Randomized Carrier PWM With Exponential Frequency Mapping

Pulsewidth modulation (PWM) and sigma-delta modulation (SDM) have been used in several high linearity, high accuracy power delivery applications such as dc-dc power converters, audio, and radio frequency power amplifiers and data converters. While PWM can generate high linearity signals with high efficiency, it suffers from discrete tonal output spectrums. SDM, on the other hand, can generate high linearity output spectrums with shaped quantization noise spectrums and lower efficiencies due to oversampling requirements. In this paper we present a particular class of carrier frequency modulated PWM (CFMPWM), which spreads the tonal content of regular PWM uniformly in frequency and reduces the baseband noise with respect to SDM by up to 15 dB. The new modulation scheme preserves the high efficiency properties of PWM. An approximate method to estimate the spectrum of CFMPWM signals with both deterministic and random modulation is also presented. Simulation results and experimental data are reported to analyze the spectral spreading properties of the proposed CFMPWM scheme

[1]  R. Kok,et al.  On designing sigma-delta converter systems for class-D power amplifiers , 1999, 1999 IEEE Africon. 5th Africon Conference in Africa (Cat. No.99CH36342).

[2]  R. J. Webster,et al.  Spectral line profiles generated by deterministic frequency modulation , 1991, IEEE Trans. Signal Process..

[3]  T. Tanaka,et al.  Random-switching control in DC-to-DC converters: an implementation using M-sequence , 1997, Proceedings of Power and Energy Systems in Converging Markets.

[4]  George C. Verghese,et al.  Analysis and synthesis of randomized modulation schemes for power converters , 1993 .

[5]  Frede Blaabjerg,et al.  Random modulation techniques with fixed switching frequency for three-phase power converters , 2000 .

[6]  Henry Shu-Hung Chung,et al.  A comparative investigation on the use of random modulation schemes for DC/DC converters , 2000, IEEE Trans. Ind. Electron..

[7]  W. McFarland,et al.  An IC for linearizing RF power amplifiers using envelope elimination and restoration , 1998, 1998 IEEE International Solid-State Circuits Conference. Digest of Technical Papers, ISSCC. First Edition (Cat. No.98CH36156).

[8]  T. Habetler,et al.  Acoustic noise reduction in sinusoidal PWM drives using a randomly modulated carrier , 1989 .

[9]  K. Borisov,et al.  A novel random PWM technique with low computational overhead and constant sampling frequency for high-volume, low-cost applications , 2005, IEEE Transactions on Power Electronics.

[10]  S. Sathiakumar,et al.  Harmonic analysis of nondeterministic switching methods for DC-DC power converters , 2000 .

[11]  Andrzej M. Trzynadlowski,et al.  Analysis of power and power spectral density in PWM inverters with randomized switching frequency , 2002, IEEE Trans. Ind. Electron..

[12]  Frede Blaabjerg,et al.  Random pulse width modulation techniques for converter fed drive systems-a review , 1993, Conference Record of the 1993 IEEE Industry Applications Conference Twenty-Eighth IAS Annual Meeting.

[13]  Shu Yuen Ron Hui,et al.  A comparison of nondeterministic and deterministic switching methods for DC-DC power converters , 1998 .

[14]  Takashi Kimura,et al.  A class-D amplifier using a spectrum shaping technique [audio power amplifier] , 2004, Proceedings of the IEEE 2004 Custom Integrated Circuits Conference (IEEE Cat. No.04CH37571).

[15]  Terri S. Fiez,et al.  A noise-shaped switching power supply using a delta-sigma modulator , 2004, IEEE Transactions on Circuits and Systems I: Regular Papers.

[16]  Henry Shu-Hung Chung,et al.  A comparative study of carrier-frequency modulation techniques for conducted EMI suppression in PWM converters , 2002, IEEE Trans. Ind. Electron..

[17]  Keith Bryan Hardin,et al.  Spread spectrum clock generation for the reduction of radiated emissions , 1994, Proceedings of IEEE Symposium on Electromagnetic Compatibility.

[18]  J. Nieznanski,et al.  Shaping the SPL spectra of the acoustic noise emitted by inverter-fed induction motors , 2003, IECON'03. 29th Annual Conference of the IEEE Industrial Electronics Society (IEEE Cat. No.03CH37468).

[19]  Dan Y. Chen,et al.  Reduction of power supply EMI emission by switching frequency modulation , 1993 .

[20]  R. Schreier,et al.  Delta-sigma data converters : theory, design, and simulation , 1997 .

[21]  Michael Møller Bech.  Analysis of Random Pulse-Width Modulation Techniques for Power Electronic Converters , 2000 .

[22]  F. Blaabjerg,et al.  A methodology for true comparison of analytical and measured frequency domain spectra in random PWM converters , 1998, PESC 98 Record. 29th Annual IEEE Power Electronics Specialists Conference (Cat. No.98CH36196).

[23]  John T. Boys,et al.  Spread spectrum switching: low noise modulation technique for PWM inverter drives , 1992 .

[24]  Thomas G. Habetler,et al.  Angle controlled current regulated rectifiers for AC/AC converters , 1989 .

[25]  Andrzej M. Trzynadlowski,et al.  Optimization of switching frequencies in the limited-pool random space vector PWM strategy for inverter-fed drives , 2001 .