hey guys,
so it seems that most usb devices intended for use with a laptop or desktop host have either varistors or clamp diodes on the D+ and D- lines to protect against spikes.
but my device is intended strictly for cell phones. it draws its power from the host, and the only noise it generates is from a transistor that is switching a 1.5 amp load at audio frequencies, like less than 2kHz.
i've seen guys on youtube connect their devices without these precautions and publish their schematics on the net, so maybe its ok to do so.
anybody have experience with this?
thanx, mike
so it seems that most usb devices intended for use with a laptop or desktop host have either varistors or clamp diodes on the D+ and D- lines to protect against spikes.
but my device is intended strictly for cell phones. it draws its power from the host, and the only noise it generates is from a transistor that is switching a 1.5 amp load at audio frequencies, like less than 2kHz.
i've seen guys on youtube connect their devices without these precautions and publish their schematics on the net, so maybe its ok to do so.
anybody have experience with this?
thanx, mike