IC Voltage Regulators-with Circuit Diagram - Design & Theory The functional block diagram of the IC as a switching regulator is shown below. From the functional diagram we can see that the IC has a comparator circuit with an inverting and on-inverting input along with a 1 volt internal reference to each input, which clearly simplifies the circuit design and PCB layout. Different Types of Voltage Regulator and Working Principle A switching regulator with Pulse Width Modulation, constant frequency, varying duty cycle, is efficient and easy to filter out noise. In a switching regulator, continuous mode current through an inductor never drops to zero. It allows highest output power. It gives better performance.