Increasing SNR Through Parallel Microphones

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morpheous85
Level 1
Level 1
First reply posted First question asked Welcome!

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? 

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1 Solution
George_T
Moderator
Moderator
Moderator
50 likes received First question asked 250 replies posted

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

View solution in original post

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3 Replies
George_T
Moderator
Moderator
Moderator
50 likes received First question asked 250 replies posted

Hi @morpheous85,

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

Thanks and regards,

George

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George_T
Moderator
Moderator
Moderator
50 likes received First question asked 250 replies posted

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

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morpheous85
Level 1
Level 1
First reply posted First question asked Welcome!

Thank you!

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