EMI Reduction in Class-D Amplifiers by Actively Reducing PWM Ripple

Lokin, Christiaan E.; Zee, Ronan van der; Schinkel, D.; Nauta, Bram

doi:10.1109/tcsi.2019.2952543

Cited by 8 publications

(4 citation statements)

References 17 publications

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“…Converting signals to PWM is a task commonly reproduced in recent studies [21][22][23], either to reduce electromagnetic interference [21] or to amplify signals [22][23]. In this work, the function of this conversion is to make the signal amplified by the coil, 𝑉 𝑜 , as understandable as possible, reducing the noise at the input 𝑉 𝑖 .…”

Section: Audio Convertermentioning

confidence: 99%

Projeto de circuito de bobina de Tesla com filtro de áudio FIR / Tesla coil circuit Project with FIR audio filter

Moura¹

2022

BASR

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In this work, the small-signal model and the construction of a high-power transistor circuit similar to Tesla coils, called slayer exciter, are presented. In addition to the hardware design, this article also presents the design of an algorithm that uses an FIR (finite impulse response) filter to convert audio signals into PWM pulses, pulse width modulation, at the input of the circuit, which generate arcs. at the frequency of the input pulse, thus producing music.

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Section: Audio Convertermentioning

confidence: 99%

Projeto de circuito de bobina de Tesla com filtro de áudio FIR / Tesla coil circuit Project with FIR audio filter

Moura¹

2022

BASR

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“…4. To reduce the power consumption of this output stage, a PP modulation scheme [10], [11], [12], [13] is employed. In such a scheme, also known as ternary modulation, BD modulation with low CM, and half-side switching, only half of the H-bridge switches, while the other half remains grounded, as illustrated by the timing waveforms in Fig.…”

Section: B Pp Modulation and Load Current Sensingmentioning

confidence: 99%

A −91 dB THD+N, Class-D Piezoelectric Speaker Driver Using Dual Voltage/Current Feedback for Resistor-Less LC Resonance Damping

Karmakar

Berkhout²,

Makinwa

et al. 2022

IEEE J. Solid-State Circuits

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This article presents a Class-D audio amplifier for capacitive piezoelectric speaker loads. Employing a dual voltage feedback (VFB)/current feedback (CFB) topology, the amplifier is capable of damping LC resonance without using an external damping resistor, therefore reducing system power consumption, cost, and size. Additional power savings are achieved by using a push-pull (PP)-modulated output stage. To mitigate linearity degradation due to the mismatch of the feedback resistors, they are dynamically matched by employing choppers. The prototype, taped out in a BCD 180-nm process, can drive up to 4 µF load with a peak current of 4.4 A while achieving an idle power consumption of 122 mW and a peak THD+N of −91 dB.

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“…The spread-spectrum technique, a highly effective method for reducing the electromagnetic interferences produced by switching converters, has been gaining traction in recent years. This method is utilized in a wide array of switching devices, including on-chip power supplies [8], audio amplifiers [9] and [10], and power converters [11]. Although frequently employed in commercial products, it has been noted [12] that the parameters of the spread-spectrum technique often remain unoptimized for their specific applications.…”

Section: Introductionmentioning

confidence: 99%

Clock Frequency Optimization of a Compensated Spread-Spectrum Controller in Buck Converters

Kundrata,

Baric

2024

IEEE Access

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This research investigates the spread-spectrum technique's impact on buck converters, with a focus on electromagnetic emissions and output voltage ripple. The ripple, attributed to constant delay time in the PWM generator, induces changes in the duty cycle as the switching frequency varies due to the spread-spectrum technique. To alleviate this, a time delay compensation mechanism recalculated at each switching frequency change is proposed. To address duty cycle inaccuracies from integer calculations in a digital core, a remainder accumulator in time delay calculation is introduced. A numerical model parametrized by the controller's clock frequency and spread-spectrum resolution examines duty cycle error, ripple, and EMI peak reduction. Findings indicate that the proposed compensator and accumulator reduce duty cycle error while maintaining comparable ripple and achieving similar EMI peak reduction. EMI peak reduction plateaus at higher clock frequencies, suggesting an optimal clock frequency. Experimental results from an FPGA prototype corroborate the model and simulations, showing substantial duty cycle error reduction, comparable ripple, and maximized EMI peak reduction. The study thus illustrates the spreadspectrum technique's potential in buck converters, providing an optimal configuration for EMI reduction and minimizing duty cycle error and ripple.INDEX TERMS DC-DC converter, digital design, duty cycle ripple, EMI, spread-spectrum

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EMI Reduction in Class-D Amplifiers by Actively Reducing PWM Ripple

Cited by 8 publications

References 17 publications

Projeto de circuito de bobina de Tesla com filtro de áudio FIR / Tesla coil circuit Project with FIR audio filter

Projeto de circuito de bobina de Tesla com filtro de áudio FIR / Tesla coil circuit Project with FIR audio filter

A −91 dB THD+N, Class-D Piezoelectric Speaker Driver Using Dual Voltage/Current Feedback for Resistor-Less LC Resonance Damping

Clock Frequency Optimization of a Compensated Spread-Spectrum Controller in Buck Converters

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