Patent ID: 8350538

Claim:
A switching DC-to-DC converter for providing power from a DC voltage source connected between an input terminal and a common terminal to a DC load connected between an output terminal and said common terminal said converter comprising: an input switch with one end connected to said input terminal; an inductor with one end connected to said output terminal; a capacitor with one end connected to another end of said input switch and another end connected to said inductor another end thereof; a complementary input switch with one end connected to said common terminal and another end connected to said one end of said capacitor; a resonant inductor with one end connected to said another end of said capacitor; an output switch with one end connected to said common terminal and another end connected to said resonant inductor another end thereof; switching means for keeping said input switch ON for a duration of time interval DT S , keeping it OFF for a complementary duty ratio interval D′T S , where D is a duty ratio and D′ is a complementary duty ratio within one complete and controlled switch operating cycle T S ; wherein said input switch, and said complementary input switch are semiconductor switching devices such as bipolar transistors or MOSFET transistors; wherein said output switch is a diode, having said one end of the output switch being an anode and said another end being a cathode, capable of conducting the current in one direction while in an ON-state, and sustaining voltage in opposite direction, while in an OFF-state; wherein said semiconductor rectifier anode end is connected to the common terminal and the cathode end is connected to said resonant inductor another end so as to result in positive output DC voltage between output terminal and common terminal for the positive DC source between input terminal and common terminal; wherein said switching means include precise electronically controlling operation of said complementary input switch relative to said input switch, whereby two transition intervals, a first transition interval and a second transition interval are created during which both said input switch and said complementary input switch are turned OFF during each successive said switch operating cycle T s , wherein said first and said second transition intervals are short compared to said switch operating cycle T S ; wherein a DC-to-DC voltage conversion ratio of said converter depends linearly on said operating duty ratio D; whereby within a whole said duty ratio D, voltages across said input switch and said complementary input switch are equal to a voltage of said DC voltage source, and whereby within a whole said duty ratio D, voltage across said output switch is equal to voltage between said output terminal and said common terminal divided by the operating duty ratio D resulting in reduced and low voltage stress for higher duty ratios.