Plenary Lecture 1: Efficient isolated DC-DC converters with maximum integration scale

摘要

Certain system or safety requirements may impose the use of isolated DC-DC converters for powering the electronic circuitry in various applications. Typical examples are the power supplies in central-office ADSL and VDSL telecommunication equipment or the power supply units in Power-over-Ethernet devices. Widely used isolated converter topologies are the flyback, the forward and the combined forward-flyback architectures, where the driving electronics at the primary side of the pulse transformer and the rectifying electronics at the secondary side are employing discrete power transistors and/or diodes. This talk will show how the electronics at both sides of the pulse transformer can be integrated into a monolithic IC in an advanced smart-power technology, leading to a very compact isolated converter solution consisting of only 4 components: the pulse transformer, 2 chips (1 at each side) and an opto-coupling device, and this for output power levels up to 100W. New techniques for reducing the silicon cost and for achieving maximum power efficiency will be presented. This includes the use of active-clamping H-bridge driving, synchronous rectification with reduced driving voltage and active voltage clamping. Specific monolithic IC implementations for telecommunication applications will be analyzed and experimental data will be discussed. Finally, this monolithic approach will be benchmarked against existing discrete solutions.