Help to identify logo/chip [Solved]

[ace1903]

I am trying to find intermittent problem on Testo flue gas analyzer. I have two chips in signal chain that I can not identify.
Most likely ESD protection or analog switches. 0501 is probably date code and SDA is chip marking.
Logo is circle with P inside. Looked for logos on net and closest I can find is Plessey semiconductors but they seems do only LEDs and optoelectonics.
If anyone have some info to share I will be grateful.

[DavidAlfa]

This was a hard one  . Protek devices:

No idea about the part number, definitely not a HCPL-0501

Check their catalogue:
http://www.protekdevices.com/xyz/documents/kb/tech/gl1123.pdf

[ace1903]

@DavidAlfa - You nailed it. This part number SMDA05CN-5 looks like potential match.
Will look more at the catalogue. I guessed ESD protection but this is like more TVS protection.
Now I am unsure if TVS also covers ESD but for sure that is not the cause for the intermittent problem that I have.
Those devices  have electrochemical sensors that leaks and destroy the PCB but I did regular maintenance of mine device and I am sure that is not the cause.
Thanks DavidAlfa.