ESD/EOS Filter for ADC Input?

[JayShoe]

Hello,

I'm designing a TLV320ADC6140 module that will be used as the ADC for 2 microphone inputs and a stereo "line level" pair.

The device has "anti-aliasing filters associated with the decimation stage, dedicated high-pass, and then programmable biquads..." and "the only required external components to evaluate the product is the AC coupling cap (which can be shorted out for DC coupled operation)." - TI

I plan on connected dynamic professional microphones such as an SM58 connected to an XLR jack, over a balanced XLR cable. On the other two inputs I plan on connecting a 3.5mm jack which will accept line level signal from devices such as phones, tablets, computers, etc.

I checked with TI and they said that i should consider adding "system level ESD or IEC type transient protection." and said that maybe "add a TVS diode in parallel with a ~100-470pF capacitor". So this is the circuit I have drawn.

We have the following parts:

1. ES1 and ES2 are a TVS Diode with part number TPD1E10B06QDPYRQ1
2. C11 and C25 are a CAP CER 100PF 50V C0G/NP0 0402 with part number C0402C101J5GAC7411

Is this a decent ESD/EOS Filter? We'll be using the microphones in the public with people passing them around and being rough with them in a karaoke environment. The line inputs will be phones, and tablets, plugged and unplugged frequently. Do you think this is a good circuit as an input for our ADC?

Thank you!
Jay

 

[Markw4]

It might be fine. Don't know the environment very well to know what typical protection standards are. IIRC Mackie used to publish schematics of their small mixing consoles in the user manuals. You might try taking a look at something like that to see what people making semi-professional products for sound reinforcement are using in the way of protection.