Jotrin Electronics
비고 합계 (USD) 운영
제품과 함께 쇼핑 카트
제품과 함께 쇼핑 카트 : 0
> Other > 74HC02 Quad 2-Input NOR Gate: Datasheet, Pinout, and Circuit

74HC02 Quad 2-Input NOR Gate: Datasheet, Pinout, and Circuit

업데이트 시간: 2023-11-29 13:53:14


In digital electronics, the 74HC02 Quad 2-Input NOR Gate is a cornerstone for countless applications, providing designers with a versatile and efficient building block. This integrated circuit (IC) belongs to the 74HC series, renowned for its high-speed operation, low power consumption, and compatibility with various logic families. In this article, we will explore the 74HC02 datasheet, pinout, features, circuit, and applications, you'll discover the functionality of the 74HC02 IC and how to integrate it into a circuit.

What is 74HC02?

The 74HC02 is a quad 2-input NOR gate. It incorporates clamp diodes on its inputs, allowing the utilization of current-limiting resistors for interfacing inputs with voltages surpassing VCC. The 74HC02 is a member of the 74HC family, which integrates four independent 2-input NOR gates into a single package. Each NOR gate, a fundamental logic gate, produces a high output only when both inputs are low. This simple yet powerful functionality makes the 74HC02 an indispensable component in digital circuits, enabling the creation of diverse logic functions.

Feature & Specifications


  • Wide operating voltage range: 2.0 V to 6.0 V

  • Low power dissipation with CMOS technology

  • High noise immunity

  • Robust latch-up performance exceeding 100 mA per JESD 78 Class II Level B

  • nput levels:

      For 74HC02: CMOS level

      For 74HCT02: TTL level

  • Compliance with JEDEC standards:

      JESD8C (2.7 V to 3.6 V)

      JESD7A (2.0 V to 6.0 V)

  • ESD protection:

      HBM JESD22-A114F exceeds 2000 V

      MM JESD22-A115-A exceeds 200 V

  • Various package options available

  • Specifications provided for temperature ranges of -40 °C to +85 °C and -40 °C to +125 °C


Max Power Dissipation500mW
Propagation Delay15 ns
Quiescent Current2μA
Turn On Delay Time7 ns
Logic Level - Low0.5V ~ 1.8V
Logic Level - High1.5V ~ 4.2V
Current - Output High, Low5.2mA 5.2mA
Output Current25mA
Number of Functions4

What is the use of 74HC02?

The 74HC02 provides four individual NOR gates. A NOR gate produces an output of 1 (HIGH) only when all its inputs are 0 (LOW). Refer to the truth table below for the corresponding output based on different input scenarios:

Truth table for the NOR gate.png

How to use 74HC02 Chip?

Like other chips in the 7400 series, this IC requires a power connection before utilization. Most 7400 ICs operate with a VCC voltage of 5V. A distinguishing factor between the HC and LS versions is that the 74HC02 accommodates a range of 2V to 6V, whereas the 74LS02 is limited to 5V.

Once properly connected, you can utilize any of the four basic NOR gates it houses.

The 74HC02 IC connected to power.png

The 74HC02 IC connected to power

The current capacity for each output varies depending on the specific chip.

74HC02: When powered with 5V, each NOR gate output of the 74HC08 can either sink or source 4 mA.

74HC02 Pinout

The 74HC02 is equipped with 14 pins and incorporates four fundamental NOR gates, arranged as illustrated in the pinout diagram provided:

74HC02 pinout.png

The following is the pin description of 74HC02 IC:

Pin No.Pin NameTypeDescription
11YOutputOutput from the first NOR gate.
21AInputInput to the first NOR gate.
31BInputInput to the first NOR gate.
42YOutputOutput from the second NOR gate.
52AInputInput to the second NOR gate.
62BInputInput to the second NOR gate.
7GNDPowerConnect to ground.
83AInputInput to the third NOR gate.
93BInputInput to the third NOR gate.
103YOutputOutput from the third NOR gate.
114AInputInput to the fourth NOR gate.
124BInputInput to the fourth NOR gate.
134YOutputOutput from the fourth NOR gate.
14VccPowerPositive power supply. Connect to +5V power.

