Isolated synchronous forward controller with integrated feedback loop and adjustable dead time for high efficiency DC/C converter

Inhalt:
A new highly integrated controller topology for DC/DC converters with active clamp on the primary side and synchronous rectifiers on the secondary side of the converter is presented. The controller consists of two chips; one chip on the primary side, controlling the main power switch and active clamp switch as well as second chip on the secondary side controlling synchronous rectifiers. Both chips communicate with each other by means of integrated micro transformers ensuring galvanic isolation and bi-directional signal exchange. The micro transformers offer high speed communication between the both chips. Thus, fast closed feedback loop with minimum latency can be realized when transfer error signal from the secondary to the primary side. High speed data transfer ratio from primary-to-secondary side allows precise adjustment of dead time between main switch and synchronous rectifiers. Therefore, the high speed bi-directional communication helps to elevate the bandwidth of the DC/DC converter and increase the power efficiency.