An On-Board Step-Down DC/DC Converter for System-On-Chip Power-Supply Strategy

Battery-powered mobile systems face new challenges in term of power delivery and management strategy. Multiple power management circuits are now replaced by only one or two voltage level delivery as system-on-chips embed more and more power domains from a unique voltage supply. Board carrying SoCs are required to deliver this voltage supply with the highest possible efficiency over a wide load range, tremendous transient performances and the smallest footprint. A companion voltage regulator is proposed to supply the ever-demanding SoCs at the best trade-off between the latter antagonist requirements. Sliding-mode control enables transient performances at medium switching frequency operation. EMI stringent specifications are served by an analogue assist circuit that synchronizes the switching frequency. The design of the DC/DC voltage regulator is detailed and experimental measurement are discussed.