Buck Converter vs. Boost Converter: Key Differences

This article compares buck converters and boost converters, highlighting their key differences. Both are DC-to-DC converters, but they differ in how they handle voltage and current between the input and output.

Introduction

Buck and boost converters fall under two main topologies: inverting and non-inverting. In inverting types, the output voltage polarity is opposite to the input, whereas non-inverting types maintain the same polarity.

These converters act as switching regulators, employing a switching element (typically one or two MOSFETs) and an energy storage device (like an inductor) to efficiently regulate the input voltage, either reducing it to a lower output voltage or increasing it to a higher one.

Buck Converter

• A buck converter is also known as a step-down converter.
• The circuit diagram of a buck converter is shown in the image above.
• It reduces the input voltage and increases the input current.
• Therefore, Vin > Vout and Iin < Iout

Boost Converter

• A boost converter is also known as a step-up converter.
• The circuit diagram of a boost converter is shown in the image above.
• It increases the input voltage and reduces the input current.
• Therefore, Vin < Vout and Iin > Iout