Constant Switching Frequency Self-Oscillating Controlled Class-D Amplifiers

Constant Switching Frequency Self-Oscillating Controlled Class-D Amplifiers

Investigation of switching frequency variations in self-oscillating class D amplifiers

Class D audio amplifiers have gained significant influence in sound reproduction due to their high efficiency. One of the most commonly used control methods in class D amplifiers is known as self-oscillation. An parameter of key interest in self-oscillating class D amplifiers is the switching frequency, which can be directly related to the performance of the amplifier. This paper will clearify ...

THD Analysis in Closed-Loop Analog PWM Class-D Amplifiers

In this paper, we investigate the parameters affecting Total Harmonic Distortion (THD) and Power Supply Rejection Ratio (PSRR) in PWM Class D Amplifiers (CDAs) on the basis of linear models with feedback. From our mathematical analysis, we show that the THD of a PWM Class D amplifier with feedback can be improved by increasing the gain of the integrator through adding another amplifier at the o...

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...

Linear-Assisted DC-DC Switching Converter with Constant Switching Frequency

This article shows the proposal of a linear–assisted converter or linear–&–switching hybrid converter with a constant switching frequency. The control loop of the system is based on the current–mode technique. The main disadvantage of a converter with current–mode control is the inherent instability of the loop when switch duty ratios are greater than 0.5. In order to make stable the proposed l...