US1528

UNISONIC TECHNOLOGIES CO., LTD US1528 Preliminary USB HIGH-SIDE POWER SWITCH ADVANCE INFORMATION „ DESCRIPTION The UTC US1528 is an integrated high-side power switch. It is designed particularly for self-powered and bus-powered USB (Universal serial bus) applications. The UTC US1528 meets the requirements of the USB. The low on-resistance of the switch meets USB voltage drop requirements. When the output load becomes higher than the current-limit threshold, the UTC US1528 switches into constant- current mode and limits the output current at 1.4A (TYP). An open-drain flag, playing a role as the MOSFET output, is included to indicate error conditions to the local USB controller. A thermal shutdown circuit protects this device from catastrophic switch failure, which is caused by increasing power dissipation when continuous heavy loads or short circuit occurs. In addition, soft start is used to avoid the momentary voltage drop generated on the upstream port that may occur when the switch is enabled in bus-powered applications. A UVLO (under-voltage lockout) circuit is used to keep the device off unless there is a valid input voltage present, and an enable input that is compatible with both 3.3V and 5V logic. The UTC US1528 can be used for high-side power protection switch, USB power management, USB host and self-powered hubs, hot plug-in power supplies and battery-charger circuits. „ FEATURES * Open-Drain Fault Flag * Low on-Resistance MOSFET: Typical 110mΩ(at 5.0V) * Operat...