In the TTL circuit in Figure, the transistor parameters are βF = 20 and βR = 0.10 (for each input emitter).
(a) Calculate the maximum fanout for vX = vY = 5 V.
(b) Calculate the maximum fanout for vX = vY = 0.1 V. (Assume vO is allowed to decrease by 0.10 V from the no-load condition.)