Hello Everybody

I am trying to develop a drive for BLDC motors using AT90PWM3B

Mosfet drivers i am using are IRF2101

initially everything seems fine and motor runs OK

But i have observed after some time the drivers are getting heated up and start showing erratic behavior and eventually burning up.

Can anyone help me on this?

Regards,
Kapil

I have used IRF2110 to do the same the are the prefect choice for it. I think its same for 2101 also. Please make note of the following as they can be a reason for your problem:

* Not enough of float voltage is being supplied to the mosfet gate(check the boot strapping configuration)

* the mosfets have high RdsON resistance, Power consumed by the mosfet increases exponentially with current. try IRF3205 they have an RdsON of just 0.008Ohm and Id of about 110A! Most mosfets if operating on high current need a heat-sink.

* could be a shoot through(both gates of one side open at the same time)

* Apply current limit resistance before the gate about 330E should do it.

5: not enough time is being given to the Cds and Cgs and Cgd capacitance to charge hence they are getting short. first try to use a regulated DC source for checking the design.

Tell me about your progress

Happy to help

Regards
Asim Siddiqui

do not use IR drivers !!!
do not use ANY gate driver with flip-flop for upper device.
try not to use bootstrap, use regular dc/dc with transformer

You can use 3-phase MOSFET driver as HIP4086 for example instead of separate drivers for each power MOSFET as well.
But your overheating problem can be related to low inductance of BLDC motor - especially for iron less ones. Than higher PWM frequency or external chokes can help you to overcome the problem. BTW how you measure a motor current?

With respect to the experience and knowledge of Adam, i still highly recommend mosfet drivers with correct configuration for efficient switching of Mosfets in the H bridge. we require float voltage to keep the mosfets on and in saturation region which is easily possible with IR drivers, HIP from Intersil is also a good choice giving a full bridge driver in 1 ic with less external components, but it may have a constrain with the maximum float voltage, which again depends on the voltage across the source and drain.

Kapil,
I think it would be useful to provide some details about your bridge (current, voltage, frequency) and driver (bootstrap capacitance, gate resistor,...).

"we require float voltage to keep the mosfets on and in saturation region which is easily possible with IR drivers"
OK - turning ON FET with 10V is one thing...
Gate driver overheating and exploding is another thing.

I'm trying to help...

Ok, if you don't want to listen - just answer this question:

"why IR is having MANY new releases of almost same IC?"
2101, 2110, 2135, ....2183 now


anyway, you trying to use 250mA driver to drive big, hi capacitance FET.
What is your PWM freq?
Did you do ANY calculations for gate charge , power dissipation, power required to drive gate...???
See - in electronics some math is needed sometimes, just connecting "point A to point B" doesn't work.

Or just keep trying to use your 2101 chip - this way we have job security in US...

I consider my self as a person with low IQ. But as far as i could interpret Kapils problem, He is not using any mosfet Drivers. His mosfets are overheating and burning and NOT the drivers as Adam said:
"Gate driver overheating and exploding is another thing. "

More so i would second Sandro, that kapil should provide us with more details about the design boundary conditions with such as maximum intended current, voltage, frequency, bootstrap capacitance, gate resistor,..etc. for the design.

"after some time the drivers are getting heated up and start showing erratic behavior and eventually burning up"

1.i think for each column of Mosfet or IGBT you should put a electrolyte capacitor
in order to have strang Drive and Driver you should use IGBT and IGBT Dirver