I want select a suitable driver for a MOSFET (IRLZ44n) to control 12V DC motor using Arduino's PWM. I found this application note that provides guidance to select mosfet driver. According to this application note, peak drive current required by MOSFET is,
Ig = Qg/t
According to datasheet, Qg~30nc (@ Vgs = 5V and Vds = 12V). Let charge time t = 60ns.
Ig = 30/60 = 0.5A

Using this value, I looked for drivers that can provide output current of 0.5A at 5V. But, when I looked through driver datasheet, I found that it can charge or discharge 1000pF ( or 1 nF) in 30ns. I used this value to calculate charge/discharge time as follows,
Input Capacitance, C = Qg/Vg,
C = 30/5 = 6nF

charge/discharge time, t = 6 * 30ns = 180ns

I am confused now as I was looking to select drivers based on peak current value that was found at the start. What am I missing?

Also, Mosfet drivers have different output configuration (like Single, Dual, Inverting, Non - Inverting etc). Can somebody please provide a simple explaination of the differences between these configuration and how it affects selection?

 

I am confused now as I was looking to select drivers based on peak current value that was found at the start. What am I missing?

I think what you're missing is the fact that given the low frequency (≈500 Hz, if I remember correctly) of the Arduino's PWM output, just about any of the commercially available MOSFET driver chips will serve your application adequately; you don't need to undertake detailed analysis to find the "right" one.

Also, Mosfet drivers have different output configuration (like Single, Dual, Inverting, Non - Inverting etc). Can somebody please provide a simple explaination of the differences between these configuration and how it affects selection?

Single = there is only one driver in the IC
Dual = there are two separate drivers in the IC
Inverting = driver output is LOW when its input is HIGH
Non-inverting = driver output is HIGH when its input is HIGH

 

You are really concerned about the power dissipation during the switching time.
Generally you want that time to be less than one percent of the switching period to minimize this dissipation.
Thus at a low PWM frequency (say the 500Hz that OBW0549 mentioned), 1% of the period is 20μs, so if you keep the switching time below 1μs, there should be no dissipation problem.
You don't need 60ns switching time.
Thus just about any driver should work for you as OBW0549 noted.

You can make a rough estimate of the switching power loss by multiplying the supply voltage times the maximum current times the switching time (transition) times the switching frequency (V × I × Tsw × F).

 

I gather that you are committed to 500hz using Arduino? if so you may get switching noise, the general guide line is 4.5Khz - 5 Khz min. for DC motor control for quieter operation.
Max.

 

Non-inverting = driver output is HIGH when its input is HIGH

I looked at

Single = there is only one driver in the IC
Dual = there are two separate drivers in the IC
Inverting = driver output is LOW when its input is HIGH
Non-inverting = driver output is HIGH when its input is HIGH

One of the things I want to do is use two Dc motors for my project. My plan is to use separate driver for each mosfet. Can a single mosfet driver like Dual non inverting control two dc motors? The Dc motors will be driven in single direction

Thus at a low PWM frequency (say the 500Hz that OBW0549 mentioned), 1% of the period is 20μs, so if you keep the switching time below 1μs, there should be no dissipation problem.
You don't need 60ns switching time.
Thus just about any driver should work for you as OBW0549 noted.

One of the things I failed to mention is that the switching frequency is atleast 10KHz. Does this still mean any driver would work for me or do i have to look for specific drivers that will operate at higher frequencies?

I gather that you are committed to 500hz using Arduino? if so you may get switching noise, the general guide line is 4.5Khz - 5 Khz min. for DC motor control for quieter operation.
Max.

Thank You Max. I failed to mention in this post that my switching frequency is atleast 10KHz.

 

One of the things I want to do is use two Dc motors for my project. My plan is to use separate driver for each mosfet. Can a single mosfet driver like Dual non inverting control two dc motors? The Dc motors will be driven in single direction

If you've got two motors and each motor needs one MOSFET and one MOSFET gate driver circuit, then a dual driver IC with two driver circuits would be able to control two motors.

One of the things I failed to mention is that the switching frequency is atleast 10KHz. Does this still mean any driver would work for me or do i have to look for specific drivers that will operate at higher frequencies?

Even at 10 kHz, just about any available gate driver chip should work fine. 10 kHz is not a very high frequency.

 

If you've got two motors and each motor needs one MOSFET and one MOSFET gate driver circuit, then a dual driver IC with two driver circuits would be able to control two motors.

Alright, 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 TC4427A to drive the mosfets IPP45N06S04L-08. The non inverting characteristic of the driver will switch on the mosfet when Arduino's PWM signal is high. Am I thinking correctly?

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?

 

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 usually also use a ultra fast diode across the 10Ω gate resistor, anode to gate.
Those FETs show 16v gate to source.
Max.

 

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?

You don't have to restrict it to 10V. That is the Vgs to ensure the FET turns on fully. As Max noted, the maximum Vgs allowed is 16V.

 

I usually also use a ultra fast diode across the 10Ω gate resistor, anode to gate.
Those FETs show 16v gate to source.
Max.

I did not get your point of using a diode across resistor. Could you please clarify a bit on that. Also, where is anode in the driver?

You don't have to restrict it to 10V. That is the Vgs to ensure the FET turns on fully. As Max noted, the maximum Vgs allowed is 16V.

Yeah you are right. I will let the Vgs be at 12V as the conduction losses are lower.

 

Alright, 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,

No, it is incorrect: your diagram shows the INA input of the driver chip shorted to the GND pin.

With this arrangement can I control the motors simultaneously?

For the last time, YES!!!!

Can this driver provide the same voltage and current required to switch on both the mosfets?

Read the driver and MOSFET data sheets and decide for yourself. My answer: YES.

 

I did not get your point of using a diode across resistor. Could you please clarify a bit on that. Also, where is anode in the driver?

.

A little more on it here, although it is generally aimed at the IR2110 but applies in other cases (anode of the rectifier).
Tahmid's blog: Using the high-low side driver IR2110 - explanation and plenty of example circuits
Max.