USB5906 datasheet(34/64 Pages) MICROCHIP

34 / 64 page

USB5906

DS00002242E-page 35



2016-2021 Microchip Technology Inc.

When the port is enabled, the

PRT_CTLx pin input is constantly sampled. Overcurrent events can be detected in one

of two ways:

• Single, continuous low pulse (consecutive low samples over tocs_single), as shown in Figure 8-6.

• Two short low pulses within a rolling window (two groupings of 1 or more low samples over tocs_double), as shown

in Figure 8-7.

To maximize compatibility with various port power control topologies, the parameters tocs_single and tocs_double are con-

figurable via the Overcurrent Minimum Pulse Width Register and Overcurrent Inactive Timer Register.

The pin also has a turn-on “lockout” feature where the state of the pin is ignored for a configured amount of time imme-

diately after port power is turned on. This prevents slow ramp times due to parasitic resistance/capacitance attached to

the pin from triggering false overcurrent detections. This parameter is configurable via the Overcurrent Lockout Timer

FIGURE 8-5:

PORT POWER CONTROL WITH USB POWER SWITCH

FIGURE 8-6:

SINGLE LOW PULSE OVERCURRENT DETECTION

FIGURE 8-7:

DOUBLE LOW PULSE OVERCURRENT DETECTION

USB Power

Switch

50k

PRTPWR

OCS

Pull‐Up Enable

USB

Device

FILTER

PRT_CTLx

IS VIL

tocs_single

PRT_CTLx

IS VIL

tocs_double

USB5906 Datasheet(PDF) 34 Page - Microchip Technology