Tagged Questions

0
votes
0answers
96 views

Controlling USB Power with External Voltage Source

I was trying to figure out a way to add a switch to the USB +5V wire, that could be controlled with another voltage source. I was thinking about using an optocoupler + mosfet to do it. More ...
18
votes
2answers
477 views

Solution for adapting to USB current draw limits?

Summary: I'm setting up a USB-powered Li-ion charging circuit and would of course like to draw the maximum charge current possible situationally -- but also want to ensure I don't violate the USB ...
1
vote
2answers
409 views

Designing a simple automatic USB switch

I'm trying to come up with a simple way of sharing a USB peripheral between two USB hosts (computers) so that the host that is currently turned on controls the peripheral. I'm targeting low-speed ...
3
votes
1answer
797 views

Using a P-channel mosfet instead of a PNP

With the LPC1343 microcontroller (Cortex M3), there is a USB_CONNECT line which goes low when the micro is ready to connect to the computer via USB. This "soft connect" feature is implemented on the ...