In Reply to: Re: USB Voltage posted by Robert Marquardt on 05/30/02 at 9:54 AM:
: : Developing a USB device using the FTDI chipset.
: : It is bus powered.
: : It looks like the motherboard is passing an unregulated VCC to the device. With no load ( in suspend for example ) VCC = 7V.
: : Typically when doing stuff it drops to 5.7V.
: : I suspect it has just killed some other devices on the board. Things got very hot and stopped working.
: : Quesion is : is this a rogue motherboard ?
: : Or should I add over voltage protection to the my design.
: I would ask that on http://www.usb.org/forums/developers/webboard.html
: Did you read the USB spec?
The spec says 5.25V max.
The real issue is are there many non-spec mboards around.
I'll try posting on the other forum as well.