AN1042/D High Fidelity Switching Audio Amplifiers Using TMOS Power MOSFETs Prepared by: Donald E.
Pauly ON Semiconductor Special Consultant http://onsemi.com APPLICATION NOTE With the introduction of complementary bipolar power transistors in the late 1960s, switching amplifiers became theoretically practical.
At low frequencies, bipolar transistors have switching efficiencies of 99% and will directly drive a low impedance speaker filter.
The requirement for switching frequencies above 100 kHz