The design of the CDF Run 2 calorimetry readout module

The CDF Calorimetry Readout module, called the ADMEM, has been designed to contain both the analog circuitry which digitizes the phototube charge puls es, and the digital logic which supports the readout of the results through the CDF Run 2 DAQ system. The ADMEM module is a 9Ux400mm VMEbus module, wh ich is housed in a CDF VMEbus VIPA crate. The ADMEM must support near deadt imeless operation, with data being digititized and stored for possible read out every 132ns or 7.6 MHz. This paper will discuss the implementation of t he analog and digital portions of the ADMEM module, and how the board was l aid out to avoid the coupling of digital noise into the analog circuitry.