Folded-collector integrated injection logic

Folded-collector I/SUP 2/L offers an effective method of controlling the saturation of the n-p-n transistor simply by controlling the ratio of two areas: the area of the output collector(s) and the area of a `dummy' collector. This extra collector is folded back and connected to the input base. The structure improves the minimum delay of the basic I/SUP 2/L gate. Moreover, the structure has many circuit applications where a current scaling factor is required, e.g., threshold and ternary logic. Some of these circuits are given.