The 74HC; 74HCT is an 8-bit buffer/line driver with 3-state outputs. The device can be used as two 4-bit buffers or one 8-bit buffer. Buffers: vs is an octal unidirectional buffer. The 8 lines can be split into two groups and each group can be individually. Electrical Engineering Glossary of Electronic Terms, 8-Bit Buffer IC, functional schematic diagram, true table and package out-line. 74HCT

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The output value will be “Z”, the impedance is approaching infinity. The output value is 0, which means no current. Because the output current is generated by the voltage source via buffer, the buffer acts as a barrier between the source and load, thus preventing the load resistance affecting the source network.

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Glossary of Electronic and Engineering Terms, IC 8-Bit Buffer Description

Other than size, Buffwr Inductance is the next important issue because it slows down switching time, while the size of the IC package causes the placement of the capacitor to move away from the power leads of the IC. It draws very little current and will not disturb the original circuit. It reads an input and outputs a value.

Note the part number suffix is omitted. The output value will be high if and only if the input value is high. It is also called a unity gain buffer because it provides a gain of 1, which means buvfer provides at most the same voltage as the input voltage, serving no amplification function.

A digital buffer serves to transfer a voltage from a circuit that has a high output impedance level, to a second circuit 7444 a biffer input impedance level. A voltage buffer always has a very high input impedance, approaching infinity; as a result, no matter what value the load impedance is, the source voltage will be totally spanned on the buffer impedance because of Ohm’s law ; the voltage across the buffer impedance is the input voltage.


Because the resistance is infinity, the circuit will draw very little current, and will not disturb the original circuit. Data input is active but control input is inactive. However what is 7424 in the IC family may also come into play. A bus can only read one data input from a device at one time, and that is when a tri-state buffer is applied.

Buffers: 74244 vs 74245

Both the data and the control input are inactive; the buffer shuts down. Although we allow the data transmission by turning on the control input, we don’t have data coming in because of the infinite resistance. This page was last edited on 19 Septemberat Regardless of the family used, just be sure to provide by-pass next to the IC.

So the outputs could be taken tri-state if required. The digital buffer is important because it can control the on and off of data transmission, which is used widely in the world of registers sophisticated data storage device and buses data transferring device. That’s what can be delivered faster, or has a lower lead time, or faster deck date. Also, if possible run a larger trace to the IC or capacitor to insure the chip has the highest possible chance of getting the current it needs as fast as possible.

Pick a series [54x] if need the temperature range, otherwise use the series [74x]. The functional IC is split into two 4-bit sections, so they could be operated together or separately, driving one 8-bit bus or two separate 4-bit buses.

Graphically, it is often represented as a triangle with a small circle attaching to the tip. A typical digital buffer that is used to control multiple data inputs written onto a bus is a Tri-State Digital Buffer, which controls the data flow by “tri-state” pins.


A control input is analogous to a valve, which controls the data flow. Also refer to Logic Family vs Switching Speed. Design Hint; Because this chip is used to drive a bus, which may be capacitive loaded, use more than the normal by-pass capacitor to insure that the IC has the current it needs when the buffers begin to drive the bus. The inverter is a basic building block in digital electronics.

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– Octal buffer/line driver; 3-state; non-inverting – ChipDB

These buffers are normally available in a number of package styles; however only the surface mount PSOP is shown. This kind of buffer produces the state opposite to buffwr input.

The type or family of buffer used does make a difference in the table above, just the trailing digits that indicate the type of buffer [as in the different options].

It is basically the same as active high digital buffer except the fact that the buffer is active when the control input is at a low state. Add a second by-pass capacitor, and place both by-pass capacitors as close to the Vcc line as possible.

The location of the bypass capacitor is extremely important; read more on Capacitor Placementas it applies to IC by-passing. From Wikipedia, the free encyclopedia. It does not invert or alter its input signal in any way.

If we have a power source and a low impedance resistor load without a buffer, according to Ohm’s law voltage is equal to current bufcer resistancea huge amount of current is drawn from the source.

A Tri-state buffer, with its control input, can prevent a bus from reading excessive input.

The output value will be 1 and current will flow through the element.