[SOLVED] IR2110 HO always High

[tux1]

Hi
I tried using IR2110 for half bridge configuration; but high side output is always high around 10.5V. The input frequency is 15kHz and I'm using 47uF capacitor as bootstrap. Tried the same using 10uF bootstrap. LO is fine. I'm just checking the IR2110 without the MOSFETs so I've connected Vs to ground.

 

[Electro nS]

Hi
I tried using IR2110 for half bridge configuration; but high side output is always high around 10.5V. The input frequency is 15kHz and I'm using 47uF capacitor as bootstrap. Tried the same using 10uF bootstrap. LO is fine. I'm just checking the IR2110 without the MOSFETs so I've connected Vs to ground.

thats a false high ! , if your supply is 24v HO (high level ) is 36v , if your supply is 12v HO will be 24v , but you will never see that unless u are switching and by oscilloscope . and without mosfets it will never work , you have to have the whole circuit , !
if you connect vs to gnd then the high side become similar to the low side no , bootstraping in this case use all capacitors =1uF (non polarizied) .
post schematic if you need more help
regards

 

[tux1]

Hi Electro nS
Thanks for the reply!
I was using 12V supply and in that case as you said the output of HO should be 24V. I've progressed a little to observe the switching using Oscilloscope. But the voltage level what i observe is not greater than 11V, and that's with Vs ground.
Now when i connect it to the Mosfets, what i observe is a distorted pulse at the gate and also the pwm from the controller is also distorted.
The mosfets get hot as there is less than 8V at the gate is my observation.
I always have issues associated when using pwm which i could not sort out.
Included my schematic

 

[Electro nS]

try this out , use a big decoupling capacitor (1000uF 35v minimum) across the mosfets ( from Vbat to GND ) , the mosfets gets hot because they are not switched correctly and they are working in linear region , by the way what is the value of the gate resistor it should be from 10ohm to 100ohm ?
where are u testing breadboard or pcb , because of inductance and bad wiring ?
try this link for a better schematic and more explanation : https://tahmidmc.blogspot.com/2013/01/using-high-low-side-driver-ir2110-with.html
hope this helps

 

[Electronics_chaitanya]

hello



Keep these thing in mind..... never try IR2110 without MOSFETS .bcos it will not give proper HO pulses w/o FETS.





-regards

 

[tux1]

Hi

Thanks for the replies and sorry the delay.

I have a created a PCB with complete connection(including MOSFETs). I was referring

https://tahmidmc.blogspot.in/2013/01/using-high-low-side-driver-ir2110-with.html

I have a gate resistor of 10ohm

The PCB seems to work sometimes. very rare. And blows up mostly. I'm sure I'm missing something, which right now is invisible to my eyes :sad:

Regards

 

[Electro nS]

give signal for hin inverted to whats on Lin and donot go for 100% duty cycle . your bootstrap wont handle that

 

[tux1]

Hi Electro nS

Thanks Again!!!

I am generating pwm for about 15kHz using uC and that pwm along with an inverted pwm from a not gate is used.
I am not going for 100% duty cycle. Its just 40% or 50%.

Regards

 

[Electro nS]

Hi Electro nS

Thanks Again!!!

I am generating pwm for about 15kHz using uC and that pwm along with an inverted pwm from a not gate is used.
I am not going for 100% duty cycle. Its just 40% or 50%.

Regards

so did it work ??? this setup should be working , i forgot to mention something about the delay between high side and low side signal , what is happening is that it works sometimes , but when the higher mosfet is being turned off and the lower mosfet is turning on , in this stage ,both mosfets are on on the same time causing a short through from VCC to GND .

solution1: make somekind of delay between Hin and Lin , using RC
check the image in the buttom of this page :
https://electronics.stackexchange.c...s-of-a-mosfet-driver-with-a-single-pwm-signal

solution2: or better use IR2184(internal 500ns delay) or IR21844 (external adjustable delay up to 2us)

General caution: and in all case use a fast fuze ( for example "Blade" like used in most cars these are fast acting) in series with VCC , so if shortcircuit occur the fuze blow and the mosfets stay alive


HOPE THIS HELPS ))))))

 

[tux1]

Hi Electro nS

Thank you for your response.

Solution1: This is an incredible Idea, just have to check that (will let you know once I'm okay with that)

Solution2: Is also good if dead time really matters in this case.

Well, I'm using a fuze to save my Mosfet's life. (General Caution)

That was really helpful Electro nS

Thanks again:smile:

 

[Electronics_chaitanya]

ya there is probability of cross conduction........check out waveforms on scope .... bcos if we make small mistake in programming as u know .......MOSFET burns ....... actually I also tried on IR2110 and failed about 15-20 times then I reffer thamid blog ......now I am using 2110 if with about 500vDC and really it rocks.....



in short try and try you will success but don't forget to use your mind