Tampilkan postingan dengan label circuit. Tampilkan semua postingan
Tampilkan postingan dengan label circuit. Tampilkan semua postingan
Minggu, 23 Oktober 2011
Senin, 17 Oktober 2011
DEMORGAN’S THEOREMS
Two of the most
important theorems of Boolean algebra were contributed by a great mathematician
named DeMorgan. DeMorgan’s Theorems are extremely useful in simplifying
expressions in which a product or sum of variables is inverted. The two
theorems are:
Kamis, 13 Oktober 2011
BOOLEAN THEOREMS
We have seen how Boolean algebra
can be used to help analyze a logic circuit and express its operation
mathematically. We will continue our study of Boolean algebra by investigating
the various Boolean theorems that can
help us to simplify logic expressions and logic circuits. The first group of
theorems is given in Figure 1. In each theorem, x is a logic variable that can
be either a 0 or a 1.
Figure 1.single-variable theorems
(
Selasa, 11 Oktober 2011
OR Gates, AND Gates, NOT Gates
Okay….before
thank you for your attention. In this oppurtunity, I will share knowladge about
OR Gates, AND Gates, and NOT Gates.
OR Gate
The OR
operation is the first of the three basic Boolean operations to be learned. In
digital circuitry an OR gates is a circuit that has two or more inputs and
whose output is equal to the OR combination of the inputs. Figure 1 is the
logic symbol for a two-input OR gate. The inputs A and B are logic voltage
levels, and the output x is a logic voltage level. X = A+B, in other words the
OR gate operation in such away that its output is HIGH (logic 1) if either
input A or B or both are at a logic 1 level. The OR gate output will be LOW
(logic 0) only if all Its input are at logic 0. Truth table for a two-input OR
gate.
Figure1.symbol for OR gate and truth table
AND Gate
The AND
operation is the second of the three basic Boolean operation. The logic symbol
for a two-input AND Gate is shown in Figure 2. The AND gate output is equal to
the AND product of the logic inputs, that is x=AB. In other words, the AND gate
is a circuit that operates in such a way that its output is HIGH only when all
inputs are HIGH. For all other cases AND the gate output is LOW. Truth table
for a two-input AND gate.
Figure2.symbol for AND gate and truth table
NOT Gate (INVERTER)
The NOT
operation is the third of the three basic Boolean operation. The NOT operation
is unlike the OR an AND operations in that it can be performed on a single
input variable. The logic symbol for NOT gate is shown in Figure 3. This circuit always has only a single input, and its output
logic level is always opposite to the logic level of this input. Truth table NOT
gate.
Figure3.symbol for NOT gate and truth table
Selasa, 04 Oktober 2011
D/A Converter
There are several methodes and circuits for
producing the D/A converter that has been described. Figure (a) shows the basic
circuit for one of type of four – bit DAC. The inputs A, B, C, and D are binary input that are assumed to have
values of either 0 or 5 V. The operational amplifier show as summing amplifier
operation. The function of Rf is R feed back. The D input has RIN 1
KΩ, so the summing amplifier passes the voltage at D with no attenuation. The C
input has RIN 2 KΩ, so that it will be attenuated by ½. Similarly,
the B input will be attenuated by ¼, and the A input by 1/8. The amplifier
output can thus be expressed as
Logic 0 = 0V
Logic 1 = 5V
