Demonstration Circuit 423: 1A, 500kHz High Voltage Buck Converter using LT1956

Overview

This design document describes Demonstration Circuit 423, a monolithic step-down DC/DC switching converter featuring the LT1956. The circuit is optimized to provide a 5V output at up to 1A load current from a steady-state input range of 7.5V to 25V, with transient protection up to 60V. Operating at a constant 500kHz frequency, the design utilizes current-mode control to ensure fast transient response and loop stability using ceramic input and output capacitors. The integrated 1.5A power switch features low resistance (0.2Ω) for high efficiency. The document includes a schematic, typical performance summaries, and customization instructions for different output voltages and thermal management.

Referenced Parts