I am new to the concept of electronic design and require help with my project.
I want to use two N-channel Mosfets to control two 12V DC motors with Arduino's PWM. The PWM frequency will be atleast 10KHz and motors will be running in single direction.
I did some research on how to use a single mosfet driver to run two motors and this is best I have come up with and please tell me if the following circuit is correct,
As my circuit is low side driver, I decided to use Microchip's TC4427A to drive the mosfets IPP45N06S4L-08. TC4427A is a dual non-inverting driver with peak output current of 1.5A and input supply voltage operating range 4.5V to 18V. The non inverting characteristic of the driver will switch on the mosfet when Arduino's PWM signal is high. Am I thinking correctly? (P.S. Since I could not add more than two links, I gave brief description of the driver)
With this arrangement can I control the motors simultaneously? Can this driver provide the same voltage and current required to switch on both the mosfets?
What is gate voltage provided by the driver? Is it same as VDD (in this case 12V)? If yes, what are the changes I have to make to restrict the supply to the gate to 10V?
I have provided 10Ω resistors between gate and driver output? Is this necessary as I read that it reduces the EMI or Oscillations (I am not sure as I do not understand this concept clearly) and improves PWM?
I have provided capacitors between GND and VDD of the driver? Is the arrangement correct? What is the method to calculate its capacitance?
Are there any drawbacks with this circuit? Do i need to be aware of any underlying issues that may blow up the mosfet or driver?
Best Answer
Yes, you can control the two motors individually. Your schematic is missing a dot- generally you should avoid lines crossing as shown- offset one of the wires.
You could add a 10V regulator to reduce the gate drive to 10V but there is absolutely no reason to do so- the gates can handle 16V and 12V is better than 10V for reducing conduction losses.
The series resistors on the gates are a good idea- they can help reduce ringing and overshoot/undershoot that could damage the gate driver and limit the current if it does occur.
The bypass capacitor on the gate driver can be made large enough that the gate charge on the MOSFETs would not change the voltage much. A ceramic X7R cap in the 1uF range is usually good.