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TPS274160: Leakage current of the ST1 to ST4 pins

Sunset
Genius 13995 points
Part Number: TPS274160

Tool/software:

Hello Team,

can you confirm the leakage current of the ST1 to ST4 pins?

Thanks,

SunSet

  • 0
    TI__Mastermind 29200 points

    Hi SunSet,

    This leakage is <1uA. Does this suffice?

    Thanks,

    Patrick

  • 0 in reply to Patrick Shalton
    TI__Genius 13995 points

    Hello Patrick,

    this may be enough. 

    On the other hand have some numbers in the datasheet may help.

    This morning I was reading the datasheet of the TPS1H000 (different part).

    The leakage is not written too. 

    The logic pin have internal pull down resistor of max 850Kohm and a low level voltage max 0.8V 

    for this, considering a <1uA makes internal pull pup not useful, probably 100K would be needed..

    Knowing the leakage is a must to have info to properly dimension the pull-up pull down resistor. 

    A number in the datasheet always help. Specifically for the TPS274160, the customer makes PLC and the environment is quite noisy. 

    They should probably not take > 100K resistor. 

    The <1uA may help to take that decision.

    Thanks,

    SunSet

  • 0 in reply to Sunset
    TI__Mastermind 29200 points

    Hi SunSet,

    To make sure, are you talking about the leakage when STx is high impedance?

    ST is just an open drain output and does not have any internal logic thresholds or pulldowns.

    100k resistor will be ok from the device-application side, but the environment noise may cause the signal on ST to fluctuate due to large pullup impedance. Does the customer have a reservation to using a smaller pulldown resistor like 10k?

    Thanks,

    Patrick

  • 0 in reply to Patrick Shalton
    TI__Genius 13995 points

    Hello Patrick,

    this is clear that it is an open drain. 

    The digital value must on the other hand be read from the MCU. 

    The input of the MCU will have limits for the 0 and 1 recognition.

    The other example with the TPS1H000 was on the input side concerning, but the decision was related to the leakage.

    For the specific question on the TPS274160 the concerning is for the input of the MCU that will read the signal. 

    The leakage will offset the voltage value the MCU can read and may end up to the undetermined digital value between 0 and 1. 

    The leakage current is always a good value to be known.

    Thanks,

    SunSet

  • 0 in reply to Sunset
    TI__Mastermind 29200 points

    Hi SunSet,

    I understand, then yes the leakage will be <10uA. TI recommends ST pullup to be 10k as per the TPS274160 data sheet.

    Thanks,

    Patrick