Descriptions of Gate Drivers

Gate driver Power Management Integrated Circuits (PMICs) are devices designed to handle various functions needed to connect signals from a control device to the semiconductor devices (like FETs or IGBTs) in a power conversion setup. These functions might include isolation, amplification, reference shifting, bootstrapping, and more. The exact features of each device can vary, depending on the type of semiconductor it’s meant to drive.

Frequently Asked Questions

What does a gate driver do?

A gate driver is like a power amplifier. It takes a small, low-power signal from a controller IC and turns it into a high-current signal that drives the gate of a high-power transistor, such as an IGBT or a power MOSFET.

What happens when a gate drive is applied?

When a gate drive is applied, the gate driver sends current to the FET gate to deal with the input capacitance. The more current the driver provides, the quicker the MOSFET turns on. But it’s not instant. Usually, it takes between 10 ns and 50 ns for a power MOSFET to fully turn on.

What is an active gate driver?

Active gate driving is a bit different from the usual method. Instead of just applying a constant voltage (like 5 V) to turn the gate on and 0 V to turn it off, an active gate driver shapes the gate voltage to improve the switching waveforms.

Do I need a gate driver?

Yes, you usually do. A digital system, like a microcontroller (MCU), often doesn’t have enough power to activate the device on its own. So, you need an interface, specifically a gate driver, between the control logic and the power switch. One of the main roles of the gate driver is to act as a level translator.

What are the different types of gate drivers?

• Low-Side Gate Drivers
• High-Side Gate Drivers
• High- and Low-Side Gate Drivers
• Half-Bridge Gate Drivers
• Full-Bridge Gate Drivers
• 3-Phase Motor Gate Drivers