Switching Regulator using LM1758 A

LM1578A Switching Voltage Regulator

The National Semiconductor LM 1578 A is a switching regulator which can easily be set up for such dc-to-dc voltage .conversion circuits as the buck, boost, and inverting configurations. The LM 1578 A features a unique comparator input stage which not only has separate pins for both the inverting and non-inverting inputs, but also provides an internal 1.0 V reference to each input, thereby simplifying circuit

design and PC board layout. The output can switch upto 750 m A and has output pins for its collector and emitter to promote design flexibility. An external current limit terminal may be referenced to either the ground or the V_in terminal, depending upon the application. In addition, the LM 1578 A has an on board oscillator, which sets the switching frequency with a single external capacitor from < 1 Hz to 100 kHz (typical). It operates from supply voltages of 2 V to 40 V. It is provided with current limit and thermal shutdown. Duty cycle up to 90 %. Functional diagram is given in figure.