Thanks for the link. I can't find a datasheet in the link provided or elsewhere for that particular sensor. In order to design an interface circuit its imperative to know what it gives at the output, bias supply, freq response, transfer function with respect to the O2 concentration, output impedance, etc. If you find the datasheet or any of that info please post here. I have no idea what are those parameters for that sensor neither if it is digital or analog. Request the datasheet from the supplier, they maybe able to provide it.