Fairchild Semiconductor AN-6069 Application Note Low-Side Gate Drivers

About this manual

This document discusses the requirements for low-side gate drivers used with Power MOSFETs in applications involving clamped inductive loads, synchronous rectifiers, and pulse/gate drive transformers. It explains how drivers translate control signals into the necessary power signals to switch MOSFETs effectively.

What's inside

• Clamped Inductive Switching
• Synchronous Rectifiers
• Transformer Drive
• MOSFET Turn On Process
• MOSFET Turn Off Process
• Evaluating Drivers on the Bench
• Switching Loss Calculations

Frequently asked questions

What is the purpose of a low-side gate driver in synchronous rectifier applications?

External drivers provide high-current pulses and timing control to eliminate shoot-through and optimize efficiency.

What current source value was used in the example test circuit for the FCP20N60?

The test circuit drives the gate with a small current source of 3mA.

How is the time for interval t2 calculated during MOSFET turn-on?

The time required is found by dividing the charge Qgs2 by the driver current Ic.