Universal Logic Gate Chip SN7406N: Equivalent, Working Principle and Package

13 October 2023 26

Ⅰ. What is SN7406N?

Ⅱ. Symbol, footprint and pinout of SN7406N

Ⅲ. Technical parameters of SN7406N

Ⅳ. Features of SN7406N

Ⅴ. Working principle of SN7406N

Ⅵ. Dimensions and package of SN7406N

Ⅶ. Manufacturer of SN7406N

Ⅷ. What are the uses of SN7406N?

Ⅸ. How is SN7406N used to drive high-intensity current loads?

Ⅰ. What is SN7406N?


The SN7406N, often known as a six-channel inverter, is a highly adaptable integrated circuit that contains six NOT gates in a compact package. It is a crucial component in digital logic operations, primarily involved in logic inversion. This means that when it receives a high input signal, it produces a low output, and vice versa, resulting in a high output for a low input signal. Notably, the SN7406N stands out with its open collector output, which has a high voltage capacity. This feature makes it well-suited for interfacing with more complex circuits, such as MOS devices, or for driving heavy loads like lamps and relays.

Furthermore, it acts as a dependable buffer for TTL inputs, ensuring signal integrity and maintaining appropriate voltage levels within digital systems. The SN7406N exhibits a minimum breakdown voltage of 30V and can manage a maximum sink current of 40mA. Typically, its operational temperature range extends from 0°C to 70°C, rendering it suitable for a diverse range of applications across a broad spectrum of environmental conditions.

Replacement and equivalent:



• SN7406NE4



Ⅱ. Symbol, footprint and pinout of SN7406N


The picture above shows the symbol, footprint and pinout of SN7406N. It has multiple pins, including input and output pins, as well as power and ground pins. Its pin names and functions are as follows:

Pin1 (1A): TTL-level inputs

Pin2 (1Y): Open-collector outputs

Pin3 (2A): TTL-level inputs

Pin4 (2Y): Open-collector outputs

Pin5 (3A): TTL-level inputs

Pin6 (3Y): Open-collector outputs

Pin7 (GND): IC ground reference

Pin8 (4Y): Open-collector outputs

Pin9 (4A): TTL-level inputs

Pin10 (5Y): Open-collector outputs

Pin11 (5A): TTL-level inputs

Pin12 (6Y): Open-collector outputs

Pin13 (6A): TTL-level inputs

Pin14 (VCC): Power supply pin

Ⅲ. Technical parameters of SN7406N


Ⅳ. Features of SN7406N

• High sink-current capability

• Minimum breakdown voltage is 30V, maximum sink current is 40mA.

• Six reverse buffers with high voltage outputs

• Can interface with advanced circuits (such as MOS), or drive high current loads (such as lamps or relays)

• It is a TTL hex inverter buffer/driver with a high voltage open collector output and inputs fully compatible with most TTL circuits.

Ⅴ. Working principle of SN7406N

The SN7406N operates on a straightforward principle. It functions as an inverter, meaning it takes the input signal and reverses it for the output. To clarify, when the input pin registers a high-level signal (typically 1), the output pin will produce a low-level signal (typically 0), and the opposite is true as well. This reversal of the output signal characterizes it as an inverter.

Furthermore, it's worth noting that the SN7406N features an open collector design, a distinctive characteristic in digital electronics. This design ensures that the output pin of the SN7406N will establish a connection with the ground only when the input signal attains a high-level state. Essentially, when the input signal is in a low state, the output pin remains unconnected to the ground. This unique feature offers considerable flexibility and utility in various electronic circuits.

Ⅵ. Dimensions and package of SN7406N


The SN7406N, depicted in the illustration, boasts dimensions of 19.05 mm in length, 6.35 mm in width, and 3.3 mm in height. This component is commonly available in two package formats: dual in-line package (DIP) and surface mount package (SMD), with the option to be packaged in a tube. These package options cater to various application requirements, including DIP package for circuit board mounting and repair, and SMD package for situations with limited space or the need for surface mounting.

Ⅶ. Manufacturer of SN7406N

The manufacturer of SN7406N is Texas Instruments (TI). It is a semiconductor multinational company in Texas, USA. It is world-famous for the development, manufacturing, and sales of semiconductor and computer technologies. It is mainly engaged in the research, manufacturing, and sales of innovative digital signal processing and analog circuits. In addition, TI also produces TI digital light processing technology and educational technology products, including calculators, microcontrollers and multi-core processors. It is one of the top ten semiconductor companies in the world.

Ⅷ. What are the uses of SN7406N?

SN7406N is a signal inverter widely used in digital circuits. Its application fields cover many fields such as communications, computers, and industrial control. In the realm of communications, SN7406N plays a pivotal role in facilitating digital signal processing, modulation, and demodulation, ensuring the seamless functioning of communication networks. In the computer sector, SN7406N is frequently harnessed for essential tasks like CPU bus control and memory management, thereby offering robust support for the dependable operation of computer systems. In the field of industrial control, SN7406N is an indispensable part. It provides reliable guarantee for the stable operation of PLC and industrial automation systems, thereby realizing intelligent and efficient industrial production.

Ⅸ. How is SN7406N used to drive high-intensity current loads?

The SN7406N chip employs a three-state logic gate to manage its output state, offering robust current drive capabilities. In a practical circuit, we can link the SN7406N's output terminal to the high-load device to be controlled and manipulate its output state using an input signal. When the input signal is set to a low state, the SN7406N's output will assume a high level, enabling it to power high-intensity current loads. Conversely, when the input signal is at a high level, the SN7406N's output terminal will transition to a low state, effectively interrupting the load current.

It should be noted that when driving high-intensity current loads, the power consumption of the SN7406N itself will also increase accordingly. Therefore, in practical applications, we need to select appropriate drivers and load components based on the size of the load current and the power consumption requirements of the circuit.

Frequently Asked Questions

1. What is the SN7406N?

The SN7406N is a hex inverter/buffer IC (Integrated Circuit) that contains six independent inverter gates. It is a member of the 7400 series of digital logic devices.

2. What is the operating temperature range of SN7406N?

The operating temperature of SN7406N ranges from 0°C to 70°C.

3. What is the function of the buffer in the SN7406N?

The buffer in the SN7406N serves as an output driver, helping to provide a stronger and more stable output signal, especially when connected to other digital components.

4. What is the replacement and equivalent of SN7406N?

You can replace the SN7406N with the CD4049, DM7406N, SN7406NE4 or SN7406NG4.

5. Is the SN7406N still commonly used in modern electronics?

While the SN7406N is a relatively old IC, it can still be found in some legacy systems and educational settings. In modern electronics, newer and more advanced logic families like CMOS (Complementary Metal-Oxide-Semiconductor) have largely replaced the 7400 series TTL logic.