Feedback for a low gate driver circuit?

Thread Starter

Sweetest Fruit

Joined Jan 10, 2023
2
So I designed a circuit to drive mosfets through which high powered devices will be connected to.

These devices are mainly a led bar of (24 V, 3 A), a high powered relays (24 V, 30 A) and a dc motor (12 V, 30 A) in my lab.

The low side gate driver I choose is the UCC27517DBVT and it will be controlled by a microcontroller such as the arduino. The LED bar will be driven with pwm and the relay as a switch.

One of my concerns was the choice of mosfet I made, knowing that the one selected only dissipates 26 W and that the vgs optimal for a low RDS On is 10V and full current of ID = 40 A.
Screenshot_20230110_013640_Reddit.jpgScreenshot_20230110_013647_Reddit.jpg

Basically I'd like to get feedback to know if these circuits need to be modified or if they are over engineered for the purpose of device control and flexibility.

Thanks !
 

Ian0

Joined Aug 7, 2020
6,983
Mainly good, but the 1k resistors spoil it. No point in using a 4A driver, then limiting its current to 10mA!
The gate drive resistors should be in the region of 10Ω.
However, if you are not using PWM to dim the LEDs or speed-control the motor, it is questionable if a low-side driver is required at all with a logic-level MOSFET. It is a good idea in that it protects the microcontroller from any nasty voltage around the MOSFET and probably will protect the microcontroller if the MOSFET fails.
Be careful that you don't exceed the maximum gate voltage (which must be elsewhere on the datasheet)
 
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