Continuousand discrete-time switching audio power amplifiers are studied both with and without feedback. Pulse-width modulation (PWM) and sigma–delta modulation (SDM) amplifier configurations are simulated and their interrelationship is described using linear phase modulation (LPM) and linear frequency modulation (LFM). Distortion generation encountered when applying negative feedback to PWM is...

This paper proposes a structured methodology for the design of high-performance audio amplifiers without use global negative feedback. type amplifier is being suggested in order to minimize supposed deleterious effects on quality. The proposed uses minimum number stages with local feedback operating high voltage range harmonic distortion need As an example applying methodology, 50W power design...

A high performance digital audio amplifier system requires an asynchronous sample rate converter to synchronize the input digital data stream to the low jitter system clock used to generate the digital PWM output. By performing the sample rate conversion with highly oversampled signals the computation and memory requirements are minimized. The performance of the digital amplifier system is not ...

This paper presents a new engineering approach to audio clipping preamplifier that can be used for the tone modification and volume control of electronic devices. The approach consists of a unique design based on a summation amplifier, Silicon Controlled Rectifiers (SCR) and RC networks that enables signal gain, improved frequency response, tone modification and signal shape clipping. The propo...

An audio transformer is used in a guitar amplifier to match the impedances of the power amplifier and a loudspeaker. It is important to understand the influence of the audio transformer on the overall sound quality for realistic tube amplifier emulation. This paper proposes to simulate the audio transformer using a wave digital filter model, which is based on the gyrator-capacitor analogy. The ...

RF immunity, or RF susceptibility, is quickly becoming as important a design consideration as PSRR, THD+N, and SNR in the audio portions of cellular phones, MP3 players and notebook computers. Bluetooth is proliferating as a wireless-serialcable replacement for headsets and microphones in mobile applications. Wireless LAN (WLAN), using the IEEE 802.11b/g protocol, is practically standard in PC ...

The quality of an audio signal reproduction in the room is depending on many factors. Since the CD audio has become standard, the audio devices have to provide high quality reproduction. In comparison with video playback, where the lower resolution and frame rate is often satisfactory for the user, very high standards are expected in audio products area. High performance of the modern consumer ...

Class D amplifiers are typically very efficient, making them ideal candidates for portable applications that require long battery life and low thermal dissipation. However, electromagnetic interference (EMI) is an issue that commonly accompanies the Class D switching topology. Activeemissions limiting reduces radiated emissions and enables "filterless" operation, allowing designers to create sm...