INTRODUCTION
FAST is a second generation Schottky logic family that utilizes advanced oxide-isolation techniques to increase the speed and decrease the power dissipation beyond the levels achievable with conventional junction isolated families. The improved performance of the family is exhibited in two ways — first, the speed and power characteristics of the devices are improved, and second, the conditions under which speed and power are specified are much tighter. For instance, LS and S TTL families offer AC limits only at a nominal +5.00V VCC supply voltage and at room temperature, 25°C.

By contrast, FAST guarantees improved AC performance and specifies that performance over a supply variation of +5.00V ±10% and at temperatures from 0°C to 70°C. Thus the designer no longer needs to derate his propagation delays from the data sheet limits to compensate for speed degradation over the temperature range.