Query regarding SSM2167

Hi Team,

I am planning to use SSM2167 in one of our audio application project. I have some query regarding the part. Our input voltage at pin no 5 from mic is of 1mV rms. Is the mentioned part capable to identify this low voltage?

 If not can you please suggest a preamp of similar type having noise gate & compression ratio control which will be able to read 1mV rms reliably.



  • 0
    •  Analog Employees 
    on Sep 20, 2018 1:33 PM over 2 years ago

    Hello Sayantan,

    The SSM2167 is not a microphone preamplifier, it is for conditioning a microphone signal so it has some gain to be able to adjust the dynamic range of the signal but not enough to actually work as a preamplifier.

    You did not mention what level you will need to come up to and also if the 1mV rms is the full-scale output or the average output. So I will assume this is the max level which you may want to bring up to 0dBV. In that case you will need 60dB of gain. That is a lot. You may have to use some of our parts from the linear amplifiers group to build a preamplifier with up to 60dB of gain.

    What we do have in the audio parts catalog that comes close is the front end of the ADAU1361. The PGA has a max gain of 35dB but there is a 20dB boost available after the PGA to result in 55dB of gain. Then this part does have an ALC feature to do some compression and you can directly route the input mixer signal to the output mixer and bypass all ADC and DAC conversion should you desire this.

    If you really want to get fancy and do much more then you can go to the ADAU1761 which has the same input and output mixers but adds a DSP. Then you can do a lot of signal processing and you can actually drive the PGA from within the DSP allowing you to do some advanced conditioning of the sidechain signal that is driving the PGA.

    Dave T