LVI Enable Circuit
Original Publication Date: 1983-Dec-01
Included in the Prior Art Database: 2005-Feb-08
The Low Voltage Inverter (LVI) logic circuit shown in Fig. 1 is described in detail in [*]. The circuit in Fig. 2 extends the logic capability of the LVI logic circuit. The enable function turns off the logic gate so that input signals to IN1 and IN2 would be ignored. The output of the circuit remains at a logic high level. To disable the logic circuit, a special logic high level, which is higher than the normal LVI logic high level, is applied to the enable line. This signal turns on transistor T3 which in turn does not permit transistors T1 or T2 to turn on regardless of the normal LVI logic levels applied to either input IN1 or IN2. Therefore, the output signal remains at a logic level high.