IC chip identification when the part number is worn off: possible or not?

[211]

If the writing on the top of an IC chip is worn off or no longer readable is there a way to tell what type of chip it is without a schematic?

I assume probably not...

 

[carbonzit]

Maybe, maybe not. # of pins? Likely digital or linear? If it's in circuit, what is its likely function?

Power pins are somewhat standard (7 & 14 for 14-pin DIPs, for example), so you might be able to (carefully) apply power and see if you can "ring out" the chip. This might work for relatively simple functions (AND, OR, NAND, etc.); not very likely to work for more complex functions. If it's an op amp, you should be able to identify its function.

 

[211]

I'm pretty sure it's an op amp.
Its 14-pins with power and ground on pins 4 and 11 respectively.

 

[carbonzit]

Well, you could probably tell whether it's working or not by tracing the circuit. But so far as actually identifying it goes, probably not, unless you have access to a curve tracer or other sophisticated test equipment.

What kind of equipment is this in? Audio? radio frequency? switching power supply? that could give you some clues.

 

[211]

It's a motion detector. Unbranded.
My guess is it's amplifying the signal from the PIR. It's a really simple circuit and I'm trying to replicate it but modifying the output to drive an LED and motor.

The nice thing about this is it runs off of a tiny 3v battery which makes it small.

I've searched DigiKey for quad op-amp and there's Bazillions of them available. That tells me they're not all the same...

 

[carbonzit]

You could just start with a least-common-denominator type quad op amp, like the LM324. They are all different, but they're all the same, too. In other words, for this application, probably almost any device will work. Won't cost much to find out in any case.

 

[Mr RB]

Show a clear photo of the top and botom of the PCB which shows the other parts connected to the IC, that will help a lot. At this point only YOU have seen the whole circuit so we are at a big loss to tell you what it is!

 

[DerStrom8]

It's a motion detector. Unbranded.
My guess is it's amplifying the signal from the PIR. It's a really simple circuit and I'm trying to replicate it but modifying the output to drive an LED and motor.

I once had an old motion detector that I tore apart, and the chip (14-pin) was an LM324 quad op-amp. Considering your description of the power pins, I think this is probably what your chip is:
**broken link removed**
Der Strom