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US 2008/0290949 A1Published application
Apparatus and method for asymmetric charge pump for an audio amplifier
AssigneeNational Semiconductor Corporation
InventorsHuaijin Chen, Marcellus Chen, Ansuya P. Bhatt, Raminder Jit Singh
Life of this patent
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Abstract
An audio amplifier with an integrated asymmetric charge pump is provided. The audio amplifier receives VDD and VSS as power supply signals. The integrated charge pump is arranged to provide VSS from VDD, such that VSS is a negative voltage that is lower in magnitude than VDD.
Claims20
A circuit for audio amplification, comprising:
- an audio amplifier having at least a first input, a second input, a VDD input, a VSS input, and an output, wherein the audio amplifier is arranged to receive an audio signal at the first input of the audio amplifier, to receive a first power supply signal at the VDD input, and to drive a speaker load at the output of the audio amplifier;
- and
- a converter having at least:
- an output that is coupled to the VSS input of the audio amplifier, and an input, wherein the converter is arranged to receive the first power supply signal at the input of the converter, and to provide a negative supply voltage at the output of the converter such that the negative supply voltage has the opposite polarity of the first supply voltage and a lesser magnitude than the first supply voltage.
1 more element
A circuit for audio amplification, comprising:
- an audio amplifier having at least a first input, a second input, a VDD input, a VSS input, and an output, wherein the audio amplifier is arranged to receive an audio signal at the first input of the audio amplifier, to receive a first power supply signal at the VDD input, and to drive a speaker load at the output of the audio amplifier;
- and
- an asymmetric charge pump integrated with the audio amplifier, wherein the asymmetric charge pump has at least:
- an output that is coupled to the VSS input of the audio amplifier, and an input, wherein the converter is arranged to receive the first power supply signal at the input of the asymmetric charge pump, and to provide a negative supply voltage at the output of the asymmetric charge pump such that the negative supply voltage has the opposite polarity of the first supply voltage and a lesser magnitude than the first supply voltage.
1 more element
A method for audio amplification, comprising:
- converting a positive power supply signal into a negative power supply signal such that the negative power supply signal is opposite in polarity to the positive power supply signal and lesser in magnitude than the power supply signal;
- providing the positive power supply signal as a positive power supply for an audio amplifier;
- and
- providing the negative power supply signal as a negative power supply for the audio amplifier.
1 more element
Dependencies are inferred from the claim text.