Zero-voltage switched FM-PWM converter

A zero-voltage switched FM-PWM regulated D-C to D-C converter circuit having an unregulated input line and a regulated output line, said converter circuit operatively connectable to a controller which controls the regulation and zero-voltage switching of said converter circuit, said converter circuit comprising:

• an input filter capacitor to filter input voltage from said input line;
• a first inductor coupled to receive input current from said input capacitor and said input line;
• an output filter capacitor;
• a diode;
• a switching means coupled to said first inductor and having a conducting state and non-conducting state, said switching means for controlling the transfer of power from said first inductor to the output line and to said output filter capacitor through said diode;
• a discrete capacitor connected directly across the switching means to reduce turn-off transient power dissipation in the switching means;
• a first voltage sensing means coupled to said switching means for providing an output signal indicative of the voltage across said switching means, said output signal used to cause the controller to turn on the switching means when essentially a zero voltage is present across said switching means;
• and
• a second voltage sensing means to sample the output line voltage to provide a signal to cause the controller to control the switching means conduction on-time and switching frequency to maintain the output line voltage essentially constant;
• wherein said converter circuit is non-resonant.

A zero-voltage switched FM-PWM regulated D-C to D-C converter circuit having an unregulated input line and a regulated output line, said converter circuit operatively connectable to a controller which controls the regulation and zero-voltage switching of said converter circuit, said converter circuit comprising:

• an input filter capacitor to filter input voltage from said input line;
• an output filter capacitor;
• a diode;
• a transformer to provide DC isolation between the input line and the output line having a primary winding and a secondary winding, the primary winding coupled to said input line and the secondary winding coupled to the output filter capacitor and to the output line through said diode;
• a first switching means coupled to said transformer and having a conducting state and anon-conducting stat, said first switching means for controlling the transfer of power from a primary winding of said transformer to said secondary winding;
• a capacitor connected directly across the first switching means to reduce turn-off transient power dissipation in the first switching means;
• a first voltage sensing means coupled to said first switching means for providing an output signal indicative of the voltage across said first switching means and used to cause the controller to turn on the first switching means when essentially a zero voltage is present across said first switching means;
• and
• a second voltage sensing means coupled to sample the output line voltage to provide a signal to cause the controller to control the first switching means conduction on-time and switching frequency to maintain the output line voltage essentially constant;
• wherein said converter circuit is non-resonant.