How to check if my Op-Amp is damaged?

Submitted by Violet on Thu, 08/16/2018 - 11:48

Hi,

The circuit that I am working on has a hand full of comparators, amplifiers and buffers. For which we are using the LM741 and LM358 Op-Amp. 

Since we are just testing the design many times we doubt that the Op-Amp has been damaged (stopped working) whenever we don't get the desired results.

Is there a way to test if the Op-Amps are functioning properly?  I do not want to throw away the IC before making sure its damaged.

Also I do not have much test instruments with me, I only have a multimeter and a RPS.

Thanks

Violet

Yes dear, you can use a multimeter to check if you op-amp is working properly. I have been using the LM741 and LM358 for donkeys ages now and I always use the below method to check if these guys are working as they are supposed to.

For this test it is recommended for you to have a dual power source, but it is not mandatory.

  1. Power the Op-Amp through Vcc and -Vcc pin. For simplicity lets assume Vcc=V and -Vcc=0V (ground)
  2. Connect both the input terminals (inverting and non-inverting terminals) to ground. Now if you measure the output voltage it should be 0V
  3. Now, connect the non-inverting terminal alone to Vcc(5V). The output should now be 5V
  4. Similarly check the same for inverting Pin. The output should be 0V when connected to Vcc

​Simply put we are checking the op-amp in voltage follower a.k.a voltage buffer configuration.

If all these conditions are satisfied then you Op-amp is working properly. 

Have fun. Enjoy electronics 

  Joined August 17, 2018      14
Friday at 11:08 AM

Your explanation is good.  For people like me, if you can  explain the above with reference to pin nos. it will be more useful, becuase  we c'not understand what is 'inverting' / ,'not inverting' terminals etc. etc. I am a non technical person, but interested in experimenting in  electronics.  Thank you. VG KRISHNA from India. 

  Joined November 05, 2019      1
Tuesday at 08:04 AM

As expected all the Op-Amps were working like a charm in voltage follower mode. I also tested them in comparator mode just to make sure they were good. So then I started tweaking my circuit and found there was a lame mistake in my connection.

Rectified it and now everything works fine. Thanks for saving my Op-Amps from being dumped 

  Joined August 16, 2018      42
Thursday at 11:31 AM

Hi, just followed ur instructions to test op-amp, what if i connect op-amp on inverting and get 1.9v out, does that mean the op-amp is faulty. how does a Lm358 or MC 1458p go faulty when it has never worked before and all it requires is straight 5/9V with no resistors even to test to inverting and non inv. Boggles my mind.

  Joined March 27, 2021      1
Saturday at 03:39 PM

Here's a thought. With the circuit wired up and running-use IC ssockets. remove one of the working good IC's and putin each IC that is to be tested.

  Joined October 22, 2021      7
Friday at 08:53 PM

Yeah that is effective.

  Joined February 12, 2018      696
Monday at 02:11 PM