This design is based on Active Resonant Tank (ART) cells to achieve Zero-Voltage-Switching (ZVS) and eliminate body diode conduction in dc-dc converters with Synchronous Rectifiers (SRs). In low-output-voltage dc-dc converters, SRs are widely utilized to reduce rectifier conduction loss and improve converter efficiency. However, during switches’ transition, SRs’ parasitic body diodes unavoidably carry load current, which decreases conversion efficiency because the voltage drop across body diodes is much higher than that across SRs. Moreover, body diodes’ reverse recovery leads to increased switching losses and electromagnetic interference.
    With ART, the body diode conduction of the SR is eliminated during the switching transition from an SR to an active switch, and thus body diode reverse-recovery- related switching and ringing losses are saved. An ART cell consists of an LC resonant tank and an auxiliary switch. A resonant tank cell is charged in a resonant manner and energy is stored in the capacitor of the tank. Prior to a switching transition from an SR to an active switch, the energy stored in the tank capacitor is released and converted to inductor current, which forces the SR current changes direction to avoid conduction of the body diode and related reverse recovery when the SR turns off. Moreover, at the help of energy released from the ART, the active switch’s junction capacitance is discharged, which allows the active switch turns on at ZVS. Since energy commutation occurs only during switching transition, conduction loss in the ART cell is limited. Moreover, the auxiliary switch turns off at ZVS and the SR operates at ZVS. The concept of ART cells is design using Matlab-Simulink and simulation analysis is presented based on a synchronous buck converter. 

Reference Paper: Zero-Voltage-Switching DC–DC Converters with Synchronous Rectifiers
Author’s Name:  Hong Mao, Osama Abdel Rahman, and Issa Batarseh
Source: IEEE TRANSACTIONS ON POWER ELECTRONICS
Year: 2008
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