An 80% peak efficiency, 410mW, single supply rail powered Class-I linear audio amplifier

Peng, Zhenfei; Yang, Shenghong; Ye, Feng; Hong, Zhiliang; Liu, Bill

doi:10.1109/cicc.2011.6055395

Cited by 7 publications

(37 citation statements)

References 3 publications

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“…The linearity performance of the amplifier can be quantized by the THD+N ratio. supply class H amplifier [22]. It can be observed from the figure that for the benchmark design, the THD+N ratio incurs a sharp degradation from 0.01% to 0.05% when the class H supply-tracking mode is activated.…”

Section: Measurement Resultsmentioning

confidence: 98%

“…In view of the above analysis, it is highly desired to have a power amplifier that combines the advantages of a class AB and a class D amplifier. Reference [22] proposed a supply-tracking audio amplifier where a dc-dc converter is modulated to generate a variable supply voltage that keeps the power transistor headroom constant. The authors named their proposed amplifier as 'class I', however, the concept of their work is is similar to the concept of a class H amplifier.…”

Section: Background and Motivationmentioning

confidence: 99%

“…In [26], the class H is referred as a special category of class G amplifier in which the higher supply voltage is realized by a bootstrapped capacitor and only temporary power from this higher supply voltage is available. In [22], an adaptive supply power amplifier which is able to continuously adjust the supply output is proposed but is referred to as class I amplifier. To the author's best knowledge, there is yet a naming convention for such architecture.…”

Section: Supply Railsmentioning

confidence: 99%

“…The second type of disturbance is unique for single-rail adaptive supply power amplifiers. In methods [22,36] the output CM level is switched constantly to enable the amplifier's operation with single-rail supply. These abrupt changes on output CM level will lead to high frequency spikes at the output nodes and bring in more distortions.…”

Section: Enhancing Linearity Of the Fully Differential Amplifiermentioning

confidence: 99%

“…As shown in To tackle this problem, various approaches had been implemented. One straightforward solution is to delay the audio input that is fed into the linear amplifier, therefore an additional delay time is added to the amplifier module [22]. The drawbacks of this solution is that it is still very hard to match this newly-added latency with the one of the power supply module, if it is over compensated similar issue will occur when the system is switching back from class H to class AB mode.…”

Section: Latency Between the Coarse And Fine Signal Pathsmentioning

confidence: 99%

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Analysis and design of an adaptive-supply class H audio power amplifier for mobile devices

Zhang¹

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which operates with only single-rail supply. The supply to the output stage is designed to be adaptive to the instant input signal level so that the voltage drop across the power transistor is kept constant. Therefore, compared with other linear amplifier architectures (class B/AB/G), the proposed design features much better overall power efficiency. An existing issue with the above-mentioned adaptive-supply amplifiers is the additional distortions that occur during mode switching. For class G topology when the switching threshold is reached, the supply voltage sees step changes during the low to high transitions. These abrupt changes tend to add distortions to the outputs of the amplifier. Therefore, for conventional adaptive-supply amplifiers, there is a sudden burst in the Total Harmonic Distortion (THD) when the high supply starts operating. In this research, we proposed a common-mode modulation (CMM) scheme to resolve this problem. Instead of changing the system configuration upon the triggering of mode switching, the amplitude information of the input signal is extracted and embedded into the common-mode (CM) voltage of the vi

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Section: Measurement Resultsmentioning

confidence: 98%

Section: Background and Motivationmentioning

confidence: 99%

Section: Supply Railsmentioning

confidence: 99%

Section: Enhancing Linearity Of the Fully Differential Amplifiermentioning

confidence: 99%

Section: Latency Between the Coarse And Fine Signal Pathsmentioning

confidence: 99%

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