US1528_15 Datasheet, PDF (6/8 Pages) Unisonic Technologies – USB HIGH-SIDE POWER SWITCH ADVANCE INFORMATION

US1528
Preliminary
CMOS IC
„ APPLICATIONS INFORMATION
Supply Filtering
In order to control supply transients, a bypass capacitor is located nearly between IN to GND. 0.1µF ~ 1µF is
suitable (See Figure 1). Without a bypass capacitor, an output short may cause sufficient ringing on the input (from
supply lead inductance) to damage internal control circuitry.
Input transients must not exceed the absolute maximum supply voltage (V_{IN Max} = 6V) even for a short duration.
EN/EN , The Active-High/Low Enable Input
For a clearly defined input, the EN/EN pin, with 0.2V hysteresis, must be driven logic high or logic low. Floating
the input may cause unpredictable operation. EN/EN should not be allowed to go negative with respect to GND.
Soft Start
The UTC US1528 is high impedance when off and slowly becomes a low impedance as it turns on. This
reduces inrush current and related voltage drop that results from charging a capacitive load, satisfying the USB
voltage drop requirements, for bus-powered applications as shown in Figure 2.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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QW-R502-457.b