1. Overview

Analog switches, multiplexers, and demultiplexers are semiconductor devices used to route analog signals in electronic circuits. These ICs enable the controlled connection or disconnection of signal paths, allowing dynamic signal management in applications such as data acquisition systems, communication networks, and industrial automation. Their ability to handle analog signals with minimal distortion and high reliability makes them critical components in modern electronics.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
Analog Switches	Single/multiple pole-switch configurations, low on-resistance, high off-isolation	Signal routing in test equipment
Multiplexers (MUX)	Selects one of multiple input signals, bandwidth up to GHz range	Sensor signal aggregation in IoT devices
Demultiplexers (DEMUX)	Routes single input to multiple outputs, complementary to MUX	Data distribution in communication systems

3. Structure and Components

These ICs typically employ CMOS technology with MOSFET-based transmission gates. Key components include control logic circuitry, channel selection decoders, and bidirectional signal paths. Common packages include TSSOP, QFN, and SOIC with pin counts ranging from 8 to 100+ for high-channel-density devices. Internal structures incorporate ESD protection diodes and charge pump circuits for rail-to-rail operation.

4. Key Technical Specifications

Parameter	Description	Importance
On-Resistance (RON)	Resistance when switch is closed (typical 0.1-100 )	Affects signal integrity and power loss
Off-Leakage Current	Current flow when switch is open (nA/pA range)	Determines isolation performance
Bandwidth	Maximum signal frequency supported (DC to GHz)	Limits high-speed application capability
Channel Count	Number of independent switches (1 to 32 channels)	System integration level
Supply Voltage	Operating voltage range (1.8V to 40V)	Compatibility with system power rails

5. Application Areas

Key industries include:

• Telecommunications: Base station signal routing
• Industrial Automation: PLC signal switching
• Consumer Electronics: Audio/video source selection
• Medical Devices: Multiparameter patient monitoring
• Test Equipment: Automatic test system signal matrix

6. Leading Manufacturers and Products

Manufacturer	Product Series	Key Specifications
TI (Texas Instruments)	TMUXHS4212	10-channel, 0.8 RON, 1GHz bandwidth
Analog Devices	ADG419	4-channel SPST, 15V operation
NXP Semiconductors	74LVC4051	8-channel MUX/DEMUX, 32MHz bandwidth
ON Semiconductor	NCV8456	16-channel DEMUX, automotive qualified

7. Selection Guidelines

Key selection criteria:

• Signal bandwidth vs. R_ON tradeoff
• Operating voltage compatibility
• Package size vs. channel density
• Logic interface voltage levels
• Thermal management requirements

Case Study: In a precision data acquisition system, a 16-channel MUX with <1 R_ON and 10nA leakage current was selected to maintain 16-bit measurement accuracy across 0-10V industrial sensor signals.

8. Industry Trends

Current trends include:

• Development of sub-1 R_ON switches for power-sensitive applications
• Integration of fault protection and diagnostics
• Expansion of radiation-hardened devices for aerospace
• Adoption of wafer-level chip-scale packaging (WCSP)
• Emergence of software-configurable analog routing matrices