Patent attributes
A Class D amplifier capable of setting restraint power is provided, which comprises: an audio amplification unit, a pulse width modulation (PWM) unit, a first pre-drive unit, a second pre-drive unit, a first power transistor set, a second power transistor set and a power restraint unit. The power restraint unit has a comparator circuit and a power restraint circuit. The comparator circuit is configured to compare the level of first/second amplified audio signals against the level of a first reference voltage that is externally settable. When the high level of the first/second amplified audio signals is higher than the level of the first reference voltage, the comparator circuit outputs a first comparison signal and a second comparison signal to the power restraint circuit to restrain the power.