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US2076 Datasheet(PDF) 3 Page - UNISEM |
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US2076 Datasheet(HTML) 3 Page - UNISEM |
3 / 4 page ![]() US2076 4-3 Rev. 1.3 4/26/98 PIN DESCRIPTIONS PIN DESCRIPTIONS PIN # PIN SYMBOL PIN DESCRIPTION 3 Vfb1 A resistor divider from this pin to the output of the switching regulator and ground sets the Core supply voltage. 6 Vout The output of the linear regulator. A minimum of a 100uF low ESR capacitor must be connected from this pin to ground to insure stability. 7 Vin The input pin of the linear regulator. Typically a large storage capacitor is connected from this pin to ground to insure that the input voltage does not sag below the minimum drop out voltage during the load transient response. This pin must always be higher than Vout plus the maximum dropout voltage in order for the device to regulate properly. 4 Gnd This pin is connected to the IC substrate and must be connected to the lowest potential in the system. It is also connected to the Tab of the package. 1 Drv The PWM output of the switching controller. This pin is a totem pole drive that is connected to the gate of the power MOSFET. A resistor may be placed in series from this pin to the gate in order to reduce switching noise. 5 Vfb2 A resistor divider from this pin to the output of the linear regulator and ground sets the I/O supply voltage. 2 V12 This pin is connected to the 12V supply voltage. A high frequency cap must be connected from this pin to the GND pin of the IC. BLOCK DIAGRAM BLOCK DIAGRAM Figure 1 - Simplified block diagram of the US2076 Note 1 : Low duty cycle pulse testing with Kelvin con- nections are required in order to maintain accurate data. Note 2 : Drop-out voltage is defined as the minimum differential voltage between Vin and Vout required to main- tain regulation at Vout. It is measured when the output voltage drops 1% below its nominal value. Note 3 : Minimum load current is defined as the mini- mum current required at the output in order for the out- put voltage to maintain regulation. Typically the resistor dividers are selected such that it automatically main- tains this current. Vref UVLO 1.25V PWM Control V12 Vout Drv Gnd Vfb 1 Vin 4 1 2 3 6 7 2076blk1-1.1 Vfb2 5 5V Reg |