• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 32 subscribers
  • Views 1688 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPD3S014 directon of supply current

SEFA YILMAZ
Prodigy 20 points
Other Parts Discussed in Thread: TPD3S014, TPD3S044, TPD4S214, TPD4S014, TPD1S414, TPD1S514, TPD4S012

Hi,

I am beginner at USB interface systems. I am using a TPD3S014 with an USB - UART interface IC.

VBUS is powered by external supply in the application schematic is in datasheet (pins as IN --> 5V Source, OUT --> VBUS).  In this case, is the circuit  powered by VCC? Does VBUS need an external power to work?  What should I do if I want to use both USB bus powered and VCC, does TPD3S014 do this? Just flip the pins?(IN --> VBUS, OUT-->VCC )? Any suggestions? switchable option, another IC or ... ? Also following circuit is correct?

Thank You,

Regards

Sefa YILMAZ

  • 0
    TI__Genius 12190 points

    Sefa,

    TPD3S014 is designed to limit the current source (VBUS) on the system side (the IN Pin). It sounds like you are planning on having an OTG type VBUS, where the source can be on either the VBUS_Connector or the VBUS_System. While TPD3S014 will work in this scenario, it will not limit current from the OUT pin to the IN Pin.

    Please let me know what kind of protection you are seeking for this scheme. We have the following choices:

    We have current-limiting devices: TPD3S014, TPD3S044, TPD4S214

    and over-voltage devices: TPD1S414, TPD4S014, TPD4S214, TPD1S514,

    We also have devices that protect against ESD only: TPD4S012

    Regards,

  • 0 in reply to Guy Yater
    Prodigy 20 points

    Hi Mr. Yater,

    Thanks for your reply. I don't know exactly what OTG is. I am just planning to make a simple USB-port powered circuit. Like a MSP430 Launchpad. I want to limit (<500mA) the supply current that flows from USB port to my circuit. But the supply current flows reverse direction (from circuit's VCC to USB-port) in application schematic is in datasheet.(please look at IN - OUT Pin). Or are these just a pin names, actually supply current flows USB port to circuit's VCC?

    Am i missing something?

    Regards,

    Sefa YILMAZ

  • 0 in reply to SEFA YILMAZ
    TI__Genius 12190 points
    My suggestion is to use a current limiting switch between TPD3S014 and the VBUS rail of the system. Our current-limiting protection devices are designed to limit-current from Host to Device. Our unit could be applied in this case with OUT and IN pins reversed, but the system side pin (OUT) is only rated for +/- 2 kV. So my suggestion is to use TPD3S014 per it's data sheet and a current-limit switch between it and the system to protect against current flowing in that direction.