- #1
ap1993
- 4
- 0
The AND gate
1. When A = 0 and B = 0 both diode D1 and D2 get forward biased and hence conduct. The diodes being ideal, no voltage drop takes place across either diode. Therefore potential difference of 5V takes place across R, with C at zero potential with respect to earth. Thus the output Y is 0 (in level).
2. When A = 0, B = 1, D1 conducts diode D2 will not. Since D1 is ideal, no voltage drop occurs it. Therefore a voltage drop of 5V takes place across R, having D at +5V and C at zero with respect to earth. The output is 0 (in levels).
3. When A = 1, B = 0 for same reason, output is 0.
4.When A = 1, B = 1 none of diodes conduct and so no current flows through R. The potential at C is equal to potential at D which is +5V with respect to earth. Hence output Y is 1.
A B Y
0 0 0
0 1 0
1 0 0
1 1 1
1. When A = 0 and B = 0 both diode D1 and D2 get forward biased and hence conduct. The diodes being ideal, no voltage drop takes place across either diode. Therefore potential difference of 5V takes place across R, with C at zero potential with respect to earth. Thus the output Y is 0 (in level).
2. When A = 0, B = 1, D1 conducts diode D2 will not. Since D1 is ideal, no voltage drop occurs it. Therefore a voltage drop of 5V takes place across R, having D at +5V and C at zero with respect to earth. The output is 0 (in levels).
3. When A = 1, B = 0 for same reason, output is 0.
4.When A = 1, B = 1 none of diodes conduct and so no current flows through R. The potential at C is equal to potential at D which is +5V with respect to earth. Hence output Y is 1.
A B Y
0 0 0
0 1 0
1 0 0
1 1 1