Hello again,

My PID job is moving along. I am in the process of making a board and collecting necessary parts.

Here is an interesting problem. The original design uses surface mount components. We are using thru-hole (student/research project, after all). The board calls for a log op-amp AD8304, that is quite nice because it is specialized to work with photodiodes and that is a significant part of the design - the op-amp senses photodiode and sends the signal to PID. I cannot use this op-amp because it is only available in surface mount. I am trying to find a comparable substitute and am currently looking at things like AD606 and AD641 but they seem to be drastically different.

Can anyone point to a thru hole op amp that works well with photodiode detection? I keep looking to.

Thank you.

 

I cannot use this op-amp because it is only available in surface mount.

Can anyone point to a surface mount op amp ......

Thank you.

One of these statements in incorrect.

Can you divide and conquer to give yourself more latitude?
You can make a simple signal conditioner to get a durable signal from the photodiode using many different models of op-amps available to you. Feed that into a discrete or integrated log amp of which you should have numerous options.

 

Sorry about the confusion, I am obviouly looking for a thru hole op amp as I cannot use the surface mount.

Thanks for pointing it out. Still looking...

 

You know, you CAN get adapters so that you can use SMD/SMT IC's with thru hole, right?

 

Thanks, I know about those adapters as of this morning.

It would have been nice to find an alternative op amp that does not require an adapter or look into the option suggested by Jaguarjoe.

 

Texas Instruments has this application note which you may find helpful:
http://focus.ti.com/lit/an/sboa035/sboa035.pdf