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TPS7A90: MIN/MAX value of V_HYS(PG)

Genius 15940 points
Part Number: TPS7A90

Hello,

 

I have a question about PG pin hysteresis, V_HYS(PG).

For V_HYS(PG), only TYP value, 1%, is defined in the datasheet like the below.

Then are MIN and MAX values of this V_HYS(PG) available?

 

 

 

Here is the background of this question.

The threshold from PG low to PG high is defined as V_IT(PG) + V_HYS(PG).

Then because min/max values of V_HYS(PG) are not defined, we are not sure the min/max threshold values from PG low to PG high.

I believe it never happens, but no min/max definition means it could technically happen that PG never go to open drain when V_IT(PG) + V_HYS(PG) is over 100%

or PG is always open drain when V_HYS(PG) is minus %.

 

So my customer is requesting to add min/max to the datasheet.

Or could you show me something data to make clear min/max value?

  • Hi Oba,

    The hysteresis was not considered a key specification for TPS7A90 and is not a tested parameter.  As such we are not able to add min/max specifications.  Please refer to Figure 23 of the Typical Characteristics curves to see how the PG Rising and PG Falling thresholds (and therefore hysteresis) drift over temperature:

    As you can see, the PG Rising threshold will always be above PG Falling threshold.

    Very Respectfully,

    Ryan

  • Hello,

     

    Thanks for your reply.

     

    I understand we don’t test this value.

     

    But I believe we should have something.

    As I wrote in previous post, especially no MAX value mean there could technically a possibility that PG never goes open although I don’t think it will happen actually.

    Don’t you have any statistics data when you characterized this device?

    Or isn’t it possible to show me a kind of design spec etc?

     

    Regards,

    Oba

  • Hi Oba,

    The PG circuit is a simple voltage detector. PG will be logic low due to the pulldown FET until Vfb rising above the PG rising threshold. At this point the pulldown FET will be off and PG can be pulled to logic high through the external pullup resistor provided by the customer. PG will remain logic high until Vfb falls below the PG falling threshold.

    As you can see from Figure 23 of the datasheet, the PG rising threshold is relatively consistent over temperature.

    As PG hysteresis is not a specified parameter we do not have statistical data (it is not tested). The typical value of PG is 1%.

    Very Respectfully,
    Ryan