High-efficiency dynamic supply CMOS audio power amplifier for low-power applications

Gubelmann, J.; Fabbro, Paulo Augusto Dal; Pastre, Marc; Kayal, Maher

doi:10.1016/j.mejo.2009.03.003

Cited by 7 publications

(4 citation statements)

References 9 publications

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“…Other digital blocks are modelled using Verilog-A instances with appropriate estimations of delay, speed, and power to reflect actual circuits. The speaker load is modelled as a 8 Ω resistor [5].…”

Section: Simulation Resultsmentioning

confidence: 99%

An envelope tracking H-bridged audio amplifier with improved efficiency and thd less than 0.1%

Liu

Allasasmeh

Gregori

et al. 2012

2012 25th IEEE Canadian Conference on Electrical and Computer Engineering (CCECE)

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In this paper, we present a class-H audio amplifier with an Hbridged output stage. System efficiency is improved by producing a voltage envelope that tracks the input audio signal. The tracking envelope is realized by regulating a buck converter internally using voltage and current hysteresis control schemes. The H-bridged class-B output stage is designed to maximize the output swing across the speaker load with little crossover distortion. The proposed design is capable of providing a peak output RMS power of 0.49 W to an 8 Ω speaker load. The entire system is designed and simulated in a 0.18-μm CMOS technology. In simulation, the proposed audio amplifier shows improved power efficiencies and good output linearities with THD less than 0.1% under different input signals

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Section: Simulation Resultsmentioning

confidence: 99%

An envelope tracking H-bridged audio amplifier with improved efficiency and thd less than 0.1%

Liu

Allasasmeh

Gregori

et al. 2012

2012 25th IEEE Canadian Conference on Electrical and Computer Engineering (CCECE)

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show abstract

“…In their most common form, for small signal amplitudes a minimum, fixed supply level is set; when the signal exceeds a threshold value, the supply rail dynamically tracks it with an added offset to keep the output devices in the appropriate operational region. When both positive and negative supply rails are available, they both stay fixed at low absolute voltages for small output level; and one of them tracks the output with an offset, when the output level exceeds certain thresholds [18], [19]. The same approach can be implemented in a fully-differential bridge configuration with a single supply rail [20]- [22], where a bootstrapping amplifier topology has been proposed to further improve efficiency and linearity [23].…”

Section: Introductionmentioning

confidence: 99%

Class–CTA: Concept and Theoretical Analysis of a High Linearity and Efficiency Power Stage Architecture

Baxevanakis,

Nikitas,

Sotiriadis

2023

IEEE Open J. Circuits Syst.

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This work presents a power stage architecture that combines high-linearity with highefficiency. The power stage is configured as a push-pull Class-A topology with two buck-converters providing its supply rails. The buck-converters continuously track the stage's output with a small constant margin, creating a minimum, constant voltage drop on the output devices; thus, the stage's efficiency is increased and its linearity is improved. Theoretical analysis of the topology and its feedback control are presented, while a design example is implemented and simulated in Cadence Spectre as proof-of-concept.

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“…Therefore, if the supply voltage is as close as possible to the signal amplitude, then the efficiency of the linear amplifier, given in (1), is maximized. By carefully choosing the number and voltages of the power supplies, the losses due to conduction can be further reduced [10]- [16]. In [11]- [13], the authors suggest an optimization for amplifiers with two or three power supplies, whereas in [14]- [16] they concentrate more on the optimization and implementation of the electrical parameters in order to reduce the consumption and improve the linearity (one of the components of audio quality).…”

Section: Introductionmentioning

confidence: 99%

Dynamic voltage scaling for series hybrid amplifiers

Russo

Yengui

Pillonnet

et al. 2013

Microelectronics Journal

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We present an optimization of the voltage scaling algorithm in low power audio class G amplifier for headphones application to allow longer playback time. The optimization approach minimizes the voltage difference between the internal audio amplifier power supply and its output signal over a large range of operating conditions. The modeling is based on a behavioral model enabling accurate and rapid evaluation of efficiency and audio quality with realistic input stimuli. The model validated in practice is used to optimize the voltage scaling using only few power supply levels. Thanks to a global search algorithm followed by a local one, the optimization gives the better parameters for voltage scaling algorithm while keeping a good audio quality. The proposed configuration increases the efficiency up to 48% at nominal operation.

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High-efficiency dynamic supply CMOS audio power amplifier for low-power applications

Cited by 7 publications

References 9 publications

An envelope tracking H-bridged audio amplifier with improved efficiency and thd less than 0.1%

An envelope tracking H-bridged audio amplifier with improved efficiency and thd less than 0.1%

Class–CTA: Concept and Theoretical Analysis of a High Linearity and Efficiency Power Stage Architecture

Dynamic voltage scaling for series hybrid amplifiers

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