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

Discussion in 'General Electronics Chat' started by LETITROLL, Dec 25, 2014.

  1. LETITROLL

    Thread Starter Member

    Oct 9, 2013
    218
    2
    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 .
     
  2. tindel

    Active Member

    Sep 16, 2012
    568
    193
    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?
     
  3. LETITROLL

    Thread Starter Member

    Oct 9, 2013
    218
    2
    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 :

    [​IMG]
     
  4. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    How do you know the IC is actually generating a frequency?
    Can you post a schematic showing everything connected to the IC?
     
  5. LETITROLL

    Thread Starter Member

    Oct 9, 2013
    218
    2
    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.


    [​IMG]
     
  6. LETITROLL

    Thread Starter Member

    Oct 9, 2013
    218
    2
    any ideas Alec T ?
     
  7. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    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.
     
  8. LETITROLL

    Thread Starter Member

    Oct 9, 2013
    218
    2
    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 ?
     
  9. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    I can't answer your question without seeing a schematic of the complete system which you now have.
     
  10. LETITROLL

    Thread Starter Member

    Oct 9, 2013
    218
    2
    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 ?
     
  11. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Indeed they should. So it seems either the IC is duff or your meter is playing up.
     
  12. LETITROLL

    Thread Starter Member

    Oct 9, 2013
    218
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    Thanks man , i appreciate your time .
     
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