Home > Integrated Circuits > 74 Series > 74HC Series. 74HC – 74HC Quad 2-input NAND Schmitt Trigger Datasheet – Buy 74HC Technical. Manufacturer’s Part Number, 74HC Manufacturer’s Web Site, -. Futurlec Part Number, 74HC Department, Integrated Circuits. Category, 74HC Series. 74HC 74HC/HCT; Quad 2-input NAND Schmitt Trigger;; Package: Product specification File under Integrated Circuits, IC06 September
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The output of an OR gate goes high when any of its inputs A or B, etc. Ways of cascading two-input OR gates to get up to five inputs.
Just make sure the buffer has a fan-in of one in the former case, and a fan-in of two in the latter. Part 4 Practical digital mixed gate and special-purpose logic gate ICs such as programmable logic, majority logic, and digital transmission gate types.
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Also note that OR gates can be directly cascaded to id a compound OR gate with any desired number of inputs. Simple three input diode OR gate. Need to brush up on your electronics principles?
Relatively few dedicated OR gate ICs are available. Six popular OR gate ICs. Figure 17 lists basic details of the six most popular OR gate ICs: Learning Electronics Need to brush up on your electronics principles? Figure 24for example, shows ways of cascading two-input elements to make OR gates with three, four, or five inputs, and Figure 25 shows a three-input OR element and a three-input diode OR gate cascaded to make a compound five-input OR gate.
The 74LS10 and B see Figures 6 and 7 are triple three-input standard types; the 74LS20 and B see Figures 8 and 9 are dual four-input standard types; the 74LS30 and B see Figures 10 and 11 are eight-input standard types; and the 74HC is a input standard type.
Understanding Digital Buffer, Gate, and Logic IC Circuits – Part 3 | Nuts & Volts Magazine
The simplest way to make an OR gate is via a number of diodes and a single resistor, as shown for example in the three-input OR 74nc132 of Figure In this case, the unwanted inputs can be 74gc132 by either tying them high directly in CMOS gates, or via a 1K resistor in TTL types or by simply shorting them directly to a used input.
Example of a compound five-input OR gate circuit. Note that the fan-in of a TTL NOR gate is directly proportional to the number of inputs used — at a fan-in rate of one per input — and that a TTL two-input OR gate can be made to act as a simple non-inverting buffer by either tying one input to ground or by tying both inputs together, as shown in Figure The diode OR gate is reasonably fast, very cost-effective, and can readily be expanded to accept any number of inputs by simply lc one more diode to the circuit for each new input.