PWM Power Audio Amplifier With Voltage/Current Mixed Feedback for High-Efficiency Speakers

Adduci, P.; Botti, E.; Dallago, E.; Venchi, G.

doi:10.1109/tie.2007.892610

Cited by 37 publications

(18 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ferrite losses are the dominating ones. audio amplifiers driving electrodynamic transducers are wellknown [6], [4], [20], [5], [21]. The big advantage of such control schemes is the fact, that stability is maintained, even when no resistive load is connected to the amplifier.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

A high-voltage class D audio amplifier for dielectric elastomer transducers

Nielsen

Knott

Andersen

2014

2014 IEEE Applied Power Electronics Conference and Exposition - APEC 2014

View full text Add to dashboard Cite

Abstract-Dielectric Elastomer (DE) transducers have emerged as a very interesting alternative to the traditional electrodynamic transducer. Lightweight, small size and high maneuverability are some of the key features of the DE transducer. An amplifier for the DE transducer suitable for audio applications is proposed and analyzed. The amplifier addresses the issue of a high impedance load, ensuring a linear response over the midrange region of the audio bandwidth (100 Hz -3.5 kHz). THD+N below 0.1% are reported for the ± 300 V prototype amplifier producing a maximum of 125 Var at a peak efficiency of 95 %. [7]. While these audio systems are dominating the market of sound reproduction, they suffer from the poor efficiency imposed by the electrodynamic transducer, and the weight of the electromagnet. As a consequence the audio community is constantly searching for new audio transducers. An alternative to the electrodynamic transducer is the electrostatic transducer. Electrostatic transducers are known from their usage in electrostatic loudspeakers, however Dielectric Elastomers (DE) can also be used to form an electrostatic transducer [8], [9], [10]. Such capacitive transducers present a high impedance, frequency depended nonlinear load to the amplifier. A DE transducer is shown in figure 1. The DE transducer is constructed by printing compliant electrodes on a thin piece of silicone. Commercial electrostatic loudspeakers are driven from tube, linear or audio-transformer based amplifier solutions. Consequently these systems suffer from being bulky, fragile and inefficient. In order to establish the full potential of the DE transducer, a new generation of audio amplifiers must be developed. These amplifiers should have a high power density, low power loss and be robust. Accordingly it is proposed to use a switch-mode audio amplifier or class D amplifier for driving the DE transducer INTRODUCTION

show abstract

Section: Discussionmentioning

confidence: 99%

“…For the purpose of designing the self-oscilation control loop, the controller transfer function must be defined (21) K can be derived using equation (19) and (21) …”

Section: A Self-oscillationmentioning

confidence: 99%

A high-voltage class D audio amplifier for dielectric elastomer transducers

Nielsen

Knott

Andersen

2014

2014 IEEE Applied Power Electronics Conference and Exposition - APEC 2014

View full text Add to dashboard Cite

show abstract

“…Alternative approaches are using a mixed voltage/current feedback to reduce distortion [11] and using a linear amplifier and a switching amplifier in a masterslave configuration [12]. The mixed voltage/current feedback configuration is shown in Recently, Pulse Density Modulated (PDM) class-D amplifiers based on analog  modulators with high-pass noise-shaping characteristics have been introduced as an alternative scheme for controlling the switching power stage [13]- [16].…”

Section: State Of Artsmentioning

confidence: 99%

A 280 mW, 0.07% THD+N class-D audio amplifier using a frequency-domain quantizer

Lee

Copani

Mayhugh

et al. 2011

Analog Integr Circ Sig Process

View full text Add to dashboard Cite

show abstract

“…For high-power, wideband applications such as UMTS and LTE, those PAs do still suffer from nonlinear distortion, so we still need some kind of linearization. In the second trick, for a given PA operating near saturation, the linearity can be improved by signal processing techniques, PA linearization [11], using techniques such as a) feedback distortion compensation [12], [13], [14], [15], [16], using closed-loop regulators to reduce the nonlinear distortion, b) feedforward distortion compensation [17], [18], [19], [20], [21], which utilizes an additional error amplifier in the forward loop to compensate for the nonlinear distortion introduced by the main PA, and c) predistortion linearization [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], which uses a stand-alone module to pre-distort the input signal to the PA, improving the linearity at PA output. Due to its high flexibility and excellent linearization performance, digital predistortion (DPD) has become one of the most preferred choice for linearizing RF PAs, and tends to be an fundamental component in current and next-generation wireless communication systems.…”

Section: Introduction or Backgroundmentioning

confidence: 99%