Patent ID: 7893764

Claim:
A power amplifier having class-D amplifiers of two channels built therein, comprising: a first class-D amplifier including a low-pass filter provided in an output section thereof; a first hot-side output terminal; a first ground-side output terminal; a second class-D amplifier including a low-pass filter provided in an output section thereof; a second hot-side output terminal; a second ground-side output terminal; and a common mode choke coil device including four coils wound on a common core in a same direction, each of the four coils having first and second ends, wherein hot-side outputs of the first and second class-D amplifiers are connected to respective ones of the first ends of two of the four coils, and the first and second hot-side output terminals are connected to respective ones of the second ends of the two coils, and wherein ground-side outputs of said first and second class-D amplifiers are connected to respective ones of the first ends of remaining two of the four coils, and the first and second ground-side output terminals are connected to respective ones of the second ends of the remaining two coils.