Single ended to differential mic signal driver recommendations

Question

Anyone have recommendations for single ended to unity-gain differential signal drivers for microphone signals at low output impedance, noise, and quiescent current (<5mA)? I see some chips like LTC6363-1 and LT6350 but these indicate SAR optimization. My application would interface with a downstream ADC/preamp which I presume falls into sigma-delta category. Would these types of chips by an issue? Looking for compact solution that eliminates delays, cascading noise, etc. Thanks in advance for any input.

DaveThib · Accepted Answer

Hello Kapila, 
 You kind of are describing two different applications. An ADC will usually require an input level that is higher than a mic level signal. Although it does depend on what the AVDD voltage the part is operating on. Our newer parts that run on 1.8V require a small signal as a full-scale input. 
 I captured this circuit from the AD1938 datasheet. It is an older design and you will probably not like the way it inverts. 
 
 It is meant to drive an ADC with a 3.3V power rail that is sitting up at around a 1.5V common mode voltage. This is a very common circuit and can be a good starting point. 
 Even though this is a good audio question, you are probably better to ask this on the linear amplifiers section of the forum. (+) Amplifiers - EngineerZone (analog.com) 
 I think they should be able to help and also try searching that forum space for answers. 
 
 Dave T)

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Single ended to differential mic signal driver recommendations