems
    thank you anyway

  • In reply to Marco Maioli:

    Hi Marco,

    Thank you for the update, and sorry to hear that.

    If you need any further help, please let us know.

    Best regards,
    Milos

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