What is a practical way to drive high side MOSFET or IGBT transistors?

What is a practical way to drive high side MOSFET or IGBT transistors?

A pulse transformer is very practical, especially if the drive must be galvanically isolated from the door for safety reasons. If the pulse width varies a lot, you may need some components for continuous restoration on the door. Otherwise you will simply need a series resistor and maybe two back-to-back Zener diodes for voltage maintenance. all this costs almost nothing, whereas a dedicated high side driver can be expensive.

use opto-isolators is a good method. it does not matter to them the voltage difference between the source and the switch. If you have very high voltages, you can power the optical signal on a fiberglass at a distance.

Regarding the source of power for the gate, you can use batteries or a well-insulated transformer or photovoltaic cells and bright light.

with a dedicated high-side driver chip. it’s the best method nowadays. Ten years ago, it would have been typical to build your own high-side control circuit from components. One of the methods is a gate control transformer, where the gate control signal goes through a transformer (usually a small ferrite core) with the secondary directly connected to the gate, often with only a few components on the secondary for the protection against overvoltages and the damping of the resonance. in this design, most of the conductor is on the low side, driving the isolated gate control transformer primary. This is the simplest method, but it only works in cases where the gate control signal can be practically transferred via a transformer. thus, it must be a relatively symmetrical alternative waveform and repeating itself regularly over a reasonable frequency range. This also has the advantage of being able to drive multiple switching devices from a transformer using a low-side drive in some designs. you can actually drive a full H bridge with a bipolar down-side driver and a transformer (with four secondary) if you do not need a timeout.

The other typical approach is to use an insulated and floating gate control power supply (a mini-DC-DC converter – many ways to manage it), with an opto-isolator transmitting the gate signal from the control circuit to the side. low voltage floating support. conductive circuit. This allows arbitrary gate control regardless of signal symmetry, duty cycle, or frequency (within reasonable limits). This is much more complicated to build, but eliminates most of the limitations of door-controlled transformers.

Nowadays, however, dedicated high-side control chips are widely available and handle most of these problems internally. they usually need some external passive components for their floating power, but they do everything else automatically. It makes little sense to build a high-side driver from components. Unless a simple grid control transformer does the trick, a high-performance side control chip is the .

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