IC voltage regulators
Four most commonly used switching converter types: Buck: used the reduce a DC voltage to a lower DC voltage. Boost: provides an output voltage that is higher than the input. Buck-Boost (invert): an output voltage is generated opposite in polarity to the input. Flyback: an output voltage that is less than or greater than the input can be generated, as well as multiple outputs. Converters: Push-Pull: A two-transistor converter that is especially efficient at low input voltages. Half-Bridge: A two-transistor converter used in many off-line applications. Full-Bridge: A four-transistor converter (usually used in off-line designs) that can generate the highest output power of all the types listed. Application information will be provided along with circuit examples that illustrate some applications of Buck, Boost, and Flyback regulators. Switching Fundamentals The law of inductance If a voltage is forced across an inductor, a current will flow through that inductor (and this current will vary with time). The current flowing in an inductor will be time-varying even if the forcing voltage is constant. It is equally correct to say that if a time-varying current is forced to flow in an inductor, a voltage across the inductor will result. The fundamental law that defines the relationship between the voltage and current in an inductor is given by the equation: v = L (di/dt)