Selecting 12V Regulator for Mosfet Driver Ics

Level 1
Level 1
Hello friends,

I have little confusion while designing the controller board for mosfets.

I am using 3 x IRS21867S 4A Source/Sink Gate drivers with 6 mosfets (brushless driver). How much current would be needed for this IC's regulator?

12V 1Ampere regulator would be enough? Or should we use 12A (4A x 3) regulators? That peak currents are used by bootstrap capacitor or voltage regulator's bulk capacitors?

For this uncertainty I am usually trying to use highest current output regulators but I guess not much true. What can happen if I use 100mA regulator? At past when I used low current regulators I saw some unhealthy problems at drivers.

Regards
1 Solution

Re: Selecting 12V Regulator for Mosfet Driver Ics

Moderator
Moderator
Hi,

The total current required by the gate driver circuit can be calculated as follows,

Total Power or the driver power, Pdrive= ((Qg*Fsw) + Iqd) * Vg
where,
Qg = gate charge of the MOSFET used for this application
Fsw = switching frequency
Iqd = Quiescent current (for both Vbs and Vcc )
Vg = Drive voltage.

For quiescent current values, please refer to the below image,

Current required by the IC's regulator, I = Pdrive/Vg.

After calculating the total current multiply it by 3 so that we can arrive at the total current.

Please refer to the following app note for more details,

https://www.infineon.com/dgdl/Infineon-Use_Gate_Charge_to_Design_the_Gate_Drive_Circuit_for_Power_MO...

Please let me know if this explanation has helped you in selecting the right regulator for your application.

Regards,
Abhilash P

Re: Selecting 12V Regulator for Mosfet Driver Ics

Moderator
Moderator
Hi,

The total current required by the gate driver circuit can be calculated as follows,

Total Power or the driver power, Pdrive= ((Qg*Fsw) + Iqd) * Vg
where,
Qg = gate charge of the MOSFET used for this application
Fsw = switching frequency
Iqd = Quiescent current (for both Vbs and Vcc )
Vg = Drive voltage.

For quiescent current values, please refer to the below image,

Current required by the IC's regulator, I = Pdrive/Vg.

After calculating the total current multiply it by 3 so that we can arrive at the total current.

Please refer to the following app note for more details,

https://www.infineon.com/dgdl/Infineon-Use_Gate_Charge_to_Design_the_Gate_Drive_Circuit_for_Power_MO...

Please let me know if this explanation has helped you in selecting the right regulator for your application.

Regards,
Abhilash P