(a) From Table 8-6, determine the noise margins when a 74LS device is driving a 74ALS input.

(b) Repeat part (a) for a 74ALS driving a 74LS.

(c) What will be the overall noise margin of a logic circuit that uses 74LS and 74ALS circuits in combination?

(d) A certain logic circuit has V_IL(max) = 450 mV. Which TTL series can be used with this circuit?

TABLE 8-6 Typical TTL series characteristics. 74S Performance ratings Propagation delay (ns) Power dissipation (mW) Max. clock rate (MHz) Fan-out (same series) Voltage parameters VOH(min) (V) VOL(max) (V) VIH(min) (V) VIL(max) (V) 74 9 10 35 10 2.4 0.4 2.0 0.8 3 20 125 20 2.7 0.5 2.0 0.8 74LS 74AS 74ALS 74F 9.5 2 45 20 2.7 0.5 2.0 0.8 1.7 8 200 40 2.5 0.5 2.0 0.8 4 1.2 70 20 2.5 0.5 2.0 0.8 36 100 33 2.5 0.5 2.0 0.8