MEMS microphones Forum Discussions

[morpheous85]

I'm building a design using a IM73A135.
The datasheet lists a SNR of 73 dBA and an output impedance of 250 ohms in Normal mode.
Can I use 2 of these and tie the positive outputs together (and the negative outputs together) to gain 3dB SNR while having no increase in output level?

It works in a simulation, but I might be missing something.

I know the normal way to do this is through an active mixer using an op-amp.
However, I want to avoid the space/power needed for the op-amp, as well as the level increase.

I was planning on DC coupling the outputs due to space constraints.
How consistent is the DC output voltage from these mics? 

[GeorgeT]

Hi @morpheous85,

I am checking the feasibility of the suggested approach and will update soon.

Thanks and regards,

George

[GeorgeT · Accepted solution]

Hi @morpheous85,

Please note that the suggested approach can be used to improve the SNR.

Also note that microphone DC output is stable over the production.

Thanks and regards,

George

[morpheous85]

Thank you!