Principles, Selection, and Typical Applications of Analog Multiplexer Chip

1 Introduction
In the field of modern communication and data processing, the multiplexer (MUX) serves as a critical device with an irreplaceable role. It selectively combines multiple input signals into a single output signal, enabling efficient utilization of communication channels and reducing system costs. This article will provide a detailed introduction to the definition, principles, functions, and applications of multiplexers across various domains.
2  Principle Analysis of Multiplexer
2.1 What is Multiplexing
A multiplexer is a device capable of receiving multiple input signals and combining them into a single output signal in a recoverable manner. In electronics, a multiplexer (MUX) can select a signal from multiple analog or digital input signals and forward it, routing different selected signals to the same output line. Multiplexing techniques may follow one of the following principles, such as Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), Code Division Multiplexing (CDM), or Wavelength Division Multiplexing (WDM).
As shown in the figure below, multiplexing technology divides the communication channel into several logical sub-channels, each of which is used for transmitting one signal. Therefore, multiple signals can be transmitted simultaneously on the shared communication channel.

2.1 Structure and function of multiplexer
Analog multiplexers typically consist of one or more switches, which can be mechanical, electronic, or solid-state.
A multiplexer has one or more input terminals, one output terminal, and one or more control signal terminals. The control signal is used to select which input signal will be transmitted to the output terminal.
In practical applications, multiplexers typically implement serial/parallel conversion or parallel/serial conversion functions.
2.2 Working principle of multiplexer
The principle of a multiplexer is based on Time Division Multiplexing (TDM) technology. It divides each input signal into a series of time slices and transmits them on the transmission medium in a predetermined order. Specifically, the multiplexer contains a clock source inside to determine the division and scheduling of time slices. During the transmission process, the multiplexer sequentially obtains data for a time slice from each input channel based on the control of the clock source, and combines these time slices into a sequence in order. The demultiplexer at the output end restores the received sequence to the original input signals by identifying the identifier.
The implementation of this principle requires a multiplexer with high accuracy and stability. The clock source must be able to provide a sufficiently high frequency to ensure that each input signal can be transmitted within a time slot. In addition, the multiplexer also needs to have a low bit error rate and high anti-interference ability to ensure accurate data transmission.
In analog multiplexers, it is necessary to ensure signal continuity and avoid instantaneous short circuits during switch switching, so a break before make switching method is usually used.
2.3 Function of the multiplexer
The multiplexer has a wide range of applications in the fields of communication and data processing, and its main functions include the following aspects:
1) Signal multiplexing: A multiplexer can combine multiple input signals and transmit them to one output terminal, achieving signal multiplexing. This greatly saves signal lines and hardware resources in the system, and improves the overall efficiency of the system.
2) Signal selection: The multiplexer can select different input signals for transmission based on the control signal, achieving signal selection. This selection function enables the system to flexibly process and control various signals to meet the needs of different applications.
3) Data transmission: A multiplexer can transmit multiple input signals in a certain order to the output terminal, achieving data transmission and distribution. This function enables the system to conveniently process and exchange data, improving the efficiency of data transmission.

2.4 Application of Multiplexers
The multiplexer has a wide range of applications in various fields, and the following are several typical examples:
1) In the field of communication: In telephone communication systems, multiplexers can combine multiple telephone signals and transmit them onto a single telephone line, thereby achieving efficient utilization of communication channels. In addition, multiplexers are widely used in fields such as fiber optic communication and satellite communication.
2) Computer network: In a computer network, a multiplexer can merge multiple data packets and transmit them onto a single network line, thereby improving the utilization of network bandwidth. In addition, multiplexers are also used to implement functions such as routing and forwarding of network data.
3) Data processing: In a data processing system, a multiplexer can merge and transmit data from multiple data sources to a processor, thereby improving the processing efficiency of the processor. In addition, the multiplexer is also used to implement functions such as data caching and synchronization.
2.5 Technical Details
The performance of a multiplexer is influenced by its internal switching technology, and different types of switches (such as CMOS switches, bipolar transistor switches, etc.) have different characteristics and application ranges.
In modern electronic design, multiplexers are often integrated into a single chip to reduce circuit board space and power consumption, and provide higher integration and reliability.
In summary, the analog signal multiplexer, through its internal switching mechanism, can effectively select a signal from multiple input signals and transmit it to the output terminal. Its working principle and characteristics make it play an important role in various electronic systems

