Problem with IR2110 to drive an H-Bridge

Thread Starter

jean120

Joined Jan 24, 2016
75
Hello everybody,I have a problem which made me to spend two weeks trying to find the error but not find,please can you help me to handle??

I am making an H-bridge which is controlled by the IR2110(2) but I am not getting the HO (output high) on all the driver(IR2110) but the LO are there.
With oscilloscope in order to obtain the HO ,I have to use the second probe and connect its ground to the ground of the circuit.
My circuit configuration is like the one of Tahmid blog on this link http://tahmidmc.blogspot.com/2013/01/using-high-low-side-driver-ir2110-with.html .
Please help me to handle this problem.
 

Thread Starter

jean120

Joined Jan 24, 2016
75
Is the switching frequency causing this problem I have?I am using the PWM freq of 16KHZ.
I am not obtaining the High side output,only the low side output is visualized on the oscilloscope for the two IR2110 I used.

Please help.

Thx
 

Alec_t

Joined Sep 17, 2013
14,280
I am not obtaining the High side output
What is the measured voltage on the HO pin of the IC?
What load do you have connected across the bridge?
What is your Vcc voltage (if it's too low the under-voltage protection in the chip will kick in and prevent HO going high)?
 
Last edited:

Thread Starter

jean120

Joined Jan 24, 2016
75
hello,no load connected yet on the H-bridge.
On the HO,the output voltage is zero.The VCC is +12V DC and Vss is +5V dc
Please help
 

shortbus

Joined Sep 30, 2009
10,045
hello,no load connected yet on the H-bridge.
With oscilloscope in order to obtain the HO ,I have to use the second probe and connect its ground to the ground of the circuit.
Your problem may lie in those two quotes. For the bootstrap to work it must go to ground at some point in the cycle. With no load ,a motor or even a resistor or light bulb, there is no path to ground to charge the boot capacitor.

Are you sure the boot circuit diode is inserted in the correct direction?
 

MaxHeadRoom

Joined Jul 18, 2013
28,617
My HIN & LIN are both opto isolated so this enables using 15v for both VCC & VDD if you wish, which is what I use generally.
Max.
 

Thread Starter

jean120

Joined Jan 24, 2016
75
Your problem may lie in those two quotes. For the bootstrap to work it must go to ground at some point in the cycle. With no load ,a motor or even a resistor or light bulb, there is no path to ground to charge the boot capacitor.

Are you sure the boot circuit diode is inserted in the correct direction?
Sir,You want to mean that for getting the HO,I have to connect the load?When measuring the voltage Gnd to pin 5 and Gnd to pin 6(positive side of bootstarp) I find the same voltage.
 

Thread Starter

jean120

Joined Jan 24, 2016
75
My HIN & LIN are both opto isolated so this enables using 15v for both VCC & VDD if you wish, which is what I use generally.
Max.
Sir,will the connection of VCC&VDD to +15V solve the problem so that I can measure the HO and get it on the oscilloscope?
Best Regards,
 

Thread Starter

jean120

Joined Jan 24, 2016
75
What is the measured voltage on the HO pin of the IC?
What load do you have connected across the bridge?
What is your Vcc voltage (if it's too low the under-voltage protection in the chip will kick in and prevent HO going high)?
The Vcc is +12V and no load connected on the circuit.
 

Alec_t

Joined Sep 17, 2013
14,280
Which one of Tahmid's blog circuits have you built, and is it exactly as he shows?
Make sure you have a load (e.g. a ~1k resistor) connected when you test the circuit.
The Vs pin needs to be pulled repeatedly high and low for the bootstrap to work. Without that action HO will not pulse high.
 

MaxHeadRoom

Joined Jul 18, 2013
28,617
I think you mean the Vsource has to be low, In my case I switch the lower fet on continuously (Lin) and use the PWM into upper input (Hin).
This conforms to the typical Microchip CCP PWM output.
Max.
 

Thread Starter

jean120

Joined Jan 24, 2016
75
Which one of Tahmid's blog circuits have you built, and is it exactly as he shows?
Make sure you have a load (e.g. a ~1k resistor) connected when you test the circuit.
The Vs pin needs to be pulled repeatedly high and low for the bootstrap to work. Without that action HO will not pulse high.
I add the load and test again hope I get the good output.

Thank you!!
 

Thread Starter

jean120

Joined Jan 24, 2016
75
Hello,as Alec_t has advised I added a load on my circuit but I get no output,still the HO is not obtained;I ma measuring with the oscilloscope and digital voltmeter.

Please help!!

Thx
 
Top