Patent ID: 7205834
Filing Date: 2007-04-17
Classification: H03F

Abstract:
1. A power amplifier comprising: a first amplification circuit connected at an output terminal thereof to one end of a load and for making noninverting-amplification of an input signal; a second amplification circuit connected at an output terminal thereof to an other end of the load and for making inverting-amplification of an input signal; deviation detecting means for detecting a deviation between potentials at the output terminals of the first and second amplification circuits; and operation stopping means which works according to a deviation detection output from the deviation detecting means to stop the first and second amplification circuits from operating, wherein: the first amplification circuit includes: first pulse width modulation means for converting the input signal into a first pulse width modulation signal whose pulse width corresponds to a quantization level of the input signal, and a first switching circuit for performing a switching operation, according to a drive pulse from the first pulse width modulation means, wherein the output terminal thereof is connected to one end of the load; and the second amplification circuit includes: second pulse width modulation means for converting the input signal into a second pulse width modulation signal whose pulse width corresponds to two's complement of the quantization level of the input signal, and a second switching circuit for performing a switching operation, according to a drive pulse from the second pulse width modulation means, wherein the output terminal thereof is connected to the other end of the load.