Amplifier with power supply switching
AssigneeNippon Gakki Seizo Kabushiki Kaisha
InventorKenji Yokoyama
Life of this patent
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Abstract
A power amplifier is provided with a peak-holding means for holding, for a given period of time, a peak value of an input signal or an output signal of a power amplifying element there of and is provided also with a switching means for switching, to a selected value in accordance with an output from the peak-holding means, a dc power supply voltage which is supplied to said power amplifying elements. Such amplifier is able to enhance the power efficiency of the power amplifier as well as to reduce switching noises and to reduce the development of distortions.
Claims26
An amplifier with power supply switching, comprising:
- an amplifying element for amplifying the input signal to said amplifier;
- a peak-holding circuit for holding, for a predetermined period of time, a peak value of a signal which varies in accordance with said input signal;
- and
- a switching circuit for selectively supplying to said amplifying element a supply voltage level selected from among at least two available supply voltage levels in accordance with a level of an output of said peak-holding circuit.
An amplifier with power supply switching, comprising:
- an amplifying element for amplifying an input signal to said amplifier;
- a first comparator for comparing said input signal with a first reference signal;
- a peak-holding circuit for holding, for a predetermined period of time, a peak value of an output of said first comparator;
- and
- a switching circuit for selectively supplying to said amplifying element with a supply voltage among a plurality of supply voltages in accordance with a level of an output of said peak-holding circuit.
An amplifier, comprising:
- an amplifying element for amplifying an input signal;
- a power supply capable of providing at least two different voltage levels to the amplifying element;
- a peak-holding circuit for providing a peak signal corresponding to a peak of an output signal of the amplifying element and holding that peak value for a predetermined period of time;
- a comparator for comparing the peak signal with a predetermined threshold level and providing a comparison signal indicative of the comparison result;
- and
- a switching circuit for selecting, responsive to the comparison signal, one of the at least two different voltage levels of the power supply for application to the amplifying element, whereby the voltage applied to the amplifying element is increased to the higher of the at least two voltage levels as necessary to avoid distortion of an amplified signal and decreased to the lower of the at least two voltage levels to enhance operating efficiency of the amplifier when an increased voltage is not required to prevent distortion, the frequency of switching between power supply voltage levels being minimized by the predetermined holding time period provided by the peak-holding circuit.
Dependencies are inferred from the claim text.