USB Type-C protection switch improves safety

Alpha and Omega Semiconductor Ltd. (AOS) has released the AOZ1377DI protection switch to enhance USB Type-C efficiency and safety. The USB Type-C sourcing protection switch supports up to 7 A with up to 20-V input voltage, supporting both sink and source applications. This current-limiting protection switch is designed for applications such as smartphones, tablets, notebooks, ultra-books and PCs, as well as other Type-C portable devices.

(Source: Alpha and Omega Semiconductor Ltd.)

The AOZ1377DI provides advanced features that reduce voltage drop and power loss compared with back-to-back p-channel devices typically used, AOS said. The switch supports an input operating voltage range of 3.4 V to 23 V, with both VIN and VOUT terminals rated at a maximum of 28 V. The devices are suited for high-power applications requiring multi-port Type-C PD 3.0 current source supporting up to 100 W.

Designed to provide comprehensive protection, the AOZ1377DI offers true reverse current blocking (TRCB) protection that avoids undesired reverse current from VOUT to VIN and the current limit threshold can be set externally with a resistor. The internal current-limiting and short-circuit limit protects the source device from large load current, while the integrated back-to-back MOSFET offers the “lowest ON resistance [19 mΩ typical] and highest SOA” to safely handle high currents and a range of output capacitances on VOUT, the company said.

Another key feature is the programmable soft start to control the inrush current for highly capacitive loads and an external capacitor can adjust the slew rate, AOS said.

Other protection features include input under-voltage lock out (UVLO), input over-voltage protection (OVP) and thermal shut down protection (TSD). Devices consume only 3 µA in shutdown.

Available in two variants, when fault conditions are cleared, the AOZ1377DI-01 will auto-restart and the AOZ1377DI-02 will latch the power switch off and EN must be reset to restart the device, the company said.

The AOZ1377DI-01 and AOZ1377DI-02 are available in production quantities with a lead time of 16 weeks. The unit price in quantities of 1,000 is $1.356. The AOZ1377DI is housed in a small 10-pin DFN (3 × 3 mm) package and is UL 2367 and IEC62368-1 certified.