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TPL5111: POR = x sec?

Part Number: TPL5111

Hi people at TI,

How long is POR for the TPL5111?   How long is tRext?

I am seeing ~73.5msec initial power (Vdd) being applied to DRVn switching from low to high on a power up and I would like to know if this delay is due to POR and tRext in one shot mode?

Thanks,

Shannon

  • Hi Shannon,

    The Rest is 100ms typical as shown in page 5 of datasheet. POR time is not characterized, but you can refer to figure 6 for estimation.

    Please refer to section 7.4.3 for one shot mode description.

    Regards,
    Hao
  • Thanks for the quick response Hao,
    Just to confirm tPOR is typically ~25ms (eyeballed from Figure 6) and tRext can be up to something greater than zero up to a max of 120ms (taken from 6.5 Electrical Characteristics page 5).  So, in my case a delay of ~73ms is well within the expected range correct?
    During this time what is the state of the DRVn pin?  From a different post in the forum it is stated that DRVn is a push-pull output and looking at Figure 8 in the datasheet this pin is pulled low during the time of tPOR + tRext.  Correct?
    Thanks again,
    Shannon
  • Hi Shannon,

    tRext includes the POR delay. Figure 6 is showing the current draw during POR vs reading Rext value. The time from VDD ramp to DRV is tR_ext in all cases, typical 100ms maximum 120ms.

    During tR_ext, DRVn is LOW.

    Best Regards,