## Overview of ADG508ATCHIPS The **ADG508ATCHIPS** is a high-performance, monolithic CMOS analog multiplexer comprising eight single channels. It is designed using an advanced LC²MOS (Linear Compatible CMOS) process, which provides low power dissipation yet achieves high switching speed and low on-resistance. --- ### 1. Key Technical Specifications The following table summarizes the primary electrical characteristics of the ADG508A series: | Parameter | Specification | | :--- | :--- | | **Configuration** | 8-Channel Single-Ended (8:1) | | **Supply Voltage (Dual)** | ±10.8V to ±16.5V | | **Supply Voltage (Single)** | 12V Typical | | **On-Resistance ($R_{ON}$)** | 300 $\Omega$ (Max) | | **Switching Time ($t_{ON}$/$t_{OFF}$)** | 300 ns / 250 ns | | **Power Dissipation** | 3.2 mW (Max) | | **Package Format** | CHIPS (Bare Die) | --- ### 2. Functional Description The device switches one of eight inputs to a common output ($D$) based on the state of three binary address lines ($A0, A1, A2$) and an Enable ($EN$) input. * **Logic Control:** The address inputs are TTL and CMOS compatible. * **Enable Pin:** When the $EN$ input is logic "Low," all channels are turned off, allowing for easy device expansion (daisy-chaining multiple multiplexers). * **Break-Before-Make:** The device features an inherent break-before-make switching action, which prevents momentary shorting of the input channels during transition. --- ### 3. Electronic Architecture & Components The "CHIPS" designation indicates that the part is supplied as a **bare die**. This is significant for specific high-density or high-reliability electronic assemblies: #### A. The CMOS Structure The part utilizes a combination of P-channel and N-channel MOSFETs in parallel. This configuration ensures: 1. **Rail-to-Rail Signaling:** The input signal range extends to the supply rails. 2. **Constant Resistance:** The $R_{ON}$ remains relatively flat across the full analog signal range. #### B. The Latch-Up Proof Design The LC²MOS construction includes an epitaxial layer that prevents latch-up, a common failure mode in older CMOS devices where high currents flow between power supplies, potentially destroying the part. #### C. Interconnects (Bare Die Features) * **Bond Pads:** Instead of traditional pins, the chip has gold or aluminum bond pads designed for ultrasonic wire bonding. * **Backside:** The back of the die is usually connected to $V_{DD}$ or left floating, depending on the specific assembly instructions provided by Analog Devices. --- ### 4. Typical Applications * **Data Acquisition Systems:** Sequencing multiple sensor signals into a single ADC. * **Communication Systems:** Signal routing and gain control. * **Avionics/Space:** The CHIPS version is often used in Hybrid Microcircuits where space is at a premium. * **Automatic Test Equipment (ATE):** High-speed signal switching.