Hello,
We're building a very basic sound detection circuit that listens to instrument sounds (repetitive loud beeps) and sleeps most of the time. The frequencies I want to detect are 700MHz, 1kHz, 1.5kHz, 2.2kHz, running a simple FFT algorithm on an ATMega328p. This is a low power application and I've managed to bring down the average current consumption to ~4mA (in 24hrs). So, the low power part is really important. The sampling rate on the ADC is 18kHz. Very basic stuff.
We've used electret mic breakout boards from Adafruit that had the MAX4466 chip which were very nice. Now we're looking for our own PCB, and we've had an excellent experience with JLCPCB and would like to continue using that service. Our initial design used the classic TI-OPA344 (sound detected perfectly fine so those noise/bw/slewrate specs work) but JLCPCB and LCSC have run out of stock and we can't continue using that. I've searched high and low for something that would be equivalent to the OPA344 if not on par with the MAX4466.
Can someone please suggest an alternative?
I'm not an audio person, and we're not looking for the best audio experience, just enough to detect the frequencies I mentioned.
I've tried looking at OPA333 but it has very low slew rate and very noisy above 1kHz. The AD8605 has a high supply current (1mA). The LMV321 has the same issue.
Is there any general-purpose/instrumentation/other op-amp that I can use as a suitable low power alternative?
Any other specs needed to narrow this choice down?
We're building a very basic sound detection circuit that listens to instrument sounds (repetitive loud beeps) and sleeps most of the time. The frequencies I want to detect are 700MHz, 1kHz, 1.5kHz, 2.2kHz, running a simple FFT algorithm on an ATMega328p. This is a low power application and I've managed to bring down the average current consumption to ~4mA (in 24hrs). So, the low power part is really important. The sampling rate on the ADC is 18kHz. Very basic stuff.
We've used electret mic breakout boards from Adafruit that had the MAX4466 chip which were very nice. Now we're looking for our own PCB, and we've had an excellent experience with JLCPCB and would like to continue using that service. Our initial design used the classic TI-OPA344 (sound detected perfectly fine so those noise/bw/slewrate specs work) but JLCPCB and LCSC have run out of stock and we can't continue using that. I've searched high and low for something that would be equivalent to the OPA344 if not on par with the MAX4466.
Can someone please suggest an alternative?
I'm not an audio person, and we're not looking for the best audio experience, just enough to detect the frequencies I mentioned.
I've tried looking at OPA333 but it has very low slew rate and very noisy above 1kHz. The AD8605 has a high supply current (1mA). The LMV321 has the same issue.
Is there any general-purpose/instrumentation/other op-amp that I can use as a suitable low power alternative?
Any other specs needed to narrow this choice down?