A fast 1024-bit bipolar RAM using JFET load devices

IT HAS LONG BEEN recognized that the need for compact load devices is one of the main problems in building dense bipolar integrated circuits. In recent years several quite promising new approaches to this problem have been developed, including: (1) very high value P-type resistors made by ion implantation (2) the use of lateral PNP transistors to supply and limit the operating current ( I2L) and (3) various kinds of vacuum-deposited resistive materials. The JFET loads to be presented provide yet another way of achieving very compact load elements in bipolar integrated circuits