Patent ID: 7619481

Claim:
A power amplifier for driving a load connected between an first output terminal and a second output terminal, comprising: a first output amplifier section for outputting a predetermined signal to said load from said first output terminal and a second output amplifier section for outputting a signal, having an opposite phase to the predetermined signal from said first output amplifier section, from said second output terminal; an output amplifier control section for controlling operation of said first output amplifier section and said second output amplifier section; a current detection section for detecting overcurrent flowing to at least either said first output amplifier section or said second output amplifier section is greater than or equal to a set value; a voltage detection section for detecting a voltage at said first output terminal and said second output terminal is greater than or equal to a set value; a control section for stopping the operation of said first and second output amplifier section by controlling said output amplifier control section when generation of said over-current is detected by said current detection section and for maintaining the stopped operation of said first and second output amplifier section even though generation of said over-current is not detected at said current detection section when a voltage greater than or equal to said set value is detected by said voltage detection section; and a terminal voltage detection section for detecting terminal voltage between said first output terminal and said second output terminal is greater than or equal to a set value; detection sensitivity of generation of said over-current is lowered at said current detection section when a terminal voltage greater than or equal to said set value is detected by said terminal voltage detection section.