A 0.02% THD and 80 dB PSRR filterless class D amplifier with direct lithium battery hookup in mobile application

Zheng, Hao; Zhu, Zhangming; Ma, Rui

doi:10.1088/1674-4926/38/7/074002

Cited by 3 publications

(2 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Improving these performances is especially important in battery powered portable devices. However, the full implementation of Class-D technology in portable devices required solving many problems in order to improve electroacoustic, energy, and electromagnetic compatibility (EMI) performance and filter the output signal [1][2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Filterless, Digital Class-BD Audio Amplifiers with Constant Common Mode Output Voltage

et al. 2021

View full text Add to dashboard Cite

This paper presents new and original architectures and implementations of two filterless, open-loop digital Class-BD audio amplifiers with constant common mode (CM) output voltage. The first, low-power amplifier consists of four ultrahigh-current EL7158 pin drivers, the OUT pins of which form the H bridge. The drivers are controlled from the extended LBDD PWM modulator and have appropriately set voltage levels on the VL and VH pins. The second proposed amplifier consists of two cooperating H-bridge power stages (HBS) implemented on complementary MOSFET pairs and powered by two different voltages. Both HBSs are driven by four EL7158 pin drivers having appropriately adjusted voltage levels on the VL and VH pins and controlled by an extended LBDD PWM modulator. The hybrid 9 bit DPWM modulator uses a linearized Class-BD double-sided modulation scheme with pre-compensation, enabling the most faithful emulation of natural NBDD PWM and, thus, providing attractive spectral characteristics at the DM output. Basic SPICE simulations and experimental results of the proposed digital Class-BD amplifiers were compared with the conventional digital Class-BD amplifiers. The elimination of CM signals significantly contributes to the reduction in electromagnetic interference (EMI), particularly those produced on the cables connecting the loudspeaker to the HBS terminal. Proposed Class-BD amplifiers with original and new topologies, due to their simple design and easy control (no galvanic isolation of control signals and no floating bias power supplies), which generate no CM voltage and feature excellent DM performance, similar to conventional Class-BD amplifiers, are very attractive solutions for filterless Class-BD amplifiers.

show abstract

Section: Introductionmentioning

confidence: 99%

Filterless, Digital Class-BD Audio Amplifiers with Constant Common Mode Output Voltage

et al. 2021

View full text Add to dashboard Cite

show abstract

“…e digital switching signal modulator mostly uses uniform-sampling pulse width modulation (UPWM) technology realization. e LC low-pass filter of the traditional digital class D power amplifier occupies about 75% of the volume of the entire power amplifier system and consumes about 30% of the cost, which severely hinders the portable application of digital class D power amplifiers [4].…”

Section: Introductionmentioning

confidence: 99%

Improved Error Correction Methods for Filterless Digital Class D Audio Power Amplifier Based on FCLNF

Sun

2020

Mathematical Problems in Engineering

View full text Add to dashboard Cite

Aiming at correcting the error caused by the nonlinear and power supply noise of the bridge-tied-load (BTL) power stage of the filterless digital class D power amplifier, an error correction method was proposed based on feedforward power supply noise suppression (FFPSNS) and first-order closed loop negative feedback (FCLNF) techniques. This method constructed the first-order LCLNF loop for the power stage and further reduced the impact of the power supply noise on the power amplifier output by using FFPSNS technology to introduce the power supply noise into the feedback loop at the same time. The 0.35 μm CMOS process is used for analysis and comparison in Cadence. Cadence simulation results indicate that PSRR at the power supply noise frequency of 200 Hz is improved with 36.02 dB. The power supply induced intermodulation distortion (PS-IMD) components are decreased by approximately 15.57 dB and the signal-to-noise ratio (SNR) of the power amplifier is increased by 17 dB. The total harmonic distortion + noise (THD + N) of the power amplifier is reduced to 0.02% by FCLNF + FFPSNS.

show abstract

Three-frequency pseudo-random varying spread spectrum method for filterless digital class-D audio amplifiers

et al. 2020

View full text Add to dashboard Cite

A 0.02% THD and 80 dB PSRR filterless class D amplifier with direct lithium battery hookup in mobile application

Cited by 3 publications

References 8 publications

Filterless, Digital Class-BD Audio Amplifiers with Constant Common Mode Output Voltage

Filterless, Digital Class-BD Audio Amplifiers with Constant Common Mode Output Voltage

Improved Error Correction Methods for Filterless Digital Class D Audio Power Amplifier Based on FCLNF

Three-frequency pseudo-random varying spread spectrum method for filterless digital class-D audio amplifiers

Contact Info

Product

Resources

About