A novel delta-sigma modulated DC-DC power converter operating under DC ripple voltage

Abstract

A delta-sigma modulator is effectively utilized as a PWM pattern generator for high-frequency switching mode inverters. However, in the case that it is applied for voltage source chopper type DC-DC converters, it is noted that the significant features cannot be achieved and implemented. The authors propose a novel delta-sigma modulation circuit which alters a quantized feedback signal to a continuous signal of a DC-DC converter output. If the ripple voltage of the input side DC source exists in practice, a fluctuation in the feedback signal is produced. As a result, the proposed delta-sigma modulator has the inherent nature of spread spectrum. Furthermore, the delta-sigma modulated converter circuit can be considered as an error amplifier, and automatic amplitude control characteristics will be implemented in this converter.