74HC02 CAD Model


74HC02 Symbol.jpg


74HC02 Footprint.jpg

CAD Model

74HC02 3D Model.jpg

74HC02 Circuit

Functional Diagram

74HC02 Functional Diagram.jpg

Test Circuit

74HC02 Test Circuit.jpg

74HC02 Circuit Example

Here's a straightforward project employing the 74×02 IC. The NOR gates form an SR latch, retaining the last output value. It governs an LED that you can activate by pressing the On button. Once activated, the LED remains on even after releasing the button. To deactivate the LED, press the Off button.


To assemble this circuit, you'll require the following components:

  • 1 x 74HC02

  • 1 x LED (L1)

  • 2 x 10 kΩ resistor (R1-R2)

  • 1 x 1 kΩ resistor (R3)

  • 2 x pushbutton (S1-S2)

74HC02 Alternatives & Equivalents

The 74HC02 chip is available in various versions, each maintaining the same functionality but differing in specifications, such as supported voltages and maximum current output.

Here's a compilation of several equivalents of this chip:

74HC02 Application

The 74HC02 is widely applied in diverse digital circuit configurations, encompassing:

  • Logic Gates: Integrate multiple 74HC02 ICs to craft fundamental logic gates like XOR, XNOR, AND, and OR, forming the backbone of digital systems.

  • Flip-Flops and Latches: Construct memory components such as flip-flops and latches utilizing NOR gates.

  • Arithmetic Circuits: Implement adders and subtractors within arithmetic circuits.

  • Data Encoders and Decoders: Employ NOR gates for data encoding and decoding functions.

Moreover, its utility extends to various applications, including:

  • Industrial Automation: Interface with diverse sensors and actuators.

  • Automotive: Employed in power electronic designs.

  • Mobile: Integrated into power electronic designs.

  • Consumer Electronics: Incorporated in power electronic designs.

Maximum Ratings

VccDC Supply Voltage (Referenced to GND)– 0.5 to + 7.0 V
VinDC Input Voltage (Referenced to GND)– 0.5 to VCC + 0.5 V
VoutDC Output Voltage (Referenced to GND)– 0.5 to VCC + 0.5 V
linDC Input Current, per Pin ±20mA
IoutDC Output Current, per Pin ±25mA
IccDC Supply Current, VCC and GND Pins ±50mA

Power Dissipation in Still Air, SOIC Package†

TSSOP Package†



TstgStorage Temperature– 65 to + 150 ℃

Lead Temperature, 1 mm from Case for 10 Seconds

SOIC or TSSOP Packag


Recommended Operating Conditions

VccDC Supply Voltage (Referenced to GND)2.06.0V
Vin, VoutDC Input Voltage, Output Voltage (Referenced to GND)0VccV
TAOperating Temperature, All Package Type-55+125
tr, tf

Input Rise and Fall Time (74HC02 waveforms figure)
Vcc = 2.0 V

Vcc = 4.5 V

Vcc = 6.0 V








74HC02 Waveforms.jpg

74HC02 Waveforms

74HC02 Datasheet

Download 74HC02 Datasheet PDF.

Read More

이전: 4-Bit Binary Counter: Working, Circuit Diagram & Applications

다음: The Ultimate Guide to Implementing NOR Gate from NAND Gate


  • How does a NOR gate work?
  • The NOR gate is formed by an OR gate followed by an inverter. It produces a "true" output only when both inputs are "false"; otherwise, the output is "false."

  • What is the voltage of 74HC02?
  • 2.7 V to 3.6 V.

  • What are the advantages of NOR gate?
  • The NOR gate offers advantages regarding space efficiency, material usage, and ease of implementation.

  • Which is better, NAND or NOR gate?
  • Due to their simpler transistor structure, NOR gates often exhibit higher speed than NAND gates. Furthermore, NOR gates consume less energy than NAND gates, making them advantageous in low-power applications. However, in many VLSI circuits, NAND gates' simplicity and cost advantages often outweigh these benefits.

Ratings and Reviews





라이브 채팅