Data Transmission Project at NIKHEF

Project Description:

Analogue data of the HELIX chips on the hybrid has to be transferred to the ADC modules. We expect that:

• cables from the hybrid are connected to a patch-panel at the rear of the RCAL
• from there the signals go over thicker cables to a receiver: either a separate module or the input stage of the ADC module
• earth connections to be defined; NIKHEF will suggest a solution
• the number of bits required for the dynamic range is 10 bits
• the required precision for the full range is not better than 5%
• the least significant bit is equivalent is to be defined; we assume 1/4  of the noise level for the moment

The responsibility of NIKHEF is:

• cables from detector patch-panel to the adc-crate tower,
• the link electronics , 
• the cables to the ADCs

In collaboration with the designers of the hybrid and the ADC modules the analogue connection has to specified in detail. This includes eventual calibration and control of the link.

The transmission over a copper connection has been measured at the required 10 MHz over 50 m.  It is sufficient and this solution has been chosen. The alternative of an analogue optical solution has been cancelled.

Work Schedule:

preliminary definition of link	end of January 98
design to be presented	end of February 98
order parts and print	April 98
have prototype ready for tests with prototype ADC at DESY	July 98
second prototype	4Q98
test with ADC	3Q99
installation	1Q00

Personnel Required initially:

For the starting phase: 1 designer for 4 months