**ADG408BRU: A Comprehensive Technical Overview of the 8-Channel CMOS Analog Multiplexer**
The ADG408BRU is a monolithic, CMOS-based, single-pole, 8-throw (SP8T) analog multiplexer, designed to handle a wide range of analog switching applications. It serves as a fundamental component in data acquisition systems, instrumentation, and communication systems, where routing analog signals from multiple sources to a single destination with high precision is paramount.
**Core Architecture and Functionality**
At its heart, the ADG408BRU integrates eight analog switches, a decoder circuit, and level-shifting logic. The device selects one of eight independent input/output channels (S1-S8) and connects it to a common output/input (D), based on the 3-bit binary address lines (A0, A1, A2). An enable pin (EN) is provided to disconnect all switches, placing the multiplexer in a high-impedance state, which is crucial for simplifying bus sharing and system power-up/down sequences. The **CMOS construction ensures exceptionally low power dissipation** and high switching speeds, making it suitable for portable and battery-powered equipment.
**Key Electrical Characteristics and Performance**
The performance of the ADG408BRU is defined by several critical parameters that directly impact signal integrity.
* **Low On-Resistance (RON):** A primary feature is its **low and flat on-resistance, typically 5 Ω**. This minimizes insertion loss and distortion of the analog signal being switched, which is vital for maintaining accuracy in precision measurement systems.
* **High Off-Channel Isolation:** The device exhibits excellent off-channel isolation, meaning when a switch is off, it effectively blocks the signal from the common line, preventing crosstalk between channels.
* **Low Charge Injection:** Charge injection is a phenomenon where a small amount of charge is transferred from the switch's control circuit to the analog signal path during switching transitions. The ADG408BRU is designed for **low charge injection**, which is critical for maintaining stability in sample-and-hold circuits and reducing glitches in the output.
* **Break-Before-Make Switching:** The internal logic ensures a break-before-make switching action. This guarantees that the existing connection is fully broken before a new one is established, preventing momentary shorting between different source channels.
**Application Spectrum**
The combination of its electrical characteristics makes the ADG408BRU incredibly versatile. Its primary applications include:
* **Data Acquisition Systems (DAQ):** Multiplexing multiple sensor inputs into a single analog-to-digital converter (ADC).
* **Audio and Video Signal Routing:** Switching between different audio/video sources.
* **Automated Test Equipment (ATE):** Directing signals and stimuli to various device-under-test (DUT) pins.
* **Communication Systems:** Antenna and filter bank switching.
* **Battery-Powered Systems:** Its low power consumption is essential for extending operational life.
**Package and Robustness**
The "RU" suffix in ADG408BRU denotes a 16-lead TSSOP (Thin Shrink Small Outline Package). This compact package is ideal for space-constrained PCB designs. The device is specified to operate over the **industrial temperature range (-40°C to +85°C)**, ensuring reliable performance in harsh environments.
ICGOOODFIND: The ADG408BRU stands out as a robust and highly reliable solution for precision analog signal routing. Its optimal blend of **low on-resistance, minimal power consumption, and high integration** in a small package makes it an excellent choice for designers seeking to enhance performance and reduce board space in complex electronic systems.
**Keywords:** CMOS Analog Multiplexer, Low On-Resistance, Low Power Dissipation, Break-Before-Make, High Channel Isolation.