3 analog signal multiplexers
Analog multiplexer integrated circuits (MUXes) play an important role in various electronic and communication systems, mainly used for signal selection and switching. The following are its main application areas:
1) Data acquisition system: The multiplexer allows multiple sensors to share a common analog-to-digital converter (ADC), thereby saving component space, cost, and power consumption. This configuration improves the flexibility of the system and allows for dynamic changes in circuit connections under computer control.
2) Communication system: In communication devices, multiplexers are used to route different signal paths, such as in audio and video switching applications, to ensure smooth signal transitions and avoid clicking and popping sounds.
3) Medical devices: In medical equipment, multiplexers are used to connect multiple biosensors, such as electrocardiograms (ECGs) or blood pressure monitors, for data acquisition through a single ADC.
4) Automatic Test Equipment (ATE): In ATE, a multiplexer is used to quickly switch between different test signals, improving testing efficiency and automation.
5) Audio and video switching: In audio and video devices, multiplexers are used to select different input sources, such as televisions, DVD players, or game consoles, to ensure seamless signal switching.
6) Battery powered system: In portable devices, a multiplexer can be used for power management, enabling the switching of multiple power sources to optimize power consumption.
7) Relay replacement: In some applications, multiplexers can be used as a substitute for small relays for controlling circuit switches, with the advantages of small size and fast response.
8) Optical applications: In optical systems, multiplexers are used for switching and selecting multiple optical signals, suitable for the fields of optical communication and optical sensing.
In summary, analog multiplexer integrated circuits are widely used in various electronic systems that require efficient and flexible signal processing due to their unique signal selection and switching capabilities.

4. Application of specific analog multiplexer chips
Xi'an Siyu Microelectronics Co., Ltd. provides various packaging forms of analog multiplexer integrated circuits with working voltages ranging from ± 5V to ± 20V, including dual four options, eight options, dual eight options, and sixteen options.
4.1  GY506/GY507
GY506/GY507 are both single-chip LC2MOS analog multiplexers, with built-in 16 channels and dual 8 channels respectively. GY506 switches all 16 inputs to the common output based on four binary addresses and an enable input state. GY507 switches all 8 differential inputs to a common differential output based on the status of 3 binary addresses and an enable input. Both devices offer TTL and 5V CMOS logic compatible digital inputs.
GY506/GY507 adopts an enhanced LC2MOS process design, with improved signal processing capability from VSS to VDD, and can operate within a wide range of power supply voltages. These devices can operate with any single or dual power supply within the range of 10.8V to 16.5V. It also has high switching speed and low on resistance characteristics.
4.1.1 Chip Characteristics Description
1) Maximum power supply voltage: 44V;
2) Analog signal range: VSS~VDD;
3) Single/dual power supply;
4) Wide power supply voltage range: 10.8V~16.5V;
5) Low power consumption: 28mW (maximum);
6) Low leakage: 20pA (typical value);
7) The first open and then close switch operates to protect the input signal from transient short circuits;
8) 28 pin SOP, TSSOP, CSOP, WCDIP, WSBDIP, CLCC packages are available.
4.1.2 Internal functional diagram of chip

D. DA, DB: multiplexing end, can be used as input or output end; S1~S16, S1A~S8A, S1B~S8B: source terminal, can be used as input or output terminal; A0~A3: Binary address input terminal; EN: Enable terminal (high level active).
4.1.3 Truth Table

4.1.4  典型应用电路图

4.1.5  质量等级

4.2  GY508/GY509

GY508/GY509均为单芯片LC²MOS模拟多路复用器，分别内置8个通道和双4通道。GY508根据3个二进制地址和一个使能输入的状态，将8路输入之一切换至公共输出。GY509根据2个二进制地址和一个使能输入的状态，将4路差分输入之一切换至公共差分输出。两款器件均提供TTL和5V CMOS逻辑兼容的数字输入。

