INVESTIGATION OF HIGH-SPEED PULSE TRANSMISSION IN MCM-D

Experimental investigation of high-speed pulse transmission in an MCM- D module has been carried out. By using advanced CMOS dice (74AC240) a nd a fast comparator (SP93 808), and our high frequency MCM-D technolo gy, it is demonstrated that a long aluminum lossy line (8.0 cm) can li mit the maximum frequency of an MCM-D module. On the other hand, the m aximum frequency is limited by the CMOS circuits when the line length is equal or shorter than 6.0 cm. For a 5.0-cm line, best pulse integri ty is obtained when a 40-OMEGA series resistor termination is utilized . From the half fall time measured with the comparator, the estimated maximum clock frequency in the module is about 1 GHz for a 5.0-cm stri pline with impedance matched termination. Crosstalk is negligible betw een parallel striplines with a 75-mum pitch in the module. On the othe r hand, crosstalk in the module package is observed.