Design of a delta-sigma modulated switching power supply

An alternative control solution for a switching power supply using a delta-sigma (ΔΣ) modulator in place of a PWM controller is presented. The ΔΣ modulator controller does not exhibit the spikes in the noise spectrum characteristic of the PWM controller. A multi-bit ΔΣ modulator controller reduces the output noise floor below the conventional PWM controller noise floor. While the PWM is shown to have better power transfer efficiency, possible alternatives are suggested to increase the ΔΣ modulator controller efficiency