UNISONIC TECHNOLOGIES CO., LTD
USB HIGH-SIDE POWER SWITCH
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.
* Open-Drain Fault Flag
* Low on-Resistance MOSFET: Typical 110mΩ(at 5.0V)
* Operating Voltage Varying From 3.0V to 5.5V
* Output can be Forced Higher than Input when Operating in Off State.
* Slow Turn-On (Soft-Start) and Fast Turn-Off
* On-State Supply Current: 100 µA (TYP)
* Standby Supply Current: 1µA (TYP)
* Current Limit: 1.4A (TYP)
* Thermal Shutdown Protection Circuit
* UVLO (Under-Voltage Lockout): 2.4V (TYP)
* Logic Level Enable Pin, Available with Active-High/Low Version
Copyright © 2010 Unisonic Technologies Co., Ltd
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