FASTE 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. With every advance of this magnitude, there arise new considerations that must be kept in mind both by the system designer and the user setting up test procedures. FAST is no exception, and it is these considerations that will be addressed in this application note. This paper represents an attempt to describe the way the FAST logic parts are specified, why they are specified in the way they are, and how the parts may be tested in the qualification lab and at incoming inspection to verify their performance.