IR2101 gets damaged

Thread Starter

iqram

Joined Aug 24, 2019
6
Hi,

I am using IR2101 to drive DC motor. I am using only one IR2101 to run DC motor in one direction. I am keeping lower N-channel FET (both FETs are IRF540N) and using PWM for High side FET.

I have only 10E resister from HO and LO to each Gate. The IR2101 goes bad after few seconds. What can be the reason?

Do I have to keep Diode across gate resistor to protect IR2101?

Please help.!

Thanks.!
Iqram
 

Alec_t

Joined Sep 17, 2013
14,280
Welcome to AAC!
If you post a schematic, with all components labelled, it might help us to identify the problem.
 

Thread Starter

iqram

Joined Aug 24, 2019
6
Thank you Alec_t, MaxHeadRoom for looking into my problem.

Please find attached schematic.

In fact I want to run BLDC motor with 3 such circuits. I could not run, so thought of understanding that using one DC motor. But, I lost 4 IR2101 already. I was searching about reason and found one post https://forum.allaboutcircuits.com/threads/ir2101-problem-with-300vdc.96901/ . It is mentioning to put Diode on Gate. I want to know how is that Diode kept.

Please suggest your thoughts. I am not at all expert in Analog or MOSFETs. This is the first time I am trying.

Thanks.!
Iqram
 

Attachments

Thread Starter

iqram

Joined Aug 24, 2019
6
I forgot to mention that, HIN input is getting PWM signal from Microcontroller and LIN is set to 1 from Microcontroller.

Thanks.!
Iqram
 

LesJones

Joined Jan 8, 2017
4,174
I suspect the way you are using the driver will not work correctly as the bootstrap circuit that generates the positive voltage above the 24 volts supply (Required to drive the gate of the upper mosfet positive with respect to the +24 volt rail.) is not working. The bootstrap circuit depends on seeing about a 24 volt square wave on the right hand end of capacitor C2. So even when the top mosfet it not conducting the motor still rotating and acting as a generator will keep the right hand end of C2 at quite a high voltage so the amplitude of the square wave will be too low to generate the bootstrap voltage. IF the circuit was working as the manufacturer intended then I would expect pin 8 of the IR2101 to be close to +48 volts with respect to the ground point on your circuit. I suggest that you test to see if this is the case.

Les.
 

Alec_t

Joined Sep 17, 2013
14,280
Have a read of this. It may explain the IR2101 damage.

Edit: As for the bootstrap operation, could you just swap over the Hin and Lin signals and drive the right-hand end of C2 from Q2 drain instead of Q1 source? The Vs pin of the IC would then need a clamping diode to the +24V supply.
 
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Thread Starter

iqram

Joined Aug 24, 2019
6
@Alec_t I think, my circuit is also facing same issue as mentioned in the article you referred. I have attached schematic with additional Diode. I think this should solve my problem (I am still not sure).
In the regular Half Bridge, the Diode of lower MOSFET should work same as this new diode.

@DickCappels The motor is 24V and max current shows 8A. I am using 500Hz commutation frequency and started operating at 10 to 20 % of duty cycle. I have not measured the current during operation.

Please advice.

Thanks.!
Iqram
 

Attachments

Alec_t

Joined Sep 17, 2013
14,280
I think, if I add D2 as shown in attached snapshot, it will solve my problem.
D2 needs to be a Schottky type, so that its forward voltage is less than that of the FET's body diode, since (from my understanding of the App Note) the body diode can be part of the cause of the problem.
Edit: I've just noticed you're missing a freewheeling diode across the motor. Without that, large voltage spikes will appear on the Vs pin. That's probably what fried your ICs.
 
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LesJones

Joined Jan 8, 2017
4,174
I don't see that the diode D2 will solve the bootstrap voltage problem. I think you need to connect a diode between Q1 source and the motor so that the voltage generated by the motor while spinning is not fed back to the source of Q1 You will also need to connect a load resistor between Q1 source and Q2 drain. As Alec said you should also have a freewheeling diode across the motor to prevent the high voltage spike that is generated by the inductance of the motor when the current through the motor is switched off. I don't see why you can't just use the lower mosfet for PWM and connect the top end of the motor to 24 volts. If you want to stop the motor just set the PWM duty cycle to zero.The lower driver in the IR2101 does not need the bootstrapping to work.

Les.
 
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shortbus

Joined Sep 30, 2009
10,045
In fact I want to run BLDC motor with 3 such circuits. I could not run, so thought of understanding that using one DC motor.
Think you will find that A BLDC doesn't use three DC motor circuits to drive them. The BLDC has two of the three coils on at one time not one. To get a better understanding of what you trying to do, download the PDF from here - https://www.onsemi.com/products/power-management/motor-drivers/motor-drivers-brushless/mc33035
Explains BLDC motor divers and the wave forms needed pretty good.
 

Thread Starter

iqram

Joined Aug 24, 2019
6
Thank you all for looking into the problem I am facing. I rally appreciate your help and suggestions.

I started with BLDC by looking at https://simple-circuit.com/arduino-cd-rom-brushless-motor-control/ . I made same circuit on General Purpose Board and used 24V on MOSFET's Drain while 12V to IR2101 VCC. This blew few MOSFETs of this circuit. I replaced those faulty FETs, still I could not rotate BLDC motor. I gave 15V to IR2101 after I replaced FETs, but my LM7815 was getting corrupted. That circuit is no more alive looks like.

I thought of understanding the concept by using one Half bridge IC and two MOSFETs with DC motor (similar way as two winding come in between two FETs ). I ran into another problem. https://www.microchip.com/DevelopmentTools/ProductDetails/PartNO/DM183021 also shows similar circuit without any protection around IR2101.

I will again try with the circuit shown this Microchip's article and try running BLDC motor. I am still afraid, IR2101 will go bad :(.

I will update you guys with my progress. I am little slow, but will definitely update you guys.

I will have to go through https://www.onsemi.com/products/power-management/motor-drivers/motor-drivers-brushless/mc33035 yet.

Thanks.!
Iqram
 

BobaMosfet

Joined Jul 1, 2009
2,110
Thank you Alec_t, MaxHeadRoom for looking into my problem.

Please find attached schematic.

In fact I want to run BLDC motor with 3 such circuits. I could not run, so thought of understanding that using one DC motor. But, I lost 4 IR2101 already. I was searching about reason and found one post https://forum.allaboutcircuits.com/threads/ir2101-problem-with-300vdc.96901/ . It is mentioning to put Diode on Gate. I want to know how is that Diode kept.

Please suggest your thoughts. I am not at all expert in Analog or MOSFETs. This is the first time I am trying.

Thanks.!
Iqram

I looked at your schematic. Why don't you have a snubber diode across your motor? It's an inductor, and without it you have no protection for your FETs.
 
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