LT3574 switching power supply

The LT3574 IC is a monolithic switching regulator designed for the isolated flyback topology.  LT3574 don’t require a winding or opto-isolator for regulation. The part senses the isolated output voltage directly from the

primary side flyback waveform. A 0.65A, 60V NPN power switch is integrated in the package along with all control logic .

The LT3574 switching regulator operates over a wide input supply voltages from 3V to 40V and can deliver output power up to 3W without external power switch.

To set the output voltage is need two external resistors and the transformer turns ratio.

If you consult the manufacturer datasheet you will see that the LT3574 can be configured in many types . In this schematic diagram the switching regulator circuit will provide a dual 12 volts output (+- 12 volts ) at 40 mA current .

The LT3574 switching regulator circuit from this schematic diagram need to be powered using a 5 volts power supply .