PURPOSE: To enable an output to drive another gate without any intermediate buffer by pulling up the input terminal of an inverter and making no DC current flow to the inverter when both input signals are high. CONSTITUTION: When the inputs A and B are both low, neither of transistors(TR) 30 and 31 conducts, TRs 34 and 35 turn on to raise the voltage at a node 41 up to Vc C, and a TR 37 turns on to hold a line 39 almost at the earth voltage. When one of them is high, one of the TRs 30 and 31 turns on to send a zero voltage to the node 41 and a TR 38 turns on to develop the voltage Vc C at an output node 39. When both the inputs are high, both the TRs 30 and 31 turn on to supply an input signal which has dropped by a threshold voltage to the node 41. The TR 38 is cut off by feedback through a TR 40 and the DC circuit of the inverter 36 can be eliminated.
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