Wide input rails are common in many electronic systems including communications infrastructure, automotive, and industrial systems. Input voltages as high as 100V need to be converted to 24V/12V/5V or other lower voltages that can be used by electronic systems. This paper presents various application scenarios where high-voltage capability up to 100V is required and explains how high-voltage power management integrated circuits can reduce component count, enhance reliability, and facilitate design reuse. Real world circuit examples from communication infrastructure, industrial, automotive, and consumer electronic systems demonstrate the potential benefits.