Wolfspeed Mosfet's Gate Voltage

ysfherdem

Hi,

In this comment,

https://forum.wolfspeed.com/discussion/comment/1564#Comment_1564

The recommended gate driver operating voltages are said as 15.75/-4.2V. But in the crd_22dd12n reference design R15P21503D is used as gate driver supply.

This module has more than 5% tolerance. Why are you using this module for gate driver?

Is the load of this module bigger than 50% in the reference design?

Thanks

Forum_Moderator

Thank you for your post, it has been approved and we will respond as soon as possible.

ysfherdem

????

ysfherdem

I think Wolfspeed did it on purpose. Or not?

TBhatia

Hello ysfherdem,

You're right, this is a slightly older design and due to the lack of better gate drive power supply design at that time and simplicity of design, we understand the regulation is marginal.

We have many new designs that you can refer to obtain the regulation within +-5% and I would be happy to send you a few examples offline from other unreleased reference designs.

Alternatively, you can also refer to this application note: DESIGN OPTIONS FOR WOLFSPEED® SILICON CARBIDE MOSFET GATE BIAS POWER SUPPLIES for gate drive power supply options. Please let me know if you have any other questions!

ysfherdem

Hello TBhatia,

We have a lot of this dc/dc converter and that is why I wanted to use it. We are already using it in one of our circuits. We have not had a problem yet, but as you said we should not use this converter.

The gate voltages of Wolfspeed mosfets are really troublesome, the range is much wider in other mosfet types. However, since we have a lot of mosfets, we want to evaluate this.

I would be glad if you can send me the unreleased reference designs you have.

Thank you very much for your attention.