Phase-shift self-oscillating class-D audio amplifier with multiple-pole feedback filter

Self-Oscillating Class-D Audio Amplifier With A Phase-Shifting Filter in Feedback Loop

A self-oscillating class-D audio amplifier adopting the phase-shifting looap filter in the feedback filter is proposed. To validate the design, a mathematical model is proposed. It is alleged in a very simple form which describes the switching frequency variation as the function of the modulation depth to be applied to any general structure: phase shifting, time delay of the loop, and the hyste...

Class D audio amplifier with Ferroxcube gapped toroid output filter

Class-D Audio Amplifiers with Negative Feedback

There are many different designs for audio amplifiers. Class-D, or switching, amplifiers generate their output signal in the form of a high-frequency square wave of variable duty cycle (ratio of on time to off time). The square-wave nature of the output allows a particularly efficient output stage, with minimal losses. The output is ultimately filtered to remove components of the spectrum above...

A Second-Order Class-D Audio Amplifier

Class-D audio amplifiers are particularly efficient, and this efficiency has led to their ubiquity in a wide range of modern electronic appliances. Their output takes the form of a high-frequency square wave whose duty cycle (ratio of on-time to off-time) is modulated at low frequency according to the audio signal. A mathematical model is developed here for a second-order class-D amplifier desi...

Self-Oscillating CMOS Class D Amplifier Optimized for Low Output Power

Advisor: l\[ichacl Hoffman The continual push for smaller size and decreased power consumption has prompted the adoption of class D amplification for speaker and headphone drivers in portable media devices. \Vith proper design, the power efficiency of this amplifier type can exceed any other topology over the whole output range, even at low output levels. Simple amplifier topologies arc not the...