Circuit Power Supply

The purpose of this application note is to demonstrate the many advantages of using the Supertex LND150N3 in the start-up circuit for switchmode power supplies. Commonly used low voltage bipolar, CMOS and BiCMOS switchmode power supply PWM ICs usually operate from supply voltages of up to 18V.

Read PDF : http://www.supertex.com/pdf/app_notes/AN-D25.pdf

Today’s electronic circuits require a number of different voltage potentials. Powering silicon devices like microcontrollers or digital logic require a different voltage than bias supplies or powering strings of LEDs. A system can very easily contain a combination of circuits that require different voltages. With only a single input voltage delivered to the system, a power regulator is needed to produce the necessary voltages.

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http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en022891

This application note describes a complete flyback switched mode power supply that uses a Fairchild Power Switch. The MOSFET and its control IC are built into one package. The MOSFET is in fact a SenseFET. Various protection features are also included. Fairchild Power Switch can enhance the reliability and productivity of the system when compared to other designs.
Read PDF File : http://www.fairchildsemi.com/an/AN/AN-4116.pdf