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PaxInstruments / labwiz-board

A development board based on the STM32 series processors specifically targeting the STM32F103RxT series.
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USB power protection #59

Closed charlespax closed 7 years ago

charlespax commented 7 years ago

What protection is needed on the USB power? Right now it's connected directly to VBUS.

robojay commented 7 years ago

Add a PTC resettable fuse between the USB connector VCC pin and VBUS.

I've used Bel Fuse 0ZCJ0050FF2G (Digi-Key 507-1802-1-ND) in similar applications.

robojay commented 7 years ago

Add a transient voltage suppressor between VUSB and ground. Something like SMBJ5.0A will work.

charlespax commented 7 years ago

I've added a PTC resettable fuse. I'm going for the 0805 package because that fits best on the board. This part seems good: http://www.digikey.com/product-detail/en/bel-fuse-inc/0ZCK0050FF2E/507-1813-2-ND/4156141 screen shot 2017-01-23 at 11 21 12 screen shot 2017-01-23 at 11 21 18

charlespax commented 7 years ago

I've added a transient voltage suppressor to USB_VBUS. It's the same as what I have on the data lines (PGB1010603).

screen shot 2017-01-23 at 11 40 29 screen shot 2017-01-23 at 11 40 47