I recently had a few prototype boards made, and the pads for a dual op amp were placed on the wrong side of the board. An engineer at the PCB company said he had a possible solution of replacing the intended LM358 with another component. The change was made and the boards sent to me to test. It turned out that it was a better scenario since the magnetic field sensor connected to the op amp was less sensitive than in my breadboard testing, which was a good thing in my case.

Fast forward a couple of months and I'm ready to order more boards, but nobody at the company knows what this replacement component is (great record keeping and shame on me for not asking previously). That particular engineer is no longer with the company. I exhausted my search for the component based on the top marking.

So my question is, what possible component could be placed on these pads and give the lower sensitivity output? I have attached a marked image showing what signals correlate to each pad.

Or maybe somebody knows what this component is based on its marking.

Thanks, as usual, for all the help provided at this forum.

Troy

 

You might narrow the field a little by looking at how/if the inputs are biased and the voltage range seen at the output. This might reveal if the op-amp is rail-to-rail, single or dual supply.

 

With a bit of luck you may still be able to find out.
The component is mounted upside down. If you unsolder the component you might find the marking on the top side.

 

With a bit of luck you may still be able to find out.
The component is mounted upside down. If you unsolder the component you might find the marking on the top side.

Interesting. How can you tell it is upside down? I unsoldered it and there are no markings on the other side.

 

Because that is a standard pin-out for 8-pin dual op-amps, including LM358.

 

Corre

Because that is a standard pin-out for 8-pin dual op-amps, including LM358.

Yes, the most obvious solution would be to solder the component upside down, but when I found no markings on the other side I thought that meant it was right side up. How often do you find components with markings only on the bottom side?

 

Corre


Yes, the most obvious solution would be to solder the component upside down, but when I found no markings on the other side I thought that meant it was right side up. How often do you find components with markings only on the bottom side?

Only when someone intentionally removes the ID markings on the top side.

 

Can you supply a circuit schematic showing the intended application?
Maybe someone can suggest a better op-amp.