Teensy 3 can power a 5 volt load?

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vt91

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Teensy 3 can power a 5 volt load directly from USB?
I want to use some hall sensor switches in my projects and I want to know if 5V input on teensy digital pins is going to work.

Most affordable hall sensors with built-in Schmitt triggers work off 5 volts.
 
If you refer to the schematic, the VUSB pin connects directly to the USB power, and VIN connects to VUSB through a 500 mA PTC fuse.

So really, this question is mostly a matter of whether the USB port and cable can provide enough power. Most computers and powered hubs can output 500 mA. Unpowered USB hubs are usually limited to 100 mA per port, since they get 500 mA from upstream and distribute it to 4 devices.
 
Would Teensy 3 handle a 5V input on the digital input pin?
(A3144 hall effect switch output)
 
Teensy 3.0 inputs are NOT 5 volt tolerant. If you directly connect a low-impedance 5 volt signal, it can damage the Teensy.

Fortunately, the A3144 is an open collector output. It's powered from 5 volts, but it never drives a 5 volt signal out. It only pulls the pin to ground. It's ok to connect the A3144 output (pin 3) directly to a Teensy3 input pin. A pullup resistor is required. You should use pinMode(pin, INPUT_PULLUP) for whatever pin to connect the A3144 to. You can also use a real resistor, but connect the other side of the resistor to +3.3V, not +5V.
 
Are there any projects with similar circuit/code available out there? I want to look at one and copycat it just to be safe. Thanks.

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I built a circuit. It works surprisingly well. 5 volts power the switch directly while it grounds the input pin.
 
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What are the maximum ratings for Teesny3? What is the maximum current that can pass through it to drive a load circuit or power a small one? (This is not hall switch related.)
 
From VUSB to VIN: 500 mA

Of course, some USB sources, especially unpowered hubs, are limited to providing only 100 mA. But if the USB can source that much, Teensy3 is designed to pass 500 mA from the USB cable to VIN. There's a 500 mA PTC fuse (really, a PTC "fuse" is just a resistor that increases in value if it gets too hot from too much current flow, but "resets" as it cools back down).
 
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