Nano 33 VIN is outputting voltage?

Hardware Nano Family Nano 33 BLE
1

For the Nano 33 BLE, the box and everything online clearly says the VIN pin is use for input (...pin name is pretty self explanatory) , but I'm measuring 5v coming from it. I'd like to use this for power, but I'm nervous to use it for input when I'm already seeing output from it. Also, the 5v pin is giving nothing.

Maybe they got crossed up somehow? I find it hard to believe from a mass produced board that one of them switched inputs, but I guess it's not impossible. Anyone else ever experience this?

2

Have you looked at the schematics for the Nano 33 BLE?

3

Here you go:

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so VUSB is the 5V (nominal) from the USB

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VUSB feeds VIN via D2

So, yes - the 5V from the USB will be available at the VIN pin.

5

so does that mean if i don't have USB power i can feed in 4.5v-21v on VIN and i should expect 5v on the +5v pin?

6

If i try unplugging from the USB power source and plugging a 12v DC power source into VIN, i get 3.3v from the 3.3v pin, but still nothing from the 5v pin.

7

but still nothing from the 5v pin.

The 5V pin isn't connected to anything.
On the official nano 33 there is a jumper on the bottom that can be used to connect VUSB to 5V but I would leave alone.

8

If you want to be extra safe I would connect a diode between Vin and the power supply.

9

Again, you should look at the schematics - they're available here:

And this is the bit which shows that 5V pin:

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As @jim-p said, it's not connected to anything until you close the SJ1 link.

And if you do close that link, it connects direct to VBUS - so do not insert a USB cable while doing that!!

10

Great, I think I figured it out. Thanks for your help!

11

Good luck wih your design

12

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