Two p-n junction diodes $D_1$ and $D_2$ are connected as shown in figure. $A$ and $B$ are input sign

Question

Two p-n junction diodes $D_1$ and $D_2$ are connected as shown in figure. $A$ and $B$ are input signals and $C$ is the output. The given circuit will function as a $\_\_\_\_$ .

Professor PC Thomas Classes · Answer

In the given diode circuit, the output $C$ is taken across a resistor connected to ground. The diodes are configured such that if either input A or B (or both) is at a logic low (0V), the corresponding diode is forward biased and conducts, pulling the voltage at the junction down to near 0V. Only when both inputs A and B are at a logic high (+V) will both diodes be reverse biased, allowing the output C to be pulled high. This operation corresponds strictly to the truth table of an AND gate.