AN938 application note describes the design of L4973 3.5A high efficiency DC-DC converter, which uses BCD60 II technology and adopts continuous mode step-down topology. The input voltage range is 8V-55V, and the output voltage is 60V in no-load condition. The internal current limiting and thermal shutdown are considered as standard protection functions for safe load supply, and an oscillator with voltage feed-forward improves line regulation and overall control loop. The soft-start function prevents output overvoltage at turn-on, and the synchronization function can reduce EMI problems in multi-output power supplies. The inhibit function, introduced for power management in equipment having standby features, when active (high), reduces device power consumption by a few tens of µA.