US Patent 7145786 Point of load sine amplitude converters and methods

In a preferred embodiment, a Sine Amplitude Converter (“SAC”) method and apparatus for VTMs converts a DC input voltage to a DC output voltage using a fixed transformation ratio at a frequency locked to a resonance. The SAC uses a resonant circuit including a transformer and complementary primary switches operating with balanced switching and a high power conversion duty cycle (e.g., above 94%) to perform high frequency, low noise, single stage power processing. The resonant circuit may have a low Q while enhancing conversion efficiency. Common-mode noise may be effectively reduced using symmetrical resonant power trains.