How to measure output frequency of this IC ( IR2153) ?

Thread Starter

LETITROLL

Joined Oct 9, 2013
218
Hi everybody here .

I am trying to measure the output frequency of tthe IR2153 H-bridge gate driver IC based on the circuit attached bellow, but i don't know how to measure it with the DMM , when i place the black prob on VS and COM , and red on eather output i don't get any reading .

The configuration am using is a 37 Kohm resistor with a 2.2 nF capacitor witch is supposed to give about 12 Khz .

Please take a look at the picture attached bellow for a clear idea .
 

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tindel

Joined Sep 16, 2012
936
Is your meter on DC setting? At that frequency the DC filter may filter out the voltage. Does your meter have a frequency setting?

If not maybe putting it on AC couple will provide some clues... What is your output voltage?
 

Thread Starter

LETITROLL

Joined Oct 9, 2013
218
Is your meter on DC setting? At that frequency the DC filter may filter out the voltage. Does your meter have a frequency setting?

If not maybe putting it on AC couple will provide some clues... What is your output voltage?
I appreciate your replay tindel .

Ok . I am using a simple DMM with frequency ( no settings available) , i don't have DC on frequency nor AC .

I have set the frequency at 12 KHZ using 36 kohm resistor and 2.2 nF cap according to this calculus : F=1/RC

Here is a picture of the IC internal elements :

 

Alec_t

Joined Sep 17, 2013
14,280
How do you know the IC is actually generating a frequency?
Can you post a schematic showing everything connected to the IC?
 

Thread Starter

LETITROLL

Joined Oct 9, 2013
218
This is the way i wired the IC , i have connected pins 1 and 8 to 12 Vdc , 4 and 6 to GND , 2 and 3 for the oscillator's frequency , and 7 /5 for the outputs.


 

Alec_t

Joined Sep 17, 2013
14,280
Are you sure your '12V' is exactly that? According to its datasheet the IC has a Rising VCC undervoltage lockout threshold which is typically 11V but may be as much as 12V. If the lockout is active then the IC won't generate a frequency at pin 5 or 7.
 

Thread Starter

LETITROLL

Joined Oct 9, 2013
218
Hi again .

I have decided to place the IC on the original PSU , removing the transformer and using the lamp fuse trick .

What i got is a 90 Vac drop on the lamp and the mosfets are getting pretty warm .

How much voltage should the lamp be dropping when everything is fine ?
 

Thread Starter

LETITROLL

Joined Oct 9, 2013
218
I can't answer your question without seeing a schematic of the complete system which you now have.
Hi Alec .

Am really sorry i don't have a schematic ,but after more research , i found that this PSU is working with a 24 Vac and not 230 v .

Right now the IC is fed by approximately 14-15 Vdc , but the outputs are different , Lo is 9 Khz, Ho is 14.5 Khz .

As far as i know the two mosfets should be driven by the same frequency ?
 
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