Assume vxnbsp vynbsp vznbsp logic 1 and assume two similar

Question

Consider the modified Schottky TTL NAND gate shown in Figure. The current gain of all transistors is β = 20.

(a) Assume v_X = v_Y = v_Z = logic 1 and assume two similar type load circuits are connected to the output. The transistor Q₂ is biased in saturation with i_B2 = 0.1 mA and i_C2 = 0.2 mA. Determine the values of R_B1 and R_C1.

(b) Using the results of part (a), and assuming v_X = 0.4 V and v_Y = v_Z = 1.8 V, determine v_B1, v_B2, v_O , and all base and collector currents. Assume two similar type load circuits are connected to the output.

(c) Assume v_X = v_Y = v_Z = logic 1 and assume four similar type load circuits are connected to the output. Using the results of part (a), determine v_B1, v_B2, v_O , and all base and collector currents.

(d) Determine the maximum fanout for a low output state.