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TMcGr.1
Visitor II
March 11, 2021
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Help choosing SPV1020 capacitor values, and a diode for D5.

  • March 11, 2021
  • 1 reply
  • 678 views

Hello,

I'm designing backup MPPTs for solar racing that's economical, and I was able to get my hands on some SPV1020 ICs, and at certain points of the AN3392 datasheet, I was having troubles figuring out certain values.

  1. For 13.5, what capacitor is cin, would it be capacitor c11 or c5, and if cin is c5, how would we go about deciding a value for c11?
  2. For 13.6, the calculated Tin=c6*r1//r2 is not approximately close to Tin=10*1/Fssw when we're using the default FSW.
    1. I used the component values in the BOM and they're still not approximately close to each other, so what are these two formulas referring to?
  3. On the PCB diagram on the AN3392 datasheet there's a diode D5 and there's no mention on the spv1020 datasheet or the demo board datasheet anywhere. What diode would be recommended?

    This topic has been closed for replies.
    Best answer by Peter BENSCH

    Please understand that the SPV1020 has been obsoleted for a long time, so that it is almost impossible to support it.

    If I remember correctly:

    1. CIN is C5 and was directly connected to the PV module, the OVP was provided by D4; seen from VIN, C11 is behind D3 and smooths the input voltage for the VCC of SPV1020; C5: 2.2-4.7µF should be fine, please keep an eye to max voltage and very low ESR
    2. Unfortunately there are no more formulas available
    3. D5 was mentioned in the schematic and is of the same type as D4: SMB36CA

    Good luck!

    When your question is answered, please close this topic by choosing Select as Best. This will help other users find that answer faster.

    /Peter

    1 reply

    P
    Peter BENSCHAnswer
    Technical Moderator
    March 12, 2021

    Please understand that the SPV1020 has been obsoleted for a long time, so that it is almost impossible to support it.

    If I remember correctly:

    1. CIN is C5 and was directly connected to the PV module, the OVP was provided by D4; seen from VIN, C11 is behind D3 and smooths the input voltage for the VCC of SPV1020; C5: 2.2-4.7µF should be fine, please keep an eye to max voltage and very low ESR
    2. Unfortunately there are no more formulas available
    3. D5 was mentioned in the schematic and is of the same type as D4: SMB36CA

    Good luck!

    When your question is answered, please close this topic by choosing Select as Best. This will help other users find that answer faster.

    /Peter

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