Constant Switching Frequency Self-Oscillating Controlled Class-D Amplifiers

Research output: Contribution to journalJournal articleResearchpeer-review

1476 Downloads (Pure)

Abstract

The self-oscillating control approach has been used extensively in class-D amplifiers. It has several advantages such as high bandwidth and high audio performance. However, one of the primary disadvantages in a self-oscillating controlled system is that the switching frequency of the amplifier varies with the ratio of the output voltage to the input rail voltage. In other words, the switching frequency varies with the duty cycle of the output. The drop in the frequency results in lower control bandwidth and higher output voltage ripple, which are undesirable. This paper proposes a new self-oscillating control scheme that maintains a constant switching frequency over the full range of output voltage. The frequency difference is processed by a compensator whose output adjusts the total loop gain of the control system. It has been proven by simulation that a con-stant switching frequency self-oscillating converter is achieved and the proposed control circuit performs
satisfactorily.
Original languageEnglish
JournalElektronika ir Elektrotechnika
Volume20
Issue number6
Pages (from-to)84-88
ISSN1392-1215
DOIs
Publication statusPublished - 2014

Keywords

  • Power amplifiers
  • Frequency control
  • Voltage control
  • Power electronics

Cite this

@article{c9c90c822c1842c79b24e3d3abed0e87,
title = "Constant Switching Frequency Self-Oscillating Controlled Class-D Amplifiers",
abstract = "The self-oscillating control approach has been used extensively in class-D amplifiers. It has several advantages such as high bandwidth and high audio performance. However, one of the primary disadvantages in a self-oscillating controlled system is that the switching frequency of the amplifier varies with the ratio of the output voltage to the input rail voltage. In other words, the switching frequency varies with the duty cycle of the output. The drop in the frequency results in lower control bandwidth and higher output voltage ripple, which are undesirable. This paper proposes a new self-oscillating control scheme that maintains a constant switching frequency over the full range of output voltage. The frequency difference is processed by a compensator whose output adjusts the total loop gain of the control system. It has been proven by simulation that a con-stant switching frequency self-oscillating converter is achieved and the proposed control circuit performs satisfactorily.",
keywords = "Power amplifiers, Frequency control, Voltage control, Power electronics",
author = "Khiem Nguyen-Duy and Arnold Knott and Andersen, {Michael A. E.}",
year = "2014",
doi = "10.5755/j01.eee.20.6.7273",
language = "English",
volume = "20",
pages = "84--88",
journal = "Elektronika ir Elektrotechnika",
issn = "1392-1215",
publisher = "Kauno Technologijos Universitetas",
number = "6",

}

Constant Switching Frequency Self-Oscillating Controlled Class-D Amplifiers. / Nguyen-Duy, Khiem; Knott, Arnold; Andersen, Michael A. E.

In: Elektronika ir Elektrotechnika, Vol. 20, No. 6, 2014, p. 84-88.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Constant Switching Frequency Self-Oscillating Controlled Class-D Amplifiers

AU - Nguyen-Duy, Khiem

AU - Knott, Arnold

AU - Andersen, Michael A. E.

PY - 2014

Y1 - 2014

N2 - The self-oscillating control approach has been used extensively in class-D amplifiers. It has several advantages such as high bandwidth and high audio performance. However, one of the primary disadvantages in a self-oscillating controlled system is that the switching frequency of the amplifier varies with the ratio of the output voltage to the input rail voltage. In other words, the switching frequency varies with the duty cycle of the output. The drop in the frequency results in lower control bandwidth and higher output voltage ripple, which are undesirable. This paper proposes a new self-oscillating control scheme that maintains a constant switching frequency over the full range of output voltage. The frequency difference is processed by a compensator whose output adjusts the total loop gain of the control system. It has been proven by simulation that a con-stant switching frequency self-oscillating converter is achieved and the proposed control circuit performs satisfactorily.

AB - The self-oscillating control approach has been used extensively in class-D amplifiers. It has several advantages such as high bandwidth and high audio performance. However, one of the primary disadvantages in a self-oscillating controlled system is that the switching frequency of the amplifier varies with the ratio of the output voltage to the input rail voltage. In other words, the switching frequency varies with the duty cycle of the output. The drop in the frequency results in lower control bandwidth and higher output voltage ripple, which are undesirable. This paper proposes a new self-oscillating control scheme that maintains a constant switching frequency over the full range of output voltage. The frequency difference is processed by a compensator whose output adjusts the total loop gain of the control system. It has been proven by simulation that a con-stant switching frequency self-oscillating converter is achieved and the proposed control circuit performs satisfactorily.

KW - Power amplifiers

KW - Frequency control

KW - Voltage control

KW - Power electronics

U2 - 10.5755/j01.eee.20.6.7273

DO - 10.5755/j01.eee.20.6.7273

M3 - Journal article

VL - 20

SP - 84

EP - 88

JO - Elektronika ir Elektrotechnika

JF - Elektronika ir Elektrotechnika

SN - 1392-1215

IS - 6

ER -