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TPS62134D: LPM and PSM

Hirokazu Takahashi
Expert 8420 points
Part Number: TPS62134D

Hello Support team,

Could you please support below my inquires?

Q1. Could you let me know output voltage accuracy at LPM=L and each of PWM and PSM?
Q2. Can LPM fully support PSM?
Q3. What is different in LPM from normal mode? I can find PG status and Vout value in Table 1 and 2. Does LPM have any other difference from normal mode?
Q4. Could you let me know the condition in order to change mode between PWM and PSM? Is it related with LPM?
Q5. Could you please show the actual divaton data of Iq at EN=High?

Best Regards,
Hirokazu Takahashi

  • 0
    TI__Guru**** 191445 points

    Takahashi-san,

    When LPM = L the TPS62135D output voltage is 0.7 V.  The output accuracy in that case is not specified.

    PSM should be enter any time the output current is less than one half the p-p inac inductor current.

    In LPM mode the output voltage is fixed at 0.7 V regardless of the state of VID0 and VID1.

  • 0 in reply to JohnTucker
    TI__Expert 8420 points

    Hello Tucker-san

    Thanks for your reply.
    Could you please support below question also?

    Q1. Why isn't the output accuracy at LPM defined? Could you please share the actual performance value?
    Q2. Can LPM fully support PSM?
    Q3. Could you please show the actual deviation data of Iq at EN=High?

    Best Regards,
    Hirokazu Takahashi

  • 0 in reply to Hirokazu Takahashi
    TI__Mastermind 21795 points

    Takahashi-san,

    1. Unfortunately, we do not have the output accuracy data available in LPM mode. 

    2. We tested the TPS62134D EVM in LPM mode at different output currents and input voltages and PSM was supported during this operation.

    3. The only data we have available for quiescent current variation with input voltage and temperature is Figure 1. on page 6 of datasheet.

    Regards,

    Amod

  • 0 in reply to Amod Vaze
    TI__Expert 8420 points

    Hello Amod-san

    Thanks for reaching out me.
    Could you please let me know the reason Why isn't the output accuracy at LPM defined?
    Since LPM is provided in order to reduce total power consumption and not accomodate the normal usage, will not TI define about the accuracy of output voltage?
    We want to keep 0.7V at normal condition.

    Best Regards,
    Hirokazu Takahashi

  • 0 in reply to Hirokazu Takahashi
    TI__Guru**** 191445 points

    Takahashi-san,

    We were not involved in the release of the TPS62134D, so I can only speculate on why LPM operation is not defined in the EC table.  My guess is that the EC table template is re-used fro another device that does not have this function.  A thorough search of the data archives for this product family shows that he folders for TPS62134D are missing.  They may have been lost during a prior re-organization.  I have discussed this with a knowledgeable colleague, and we both agree that the performance should be identical to the case shown in the datasheet where _LPM is asserted high.

  • 0 in reply to JohnTucker
    TI__Expert 8420 points

    Hello Tucker-san

    Thanks for reaching out.
    I could understand your situation.
    But, we want to proceed studying TPS62134D at 0.7V output condition.
    If the output accuracy at 0.7V will not be defined, we must give up it.

    I know you don't the actual deviation data and defined spec for it, could you let me know whether 0.7V output at LPM will be same mechanism as other output voltage setting?
    We want to know the possibility that the output accuracy with LPM may be same as others.

    Best Regards,
    Hirokazu Takahashi

  • 0 in reply to Hirokazu Takahashi
    TI__Guru**** 191445 points

    Takahashi-san,

    Yes, the regulation should be the same as when LPM = high.  The TPS62134D can operate in ether PSM or PWM when LPM = low, depending on the load current.