Skip to Content

Linear and Switched Mode Converters Basics

Last modified by Microchip on 2025/01/03 10:46

Introduction

Power converters are electronic systems designed to convert electrical power from one form to another. They are classified based on the type of input and output they handle:

  1. DC-DC Converters: Convert Direct Current (DC) input to a regulated DC output
  2. DC-AC Converters (Inverters): Convert DC input to Alternating Current (AC) output
  3. AC-DC Converters (Rectifiers): Convert AC input to a regulated DC output
  4. AC-AC Converters: Modify the frequency or voltage of an AC input to an AC output

Power Converter Classifications

Linear Converters

  • Operate by dissipating excess voltage as heat through a pass element (Metal–Oxide–Semiconductor Feld-Effect Transistor (MOSFET) or transistor)
  • Simple design but limited to step-down applications
  • Efficiency depends on input-output voltage ratio: Efficiency = (Vout / Vin) x 100%

Switched-Mode Converters (Switchers)

  • Use high-frequency switching to regulate output
  • Efficiency is higher, especially for large voltage differentials
  • Support multiple topologies:
    • Non-Isolated: Direct connection between input and output ground
      • Buck (Step-down): Reduces voltage
      • Boost (Step-up): Increases voltage
      • Buck-Boost: Combines buck and boost for step-up/step-down capability
    • Isolated: Uses a transformer for input-output isolation
      • Common in high-voltage applications, ensuring safety and galvanic isolation

Linear vs Switcher

Back to Top