Systematic design of output filters for audio class-D amplifiers via Simplified Real Frequency Technique

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...

Measuring Class-D Amplifiers for Audio Speaker Overstress Testing

Determining if audio speaker limitations are violated can be challenging when using Class-D amplifiers. To obtain valid results, it is necessary to carefully analyze and interpret the switching behavior of the output signals . Filter-free Class-D amplifiers further complicate measurement because they do not require an output filter and the speaker can be connected directly to the amplifier outp...

HIGH-VOLTAGE CLASS-D POWER AMPLIFIERS: DESIGN AND OPTIMIZATION Haifeng Ma HIGH-VOLTAGE CLASS-D POWER AMPLIFIERS: DESIGN AND OPTIMIZATION

i ABSTRACT Nowadays transducers are ubiquitous as interfaces between the increasingly digital world and the real physical world. The same holds for the power amplifiers driving them. This thesis focuses on the design and optimization of high-voltage class-D amplifiers, which are used for driving capacitive piezoelectric actuator loads in active vibration/noise control applications. The main obj...

Constant Switching Frequency Self-Oscillating Controlled Class-D Amplifiers

Class D audio amplifier with Ferroxcube gapped toroid output filter