A high power density VHSIC power supply

A regulated 3.3 V, 10 A supply that combines several innovative approaches is described. The power stage is based on the Cuk converter which allows a very effective application of the integrated-magnetics technique: all magnetic elements (input and output filtering inductors, transformer) are combined on a single magnetic core resulting in a very compact and efficient structure. Moreover, input and output current ripples are reduced to small residual values. By addition of resonant elements, the converter is operated as multiresonant (MR) so that switching losses are reduced significantly. Power density is improved even further because the converter is operated above 1 MHz, which allows the use of an EE-16 core for the integrated-magnetics structure. A novel ultra-low-on-resistance MOS rectifier is used to reduce the rectifier conduction loss, which is critical for high efficiency of the low voltage supply. Also, the controllable rectifier improves the performance of the MR power stage.