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Thread: Teensy 4.1 usb host power question

  1. #1
    Junior Member
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    Teensy 4.1 usb host power question

    Hi

    I use the teensy 4.1. I use external 5V power. So the external 5V goes to VIN. And the track from the device usb 5v is cut.
    So far so good.
    But i want to use the USB host mode. And I see there is a switch/protection TPD3S014. Since there is also a 500mA fuse, i can not supply 2A to the devices i connect to my host.
    How can i increase the power the host can supply?
    Can i simply use my 5V and connect it to the host 5V usb connector? Thus not using the VHST pin?
    Or will that not work?

    thanks
    mark

  2. #2
    Senior Member PaulStoffregen's Avatar
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    Simplest way would be to disconnect the host port VUSB pin and connect it directly (through a 2A fuse) to your 5V power supply.

    The circuitry on Teensy 4.1 is built around a 0.5 amp maximum current, which is the USB 2.0 spec.

  3. #3
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    thank you for taking the time to help.
    just to be sure : on the circuit diagram the usb host pin is named VHST right? And this is the same pin as shown on the features page where an image is shown with details for USB host. There is is named +5V. And not VHST but is the same i think.
    So my host connector goes to my own +5V and vhst remains unconnected ? That was the idea and you seem to confirm that, but now you write 'disconnect' i get doubts.
    Here is how i should connect?

    Click image for larger version. 

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  4. #4
    Senior Member+ KurtE's Avatar
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    The simplest thing is if you look at the T4.1... For example card:
    Click image for larger version. 

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    Is don't use the +5V pin marked on the 5 pin USB Host connector. Instead use your +5v power, possibly with a fuse

  5. #5
    Junior Member
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    thank you for your reply. yes that is how i understood it but i just had to be sure. in the final stage of the design i got doubts because this 5V is named VHST in the circuit. but all clear now :-)

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