I am a Mechanical Engineer who needs help in selecting an alternative to an OPA2365 op amp.
I will try to provide as much relevant information as possible, please bear with me.
> I have a schematic that uses the dual op amp OPA2365 as a non-inverting band pass filter (A) followed by an inverting band pass filter (B) for signal conditioning.
> The gain on the A circuit is 100, and the gain on the B circuit is 121.
> The input signal is a noisy sine wave, and the frequency runs from zero to about 1 kHz.. And the signal amplitude also varies to further complicate things; amplitude in the mV range.
> The OP2365 apparently has some desirable characteristics, such as low distortion, high CMRR, rail to rail input and output and runs as a single supply from 2.2 to 5.5V.
> The output goes to a separate comparator that does final clean up of the signal for input into a frequency counter.
> I have attached a PDF of the schematic. The input signal starts at P1 to the left.
> The main problem for me is that the OPA 2365 is surface mount. I am seeking a DIP 'good enough' replacement, but op amps apparently have dozens of performance values, and I don't know which ones to pay attention to, and which ones can be ignored. For example, it seems overkill to spec a 50 mHz part for a 0 - 1 kHz signal, but perhaps there is a reason for that.
> The comparator is a Maxim MAX9031AUK+T that simply outputs when the input signal from the OP2365 crosses 0.55xVcc. It also is a surface mount, so any suggestions for replacing it with a TI DIP are also welcome.
> I will answer any questions that I can. Note that this is purely for hobby purposes, and not for design or production.
