Over-Voltage Protection on the CC Pin of USB Type-C Interface against Electrical Overstress Events

摘要

In USB type-C interface, owing to the shrinking space between the pins of connector and the required high-power delivery, the electrical overstress (EOS) events due to some pins shorting to VBUS pin during plugging or unplugging operations had been reported. In this work, an over voltage protection (OVP) design on the CC pin of USB type-C IC was proposed, where a HVNMOS as a pass transistor was used to avoid the CC pin from EOS. An EOS detection circuit is proposed to turn off the gate of the HVNMOS when EOS stressing on the CC pin, which can mitigate the hot carrier degradation (HCD) of HVNMOS. Silicon chip fabricated in a 0.15-μm BCD technology has been measured to successfully verify the proposed OVP design in device level and circuit level.