Power switches provide protection for USB ports and hot-swap applications

By Heather Hamilton, contributing writer

Diodes Inc. recently launched the AP22815 and AP22615, a pair of 3-A single-channel, high-side power switches for USB ports and hot-swap applications such as USB peripherals or external storage devices. Designed to offer port protection for sensitive electronic equipment, the switches provide auto-recovery, which includes overvoltage, overcurrent, short-circuit, and overtemperature. They also feature a discharge function for external storage capacitors and controlled rise-time and undervoltage lock-out.

The switches are based on an N-channel MOSFET and Diodes’ copper-pillar packaging technology to deliver very low on-resistance. The new pair of switches offers a wide input voltage range of 3.0 V to 5.0 V and, for the AP22615, an adjustable limited load current of up to 4.0 A.

Both integrated load switches have a low RDS(ON) of 40 mΩ and high ESD protection (2-kV human body model, 200-V machine model). Applications include notebooks, netbooks, tablets, set-top boxes, USB chargers, and other consumer electronics devices.

Both power switches are compliant with the USB power delivery and fast-role swap specifications. “This ensures that the internal power transistor will detect and react to the presence or absence of a power rail within 150 µs, thereby supporting the hot-swapping of USB power sinks and sources without resulting in any disruption to the consumer experience,” said Diodes.

The switches feature an enable (specified either as active-high or active-low) and a dedicated flag output that identifies a fault condition. For devices with a high load capacitance, a 7-ms deglitch period is also built in to prevent false triggers.

The AP22815 with fixed current limiting is available in the TSOT25 package at a price of $0.40 each in quantities of 1,000. The AP22615 with adjustable current limiting is available in a TSOT26 package at $0.45 each in quantities of 1,000.