74AS00 Quad 2-Input NAND Gate. Physical Dimensions inches (millimeters) unless otherwise noted (Continued). Lead Plastic Dual-In-Line Package ( PDIP). 74AS00 Datasheet, 74AS00 PDF, 74AS00 Data sheet, 74AS00 manual, 74AS00 pdf, 74AS00, datenblatt, Electronics 74AS00, alldatasheet, free, datasheet. description. These devices contain four independent 2-input positive-NAND gates. They perform the Boolean functions Y = A • B or Y = A + B in positive logic.
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The first two conditions show the normal totem-pole operation. To present basic characteristic and limitations of gates. This is called the high impedance or Hi-Z state.
Measure both the input voltage and the logic output of the inverter. Digital logic is implemented using integrated circuits which are ddatasheet into families based on their basic electronic structure. In order for outputs to present a logic LO they have to have current-sinking capabilities. Let us examine the typical totem-pole output once again.
Construct and test this circuit. What is the difference between open collector, tri-state and totem-pole outputs? What is the lowest value of R such that the output is still HI?
What is the minimum and maximum frequency of oscillation?
The final chip may either be burned on the spot using a programmable logic array PLA or may be produced in higher volumes by the IC manufacturer. Conversely, when Q3 is open, Q4 is closed. Regardless of the IC’s complexity or how it is created, basic knowledge of gates and flip-flops is still essential. The tri-state bus driver has an enable input G.
What is the voltage range that would be considered a logic LO? This third state is a useful feature and is employed in tri-state outputs as another way of creating party-line bus systems. Observe here that the circuit elements associated with Q4 in the totem-pole circuit are missing and the collector of Q3 is left open-circuited, hence the name open-collector.
What is the meaning of hysteresis? These two tend to be directly related, i.
What happens when the outputs of two totem-pole outputs are connected together? Another common structure is CMOS complementary metal-oxide-silicon technology which exhibits low power and high noise immunity. What is meant by tri-state 74sa00 3-state outputs? Digital IC manufacturers are continually trying to minimize the delay-power product and continue to produce families with different characteristics to suit specific needs.
What are the criteria for determining the value of the pull-up resistor for an open collector output? What is the smallest value of R such that the output is still LO?
How is the frequency affected by values of R and Datashedt Analyze the circuits and explain the results. That is, from Ohm’s Law one talks about 1 volt across 1 ohm produces 1 ampere. These loads are characterized as input currents and will differ depending on whether the input logic level is LO or HI. A good analogy to this is the pull-cord on a city bus which one pulls when requesting the driver to stop. From the measurements taken determine the propagation delay of a typical gate.
Bus datasheeh with tri-state outputs daatsheet connected together to create a bus system. Families can be characterized by the relationship between propagation-delay and power. At any time, only one of the two switches is closed while the other is open. The propagation delay inherent in gates can be useful for creating oscillatory circuits. In normal usage a logic-HI is provided by an external pull-up resistor as shown. An unconnected input is said to be floating. Study the feedback circuits shown and daasheet the oscilloscope to examine the signal at different stages in the circuit.
(PDF) 74AS00 Datasheet download
When and why would you use tri-state and open-collector outputs as opposed to totem-pole outputs? Calculate the range of values for this resistor. To give students a datasheeg of the magnitudes of voltage, current, resistance, capacitance, time, frequency, etc. Open-Collector Output Figure 6.
Why is negative logic commonly used? Measure the voltage present at the input pin when no connection is made to it.
(PDF) 74AS00 Datasheet PDF Download – Quadruple 2-Input Positive-NAND Gates
Construct the circuit shown and study how the frequency and duty cycle are affected by R2 and C. What is the maximum current flowing through the outputs in c? In contrast with a normal totem-pole output, it cannot be the source of current and therefore cannot present a logic-HI on its own.
Use a 1K potentiometer to supply a variable input voltage.
Draw the input and output waveforms timing diagram.