LM5050-1: how to OR two supplies but at any instance, Load current should be drawn from one supply. (ex: tps2350)

Part Number:LM5050-1

Hello Sir/Madam,

I am ORing two 12V supplies which are generated from (ac to dc) & (dc to dc). 

My requirement is, while ORing my load should draw power from any one source. and if one supply goes off, then it should switch to second automatically. 

(this feature I have seen in TPS2350 but it is for negative voltages). While using lm5050-1 , it pulls from both sources.

Please suggest a Part which can do what I am trying to do.

Regards

Vishal Kakade.