SLLSFW6 March 2024 ISOUSB211-Q1
ADVANCE INFORMATION
When in Full-speed (FS) and Low-speed (LS) modes, disconnection of a peripheral is indicated when the host/hub is not driving any signal on the upstream side, and when the downstream bus is in the SE0 state ( Both DD+ and DD- are below the VILthreshold) for a time period higher than TDDIS. Upon disconnect detection in FS and LS modes, the ISOUSB211-Q1 device removes the pull-up resistor from the upstream side, thus allowing the upstream UD+ and UD- lines to discharge to zero. The ISOUSB211-Q1 then waits for the next connect event to occur.
When in High Speed (HS) mode, if the ISOUSB211-Q1 detects a continuous period of no transitions lasting THSDIS, the devices samples the DD+ and DD- lines using the HS Disconnect detector. If the input differential voltage crosses VHSDSC during THSDIS, the repeater removes the HS termination from both the downstream and upstream terminals and transitions to a disconnect state. The ISOUSB211-Q1 then waits for the next connect event to occur.