Method and apparatus for controlling a selectable voltage audio power output stage

An audio amplifier, power amplifier technology, applied in low frequency amplifiers, improving amplifiers to improve efficiency, improving amplifiers to reduce nonlinear distortion, etc., can solve problems such as limiting available output power, unusable power, and waste of power

Inactive Publication Date: 2009-08-12
CIRRUS LOGIC INC
View PDF0 Cites 32 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The output stage of the device has a linear power amplifier which wastes power at low signal level output stages because the voltage drop of the operating output transistors plus the output voltage is equal to the constant rail voltage of the power supply
[0003] Even though the current in the inverter is reduced at low signal amplitudes, more power is still wasted dissipating in the output transistors than is deliv

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method and apparatus for controlling a selectable voltage audio power output stage
  • Method and apparatus for controlling a selectable voltage audio power output stage
  • Method and apparatus for controlling a selectable voltage audio power output stage

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0014] The present invention includes a control method and device for selecting a power supply voltage supplied to an audio power amplifier. The power supply voltage provided to the final power amplifier is optional and set to be consistent with the expected or actual audio signal level being amplified, so that the signal amplitude does not require the maximum power supply voltage, so the power supply voltage is reduced to save energy. For example, if a signal with a maximum amplitude of -6dB and an instantaneous peak value of 0dB is amplified, the power supply voltage of the final stage amplifier can be reduced to 1 / 2 of the above-mentioned peak value without clipping. As a result, power consumption is reduced by a factor of four, and power loss is reduced to at least the level of an amplifier without an optional power supply. This method of controlling the selected supply voltage can delay or suppress the increase in the volume signal until the selected supply voltage has st...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

A method and apparatus for controlling a selectable voltage audio power output stage provides a mechanism for raising the selected power amplifier output voltage in time for the arrival of signal peaks to avoid clipping. Signal peaks may either be delayed by delaying an increase in volume control level or enabling signal compression for a predetermined time period, so that sufficient time is provided for the amplifier power supply to stabilize at a higher operating voltage when an increase of power supply voltage is selected. Alternatively, a signal level may be determined at an upstream source, such as a decoder or filter that provides information in sufficient advance of the arrival of the peaks, and used to control the power supply selection, so that the higher power supply voltage level is selected in advance of arrival of the signal peaks that would otherwise cause clipping at the power amplifier output.

Description

technical field [0001] The present invention relates to an audio power output stage of a consumer electronic device, and more particularly, to a control circuit for selecting a power supply voltage of an audio power stage. Background technique [0002] On battery-powered consumer audio equipment, a power output amplifier is typically used to drive a pair of headphones or speakers using battery power. The output stage of the device has a linear power amplifier which wastes power at low signal level output stages because the voltage drop of the active output transistors plus the output voltage equals the constant rail voltage of the power supply. [0003] Even though the current in the inverter is reduced at low signal amplitudes, more power is still wasted dissipating in the output transistors than is delivered to the load. Battery power in linear amplifier circuits is usually only reduced by reducing the supply voltage, which limits the available output power, and may not b...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): H03F1/02H03F1/32H03F3/181
Inventor 约翰·L·梅安森约翰·克里斯托夫·塔克
Owner CIRRUS LOGIC INC
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap