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TPSI3052: VDDP supply to VDDH before EN?

Hideki Hayashi1
Expert 6610 points
Part Number: TPSI3052

Tool/software:

Hi team,

Customer input value to understand tstart value is arroung 2[ms]: TPSI305x_calculator_1p24.xlsx

The definition of tstart is the time to VDRV = HIGH from EN=HIGH.

But customer also understands VDDH and VDDM is supplied from VDDP without EN = HIGH. so the charging time to C_DIV should be tstart.

In other words, if C_DIV is charged enough, the time to VDRV= HIGH from EN=HIGH must be t_LH_VDRV (185 us typ) in the datasheet.

Is customer understanding correct? because customer doesn't accept 2ms, require shorter.

So the question is that if Cdiv1 and Cdiv2 charged well after tstart from VDDP supplied, the delay of VDRV and EN must be t_LH_VDRV, is that correct?

Best regards,

Hayashi

  • 0
    TI__Expert 4886 points

    Hello Hayashi-san,

    Thanks for reaching out to our team on E2E. Can you please share more details about the application? When the TPSI3052-Q1 first receives power, it charges up CDIVx. So tSTART is measuring the time it takes to charge up CDIVx to the rising UVLO threshold (13 V) then turning on VDRV. 

    Hideki Hayashi1 said:
    So the question is that if Cdiv1 and Cdiv2 charged well after tstart from VDDP supplied, the delay of VDRV and EN must be t_LH_VDRV, is that correct?

    tLH_VDRV assumes VDDH steady state, meaning CDIVx is already charged up to UVLO. So tLH_VDRV is strictly measuring the delay from EN to VDRV. 

    Hideki Hayashi1 said:

    In other words, if C_DIV is charged enough, the time to VDRV= HIGH from EN=HIGH must be t_LH_VDRV (185 us typ) in the datasheet.

    Is customer understanding correct? because customer doesn't accept 2ms, require shorter.

     tSTART and tLH_VDRV are very different specs. Also, this datasheet tLH_VDRV spec is for two-wire mode. Three-wire mode is faster, which is what I see the calculator tool configured for. I see in the tool that the customer has selected CDIV1 = 100 nF and CDIV2 = 470 nF, is this correct? If the customer needs faster tSTART, then we need to increase RPXFR.

    Best regards,
    Tilden Chen

    Solid State Relays | Applications Engineer