how to test an op amp 741

[sukanya]

hello
i am building an IC tester. It should test OP AMP 741.How can i do the test for proper fuctioning of above said IC. I am using PIc for testing of various logic ics as of now.
thank you

 

[Nigel Goodwin]

hello
i am building an IC tester. It should test OP AMP 741.How can i do the test for proper fuctioning of above said IC. I am using PIc for testing of various logic ics as of now.
thank you

I would suggest you have a look at which will help you to understand the 741 (and opamps in general).

You will probably have to decide what you want to test, and how you intend to do it - a simple 'GO/NO GO' test would probably be pretty easy to do, otherwise testing an analogue device with a digital one could be tricky!.

For a simple 'GO/NO GO' test you could wire a 741 as an oscillator, and use the PIC to measure the frequency - if it's within your permitted range it's OK, if it's outside the permitted range it fails.

 

[Johnson777717]

I read in a book called "Making your own test equiment" which has an IC tester. The simple basis of testing is GO-NO GO as Nigel explained above. The circuit uses a bunch of 2n3904 transistors and LED's to form numerous logic probes (One for each pin). Thus, when a pin is high, the LED lights up for that specific pin.

With that said, the circuit that I am speaking of basically tests whether the IC is functioning, and wouldn't give you any more information as to what the frequencies are, and how the pins work together.

I can post a schematic if this is what you're looking for.

 

[DemonRising]

i've noticed ic testers fail in at least 2 ways.

1) they dont load the chip. so the ic will pass unloaded and fail when loaded in circuit. i've tested bad ic's in a tester and they have passed, put them back in circuit and they fail. replace the suspect ic then the equipment worked.

2) they don't check probogation delay time. i've only seen this once or twice, but i checked this bad ic in a tester and it passed, put it back in circuit and it failed. replace the suspect ic and the equipment worked

while ic testers can be useful in testing a dead ic, the 2 issues above have destroyed my confidence in them.

i just wanted to point this out. i'd hate to see you chasing your tail putting bad ic's back into circuit.

 

[Ravi]

Dear Johnson

I also read the same book.What is your idea of LED O-scope given in that book. Is it a workable ckt?Appreciate your views.