Pulse Coding Controlled Switching Converters with Notch Frequency Generation in Noise Spectrum

Abstract

This paper proposes a new technology about generating notch characteristics in noise spectrum of DC-DC switching converters for the communication devices. There are very few reports about the pulse coding controlled switching converter, though it is sometimes used in digital-to-analog converter (DAC) field, to our knowledge. We have investigated the pulse coding technology to switching converters to generate automatically the notch characteristics in the noise spectrum. The notch frequency Fn in the spectrum of the switching pulses is created by two coding pulses to control the main power switch. The clock and coding pulses are automatically generated from the input frequency Fin to create the notch frequency Fn=Fin. In addition, the notch frequency is experimentally confirmed with the prototype circuit.