USB-C PD switch has source and sink
Alpha and Omega Semiconductor (AOS) has launched a combination switch for USB Type-C Power Delivery (USB-C PD) that can handle an absolute maximum voltage of 28V.
The AOZ1380 is a smart protection switch combining both current source and sink function in a thermally enhanced 3mm x 5.2mm DFN package.
The switch combines a high-performance chip with protection features and a MOSFET with a high safe operating area (SOA). This provides true reverse current blocking intended for applications where protection from exposure to high voltages is required such as notebooks, ultrabooks, Chromebooks, and docking stations, with Thunderbolt/USB-C PD ports.
In the sinking application, two discrete back to back MOSFETs along with resistors and capacitors provide soft start functionality to prevent Type C power adaptor brownout at the plugin. However, programmability and protection features such as reverse-current blocking and over-voltage and over-temperature protection are lacking in this implementation.
As a USB-C PD port must also provide power delivery of up to 15W in a notebook application, there’s also a need for a 5V current limited load switch with protection features. The AOZ1380 provides this functionality and reduces board footprint by half. The internal back to back discrete MOSFET that provides the sinking path has a low 20mΩ source to source resistance of for sink and 39mΩ for the source path.
The trench MOSFETs is built on AOS’ hot-swap platform that provides a high SOA in soft start conditions. The low resistance enables high continuous current of 7A and peak currents of up to 20A for 10ms at a 2 per cent duty cycle for load switch designs in notebook applications where high peak current capability from the adaptor are needed for CPU or GPU turbo mode events. The AOZ1380 also supports the sinking switch requirements with the fastest response time in the industry to support fast role swap events. The operating range is 3.4V to 22V for sink path and 3.4V to 5.5V for the sourcing path with a 28V absolute maximum rating for VBUS
“The thinner profile, higher power, and greater flexibility offered by USB-C and USB PD 3.0 standards have prompted many computer manufacturers to drop the barrel jack in favour of USB-C ports for charging notebook and ultrabook offerings. The unique combination of AOS’ high SOA MOSFET technology and controller ICs enables system designers to achieve a compact footprint while enhancing the reliability of the Type C port,” said Peter Cheng, Power IC Senior Marketing Director at AOS.
The AOZ1380 is immediately available in production quantities with a lead-time of 12 weeks. The unit price of 1,000 pieces is $2.25.