CD4071 OR Gate IC : Pin Configuration & Its Applications

The logic gates inputs and outputs can occur in two levels like High, Low, True, False, 0 & 1. An OR logic gate includes two inputs and one output. The OR gate output is high when any of the inputs is high. Similarly, the output is low when both the inputs are low. There are different OR gate ICs are available like 7432 IC, DM74LS32, CD4071 OR gate IC, etc. This article discusses an overview of CD4071 OR gate IC.

What is CD4071 OR Gate IC?

The CD4071 OR gate IC is one kind of CMOS chip including 4-OR gates. Every OR gate includes 2-inputs & there are 4 logic gates incorporated on the IC. So, it is frequently called a Quad two-input OR gate.

The CD4071 is a monolithic CMOS (complementary MOS) IC, designed with two enhancement-mode p-channel & N-channel transistors. These two transistors have similar source & sink current capacities. This integrated circuit includes buffered outputs to expand transfer characteristics by supplying very high gain. From static discharge, all inputs can be protected through diodes toward VDD & VSS.

This CD4071 OR gate IC is mainly used CMOS or complementary MOS transistors technology. It assists in achieving an extensive operating range of power supply, less power utilization & maximum noise margin. This IC is manufactured within 14-lead hermetic DIL/DIP ceramic packages which are suitable in low power applications.

Pin Configuration

The pin configuration of CD4071 OR gate IC is shown below. This CMOS IC includes 14-pins where each pin and its functionality are discussed below.

• Pins – 1, 5, 8, 12 (A1 to A4): A-Inputs of the 4 OR logic gates
• Pins – 2, 6, 9, 13 (B1 to B4): B-Inputs of the 4 OR gates
• Pins – 3, 4, 10, 11 (Q1 to Q4): These are output pins of the 4 OR logic gates
• Pin-7 (GND): This is a GND pin (0V)
• Pin – 14 (VDD): This is a power supply voltage pin that ranges from +3V to +15V

Specifications & Features

The features & specifications of CD4071 OR gate IC include the following.

• OR gate with dual input is Quad Package
• Transition time at 5V is 200ns (Max)
• The typical operating voltage is 5V
• Propagation delay at 5V is 250ns (Max)
• The range of operating voltage is -0.5V to +20V
• Logic high voltage min at +5V is 3.5V
• DC i/p current is ±10mA
• Logic low voltage min at +5V is 1.5V
• Dissipation of power is 500mW
• It is available in different packages like 14-pin GDIP, PDIP & PDSO
• TTL compatibility with less power
• Fan out of two driving 74L/one driving 74LS
• Parametric ratings are 5Volts–10Volts–15Volts
• O/P characteristics are symmetrical
• Input leakage (Max) is 1 µA @ 15V on complete range of temperature

Equivalent CD4071 IC is 74LS32 and alternative ICs are 74LS08, 74LS00, 74LS02, 74HCT04, & 74LS04.
The key points associated with CD4071 OR gate IC mainly include the following.

• This logic gate follows both the laws like associative & commutative.
• Commutative law states that A+B is equivalent to B+A
• Associative law states that (A+B)+C is equivalent to B+(A+C) = (B+C)+A
• In a multiple input OR gate, the inputs which are not used can be connected to enable or logic low pins, one of the inputs used & the not used inputs in ECL logic are kept floating or open.

How to use CD4071 OR Gate IC/Circuit Diagram

To use any of the OR logic gates within the chip, first, we need to connect two pins like VDD & GND to the power supply. Here power supply ranges from 3V to 15V.

Some of the chip versions support up to 20V. The pins like A & B in the IC are the input pins to the 4 OR logic gates. Here, the output will be decided by the inputs, so from the OR logic gates, the outputs are Q-pins.

OR Gate

The operation of the OR logic gate is extremely simple, because this is a two-terminal input OR gate, so this logic gate includes two inputs like A & B correspondingly. The OR gate output is known as ‘Q’.
An OR logic gate is the main logic gate in the electronics field. If any of the i/ps are HIGH/Low, then it gives a HIGH o/p. An OR logic gate includes two otherwise many inputs. The OR gate truth table is shown below.

To utilize the CD4071 CMOS IC, this IC must be powered with the pin 14 (Vcc) & pin 8 (GND) lines. This IC’s typical operating voltage is +5V, however, it can also function with 5, 10 & +15.

The o/p voltage of the CD4071 OR gate IC on the pin-Q will be equivalent to the operating voltage of the IC. According to the truth table of the OR gate shown above, once either one or both the logic gate input is high then the output will be maximum. The CD4071 IC circuit diagram with working is shown below.

The logic gate’s input can be controlled with the help of a switch that is connected to pin-A & Pin-B of the logic gate. A 100k pull-down resistor is utilized to hold the logic 0 once the switch is floating on the left side. The output can be visualized through a connected LED toward the output pin-Q. Another resistor like 680R is employed within the circuit to restrict the flow of current throughout the LED.

Where to use/Applications

In digital electronics, the CD4071 OR gate IC is used in different applications of circuits.

• Encoders & Decoders
• Any size of multiplexers and demultiplexers can be designed
• Basic logic circuits otherwise alarm circuits can be designed like an alarm system for a car door.
• Oscillator circuits
• Networking & digital systems

Thus, this is all about an overview of a CD4071 OR gate IC datasheet. The commonly available OR gate ICs are; Quad input 74LS32 IC (TTL Logic Gate), Quad two input CD4071, Triple input CD4075, Dual four input CD4072.

Additionally, this CD4071 OR gate IC permits design engineers to implement the +ve logic OR gate function & enhance the existing CMOS gates family. The CD4071 OR gate IC features high noise immunity & fixed protection throughout clamping diodes. This IC operates at different voltages like 5, 10 & 15. When this IC operates at 5 volts then, it provides the highest low-level Vin = 0.5V & the lowest high-level Vin = 4.5V. Here is a question for you, what is CMOS technology?