Junction isolated thyristors for PBX switching

THE DEVELOPMENT of a junction isolated thyristor for analog speech path switching has resulted in a novel conception of monolithic integration of large cross-point arrays for Private Branch Exchange (PBX) application. Despite stringent technical requirements such as excellent transmission properties and system characteristics, the demand for an extremely economical solution have been fulfilled. This has been achieved by using a standard low-cost bipolar technology with conventional junction isolation and a conception based on LSI principles. The thyristor to be described (Figure l/Table 1) is a switching element in a cross-point circuit comprising a 5x5X2 switching matrix and an on-chip selection control logic in I2L