Driver for a high efficiency, high frequency Class-D power amplifier
First Claim
1. A driver for a high efficiency Class-D voltage-switching power amplifier of the type having first and second switching devices connected in series in a half-bridge configuration and including an output resonant circuit at the junction between said first and second switching devices, said output resonant circuit comprising a capacitance connected in series with an inductance, said first and second switching devices each having an input capacitance and an output capacitance, said driver comprising:
- sinewave signal generating means for providing an input sinewave power signal to said firs and second switching devices so as to produce sinusoidal voltage signals of predetermined amplitude at the inputs of said first and second switching devices in order to control the transition time between turn-off of one of said first and second switching devices and turn-on of the other one of said switching devices in order to ensure that the output capacitance of said other one of said switching devices is substantially discharged and further that turn-on of said one of said switching devices occurs when there is substantially zero voltage thereacross and substantially zero current therethrough, thereby resulting in substantially lossless switching; and
oscillator means for driving said sinewave signal generating means.
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Abstract
A driver circuit for a voltage-switching, high frequency Class-D power amplifier provides an input sinewave power signal and controls the transition time between switching the two active devices thereof, resulting in substantially lossless switching. The transition time is optimized by controlling the amplitude of the voltage signals at the inputs of the two active devices, depending on the output capacitance of the switching devices, the threshold voltage of the switching devices, the power output requirement, and the impedance of the resonant load network of the Class-D power amplifier.
105 Citations
10 Claims
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1. A driver for a high efficiency Class-D voltage-switching power amplifier of the type having first and second switching devices connected in series in a half-bridge configuration and including an output resonant circuit at the junction between said first and second switching devices, said output resonant circuit comprising a capacitance connected in series with an inductance, said first and second switching devices each having an input capacitance and an output capacitance, said driver comprising:
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sinewave signal generating means for providing an input sinewave power signal to said firs and second switching devices so as to produce sinusoidal voltage signals of predetermined amplitude at the inputs of said first and second switching devices in order to control the transition time between turn-off of one of said first and second switching devices and turn-on of the other one of said switching devices in order to ensure that the output capacitance of said other one of said switching devices is substantially discharged and further that turn-on of said one of said switching devices occurs when there is substantially zero voltage thereacross and substantially zero current therethrough, thereby resulting in substantially lossless switching; and oscillator means for driving said sinewave signal generating means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification