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TPS65381A-Q1: Standby current

Part Number: TPS65381A-Q1

Hi,

My customer is confirming the input current value of VBATP pin when IGN pin is 0V.
Please see the attached file of page 1.
After IGN-OFF, the input current of VBATP pin has the change as the picture.
Time unit is seconds.

I confirmed customer circuit and output waveform.
Please see the attached file of page 2,3.
I think that TPS65381A-Q1 on customer board is standby state and there isn't current pass in circuit.
Could you confirm your test board this, please?

TPS65381A-Q1.pptx

Best regards,
Shimizu

  • Hi Shimizu-san,

     

    I'm not sure I fully understand the question, but when we do this test it is for steady state after any temperature, input voltages and charge on output capacitors has stabilized where the current consumption in standby mode (all regulator outputs disabled) and IGN = 0 V, CANWU = 0 V, 5.8 V ≤ VBAT ≤ 20 V for TJ < 85°C or 5.8 V ≤ VBAT ≤ 14 V tor TJ = 125°C.   The customer application may be having other voltages or capacitor charging left on other device pins or other slightly varying conditions as the device settles to steady state in the STANDBY state. Thus there may be some slight variation in the supply current until the device reaches steady state under the specific use case conditions.

     

    Hopefully this helps answer the question. If you need further assistance please let me know. 

     

    Best Regards,

    Scott

  • Hi Scott-san,

    Thank you for your support.
    Is your test at long time period? This issue has occurring after 67 sec from IGN_OFF in customer check.

    Best regards,
    Shimizu
  • Hi Shimizu-san,

    Our tests are at the short time frame, and steady state. The standby current is a typical value range with the idea of long term steady state since in low power modes of the modules where they are off and just looking for a wake up signal the long term average current is the relevant concept for the current consumptions. This value is in the recommended section, but it will vary depending on customer application circuitry and any transient temperature, voltage, discharge or loading over time.

    Best Regards,
    Scott
  • Hi Scott-san,

    Issue is that current consumption in standby mode (all regulator outputs disabled) is over 75uA.
    75uA is described in datasheet. and this value is max current consumption value in standby mode.
    And measurement of current consumption of customer is very simple.
    And condition is "IGN = 0 V, CANWU = 0 V, 5.8 V ? VBAT ? 20 V for TJ < 85°C".
    But over 75uA.

    Could you re-think about this issue, please?
    We request that TI measures current consumption in standby mode in long frame.

    Best regards,
    Shimizu
  • Hi Shimizu-san,

    I have tested a couple of units on the bench here and one unit has similar behavior with similar timing, the second unit has the increasing current pulse (standby current increase and decrease) after only a few seconds and is much faster in ramp up and ramp down.  This behavior is likely due to a very weak parasitic discharge path in the device.  This is the first time this has been reported or seen.  We will consider how to address this with a datasheet update, but again I would like to highlight the background of having this information was for the long term DC average current consumptions, not a relatively short peak current.

    Best Regards,

    Scott

  • Hi Scott-san,

    Thank you for your reply.

    Could you send me a document about this issue, please?
    I must explain mechanism of this issue to my customer.
    My e-mail address is "m-shimizu@fujiele.co.jp".

    Best regards,
    Shimizu