DIGITAL AMPLIFIER

摘要

The disclosed amplifier can reduce both overcurrent in output-current and resonance current detection time, minimises output suspension, and is capable of more appropriate current control operations. A digital amplifier has: in the output portion of switch elements (Q1, Q2), an overcurrent detection circuit (19) for detecting overcurrent, which is equal to or exceeds a specified value, in the output current; a phase advance circuit (22) which advances the phase of an overcurrent detection signal; and a resonance current detection circuit (21) which detects resonance current equal to or exceeding a specified value relating to the output current when resonance is generated at an output filter (15). When an abnormal state is detected in the output current on the basis of the overcurrent detection signal or a resonance current detection signal, a drive circuit (12) carries out current limiting operations by turning a drive signal to OFF and stopping the switching operation of the switching elements (Q1, Q2).