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TPD4S014 standby current consumption

Alexander Goldin
Expert 1220 points
Other Parts Discussed in Thread: TPD4S014

What is the current consumption when Vbus = 0V?

May I consider it 0uA?

  • 0
    TI__Genius 12190 points

    Alexander,

    This current needs to be limited by the system, not the TPD4S014. Vbus = 0V is a short to ground, per the datasheet: "Due to the body diode of the nFET switch, if there is a short to ground on VBUS the system is expected to limit the current to VBUSOUT."

    Regards,

  • 0 in reply to Guy Yater
    Expert 1220 points
    Guy,

    Thank you for your fast answer.
    You are right.

    Probably my formulation was wrong, but I still want to clarify, what is the current in case of floating Vbus?

    Thank you in advance.
    Alexander.
  • 0 in reply to Alexander Goldin
    TI__Genius 12190 points

    The following table from the data sheet covers enabled and not:

  • 0 in reply to Guy Yater
    Expert 1220 points
    Thank you, Guy.
  • 0 in reply to Guy Yater
    Prodigy 20 points
    I just discovered this part today and had a similar question. The datasheet number for supply current seems to show current draw with zero load on VBUS_out, and 5V on VBUS (the external port). Drawing 100 uA isn't a problem if I am tryhing to charge my mobile device. What if the external port is floating, and VBUS is sitting at say 4.0 V? It doesn't seem reasonabe that this protection device is going to always draw 100 uA from my mobile device. Ideally, I would want this device to have very low current draw when I'm not using a USB port to charge my system.
  • 0 in reply to Lyle Weaver
    TI__Intellectual 1455 points
    Hi Lyle,

    The current consumption shown above is in the case there is a voltage applied to VBUS. The TPD4S014 is designed to receive power from a USB 3.0 or lower VBUS source. The current consumption is a result of needing to power the required internal components of the device, i.e oscillator, FETs, etc. In the case you mention, no power applied to VBUS port, there will be little to no current consumption form the TPD4S014 because its power source comes from the connector side, not the system side.

    I hope this helps!

    Very Respectfully,
    Brian Dempsey
  • 0 in reply to Brian Dempsey
    Prodigy 20 points

    Brian:

    Thinking about this a bit,  I can to a  different conclusion

    1)  Even if the VBUS port is floating, as long as VBUS_out pin has voltage on it, current will through through the diode in the main pass transistor back to the VBUS node and power the device   So you have the 100 uA of current draw whether anything is plugged into the USB port or not.

    2)  This is a desired feature, as you need the OVP functionality active all of the time, so that it is ready to go instantaneously when something is plugged into the USB port (and potentially causing a transient).   The OVP needs to be active and ready to catch anything that gets past the input clamping diodes.

    3)   As far as I can tell from looking at OVP ASIC datasheets, then all seem t work this way.

    regards

    Lyle

  • 0 in reply to Lyle Weaver
    TI__Intellectual 1455 points
    My mistake, I overlooked the diode on the internal FET. You are correct, there will be a current consumption in the case there is no load on the connector side, and there is a voltage on the system side.