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MOSFET (Si/SiC) Forum Discussions

Harold
Level 1
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Level 1
I'm not sure if I can drive a 24V (0.5A) dc motor with the following circuits?
5407.attach

I fear that there will be burned too much power in the transistor when the supply is 24V (I will become super hot).

Here is a link to the datasheet for the IRLZ44N
1 Solution
Abhilash_P
Moderator
Moderator 25 likes received 250 replies posted 250 sign-ins
Moderator
Hi,

The following are the conditions that has to be taken into account while driving a DC motor using MOSFET,

1) The power MOSFET has to be selected to handle atleast the power supply voltage and the drain current needed by the motor.
2) The VDS (drain to source voltage) of the MOSFET should be atleast 20% higher than the supply voltage.
3) To support high torque, a high margin on drain current has to be considered.

The VDS of the selected mosfet is 54V, which is 20% higher than the source voltage 24V.
The maximum current it can handle is 47A,

Please share the spice model of the MOSFET if available. We can simulate the circuit for the given condition
In the meantime i will use a similar MOSFET from infineon and simulate the given circuit for temperature rise.



Regards,
Abhilash P

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2 Replies
Abhilash_P
Moderator
Moderator 25 likes received 250 replies posted 250 sign-ins
Moderator
Hi,

The following are the conditions that has to be taken into account while driving a DC motor using MOSFET,

1) The power MOSFET has to be selected to handle atleast the power supply voltage and the drain current needed by the motor.
2) The VDS (drain to source voltage) of the MOSFET should be atleast 20% higher than the supply voltage.
3) To support high torque, a high margin on drain current has to be considered.

The VDS of the selected mosfet is 54V, which is 20% higher than the source voltage 24V.
The maximum current it can handle is 47A,

Please share the spice model of the MOSFET if available. We can simulate the circuit for the given condition
In the meantime i will use a similar MOSFET from infineon and simulate the given circuit for temperature rise.



Regards,
Abhilash P
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roewetom
Employee
5 replies posted First solution authored First like received
Employee

Hi Harold,

additional to what Abhilash answered:

I guess you consider this one: https://www.infineon.com/cms/en/product/power/mosfet/n-channel/irlz44n/

On that page you find also the simulation models (https://www.infineon.com/cms/en/product/power/mosfet/n-channel/irlz44n/#!simulation).

I'm pretty sure that it can do the job. But the main thing is if your MCU can drive the 48nC gate charge @5V VGS.

I would also recommend that you use a gate resistance of 10 - 20 Ohms to limit the current into the gate to 250 - 500mA. If the current exceeds what the MCU can drive probably this driver can support to do the job: https://www.infineon.com/dgdl/Infineon-1EDN7550U-DataSheet-v02_02-EN.pdf?fileId=5546d462700c0ae60170...

With this one you also could use the MOSFET as high-side switch and the motor below.  

Let us know how your project goes on.

Best regards

Tom

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