| 摘要 |
PURPOSE: A dynamic range compression circuit and a D class amplifier are provided to reflect amplitude change of an input signal of an input terminal maximum amplitude within an amplitude range of an output signal by optimally using an amplitude range which is able to be outputted. CONSTITUTION: An attenuator(185) drops gains of an amplifier by attenuating a signal from a predetermined node within the amplifier. An amplification unit(10) comprises first resistance(11) having a first resistance value, second resistance having a second resistance value, third resistance(13) having a third resistance value, a fourth resistance(14) having a fourth resistance value, and a differential amplifier(20). The first to 4 resistances are serially inserted between an input terminal(1) and an output terminal(2) in a power amplifier. The differential amplifier includes a grounded in-phase input terminal and a reversed phase input terminal connected to a node between the third and fourth resistances. The differential amplifier includes the output terminal connected to the output terminal of the power amplifier. |
