## Overview of ADG3249BRJ-R2 The **ADG3249BRJ-R2** is a high-performance bus switch IC manufactured by Analog Devices. It is specifically designed as a 2-bit, 2:1 multiplexer/demultiplexer that operates at very high speeds with minimal signal distortion. It is commonly used in level translation and high-speed bus switching applications. --- ### Technical Specifications | Parameter | Specification | | :--- | :--- | | **Function** | 2-bit, 2:1 Multiplexer/Demultiplexer | | **Supply Voltage (Vcc)** | 2.3 V to 3.6 V | | **On-Resistance (Ron)** | ~8 $\Omega$ (Typical) | | **Propagation Delay** | < 250 ps (Extremely Low) | | **Package Type** | SOT-23-8 (RJ-8) | | **Operating Temperature** | -40°C to +85°C | | **Control Logic** | LVTTL/CMOS Compatible | --- ### Key Electronic Features 1. **Low On-Resistance ($R_{ON}$):** With a resistance of approximately 8 $\Omega$, the device ensures minimal voltage drop across the switch, which is critical for maintaining signal integrity in high-speed data paths. 2. **Ultra-Low Propagation Delay:** The delay is less than 250 picoseconds. This makes the part "transparent" in the timing budget of high-speed digital circuits. 3. **Bidirectional Operation:** Because it uses a MOSFET switch architecture, data can flow in either direction (from A to B or B to A), allowing it to act as both a multiplexer and a demultiplexer. 4. **Voltage Level Translation:** The ADG3249 is often used for level shifting. For example, it can interface between 3.3 V systems and 2.5 V systems by limiting the output voltage through the supply rail configuration. --- ### Pin Configuration & Functionality The device typically follows a standard 8-lead SOT-23 pinout: * **S (Select):** Determines which input (B1 or B2) is connected to the output (A). * **A1, A2:** Common ports (Output/Input). * **B1, B2:** Switched ports (Input/Output). * **Vcc / GND:** Power supply and ground pins. --- ### Typical Applications * **Bus Isolation:** Isolating a bus segment to reduce capacitive loading. * **Voltage Translation:** Interfacing different logic families (e.g., 3.3V to 1.8V). * **Hot-Plugging:** Protecting circuitry during live insertion of cards or modules. * **Memory Switching:** Routing signals between different memory banks or CPUs. ---