GY508/GY509采用增强型LC²MOS工艺设计，信号处理能力提高到V_SS至V_DD，并且可以在较宽的电源电压范围内工作。这些器件可以采用10.8V至16.5V范围内的任意单电源或双电源工作。同时还具有高开关速度和低导通电阻特性。

4.2.1  芯片特性说明

1）最大供电电源电压：44V；

2）模拟信号范围：V_SS至V_DD；

3）单/双电源供电, 宽电源电压范围：10.8V至16.5V；

4）低功耗：28mW（最大值）；

5）低泄漏：20pA（典型值）；

6）先开后合式开关动作，从而保护输入信号不受瞬时短路影响；

7）可提供16引脚SOP、TSSOP、CSOP、WCDIP封装和20引脚CLCC封装。

4.2.2  芯片内部功能图

D、DA、DB：复用端，可做输入或输出端；S1~S8、S1A~S4A、S1B~S4B：源极端，可做输入或输出端；A0~A2：二进制地址输入端；EN：使能端（高电平有效）。

4.2.3  真值表

4.2.4  典型应用电路图

4.2.5  质量等级

4.3  GY408/GY409

GY408和GY409均为单芯片LC²MOS模拟多路复用器，分别内置8个单通道和4个差分通道。GY408将8个输入中的一个转换为一个公共输出，由3位二进制地址行A0、A1和A2确定。GY409将4个微分输入中的一个转换为一个共同的微分输出，这是由2位二进制地址行A0和A1所决定的。在这两种设备上的输入都被使能端EN用来启用或禁用，当禁用时，所有通道都关闭。

GY408和GY409采用增强型LC²MOS 工艺设计，使芯片具有低功耗、高开关速度和低导通电阻的特性。所有的通道都采用先开后合的设计，在通道转换时防止瞬间短路。

4.3.1  芯片特性说明

1）采用CSOP-16L和CDIP-16L封装；

2）最大供电电源电压：44V；

3）模拟信号范围：V_SS至V_DD；

4）低功耗：I_SUPPLY < 75 mA；

5）低导通电阻：100Ω（最大值）；

6）先开后合式开关动作，从而保护输入信号不受瞬时短路影响；

4.3.2  芯片内部功能图

D、DA、DB：复用端，可做输入或输出端；S1~S8、S1A~S4A、S1B~S4B：源极端，可做输入或输出端；A0~A2：二进制地址输入端；EN：使能端（高电平有效）。

4.3.3  真值表

4.3.4  典型应用电路图

4.5  小结

上诉列举了几款常用芯片，设计工艺都是相同的，只是性能上有所差异。

详细的功能性能描述和电参数，请参阅相关的产品规格书。

5  多路复用器的优缺点

作为一种重要的通信和数据处理设备，多路复用器具有以下优点：

1）提高信道利用率：多路复用器能够将多个信号合并传输到一个信道中，从而提高了信道的利用率和传输效率。

2）降低系统成本：通过合并多个信号到一个信道中传输，多路复用器减少了系统所需的信号线路和硬件资源数量，从而降低了系统成本。

3）灵活性高：多路复用器可以根据需要选择不同的输入信号进行传输，实现灵活的信号处理和控制。

然而，多路复用器也存在一些缺点：

1）复杂性较高：多路复用器需要较高的精确度和稳定性来确保数据的准确传输和处理。因此其设计和实现相对复杂。

2）依赖时钟源：多路复用器的原理基于时分复用技术需要依赖时钟源来确定时间片的划分和调度。如果时钟源出现故障或不稳定则会影响多路复用器的正常工作。

6  结论

多路复用器作为一种重要的通信和数据处理设备在现代通信与数据处理领域发挥着不可替代的作用。通过了解多路复用器的定义、原理、作用及其应用我们可以更加深入地理解其在各个领域的重要性和价值。随着技术的不断发展相信多路复用器将在未来发挥更加重要的作用为各个领域的发展提供有力的支持。