Question

We can apply the previous process to more complicated circuits, with multiple inputs. For each transistor, we check the voltage of the input connected to it and replace the transistor with an open or short, as detailed on the previous page.

A transistor circuit has two input gate. Input VA is connected to one PMOS and one NMOS. Likewise, input VB is connected to one PMOS and one NMOS.

If VA=0V and VB=0V, draw the circuit, replacing the transistor with open or closed switches. Trace the path of Vout to either 5V or ground. Is the output HI or LO?

Answer 1

When VA=0V and VB=0V, the circuit can be drawn by replacing the transistors with open or closed switches. In this case, since both VA and VB are 0V, the PMOS transistors will be OFF and the NMOS transistors will be ON. Consequently, the path of Vout will be connected to ground, resulting in a LOW output.

Step-by-step explanation:

To draw the circuit when VA=0V and VB=0V, we can replace the transistors with open (OFF) or closed (ON) switches based on their inputs. Since VA and VB are both 0V, the PMOS transistors will be OFF and the NMOS transistors will be ON. This means that the current will flow through the NMOS transistors and the PMOS transistors will be open. Therefore, the path of Vout will be connected to ground (0V), resulting in a LOW (LO) output.