Design and Construction of an ALICE SDD End-Ladder Prototype Board

The paper explains the design and the construction of a prototype of an End_Ladder card for the ALICE SDD experiment. The final End_ladder card will receive an input dataset from the front-end electronics and will transmit the elaborated dataset through an optical channel to the counting room. The proposed prototype card includes an actual ALICE SDD End_ladder prototype card with all the components foreseen for the final version. This is designed together with an external larger card with all the testing equipment required for measurements in lab. The End-Ladder card matches the final dimensions while the external larger one provides all the connectors and an optical receiver mirror unit for an easy-to-use complete system. The final optical modules are provided into the End_Ladder prototype card and are composed of 2-photodiodes and 1-laser single-mode 1310nm with their single mode fibers. Once the front end dataset enters the prototype, a small size digital rad-hard chip caries out a bidimensional compression and acts as a JTAG switch for the front end electronics. The incoming dataset is then compressed, packed, serialized and output via a 800Mb/s optical link to the external receiver card of the prototype. The mirror receiver card deserializes the stream and re-constructs the original dataset before being compressed.