Tool/software: Linux
Hi Paul,
In my design, I'm using an external USB power switch that is controller by DRVVBUS signal. From your reply, it is clear that if the VBUS voltage drops below 4.4V for more than 100ms, the USB subsystem detects this as over-current (fault) condition. In this case, does it also de-assert the DRVVBUS signal (high to low).
If yes, how/when can this signal be tuned on again? Is this something that needs to be done in the driver or the application level?
Based on this behavior, would you recommend a USB power switch with Latch-Off feature with a time delay greater than 100ms? The switch would turn off the output (if there is OC) - resulting in the reduction of VBUS below 4.4V for more than 100ms. This would also register as over-current fault. However, the Latch-off feature would require the DRVVBUS signal to be toggled in order to re-enable the VBUS output. Is this an application level logic or something that is handled by the USB subsystem?
Thank you
Regards
Santhosh
