The **FST3384WM** is a high-performance CMOS 10-bit bus switch. It is primarily used to provide high-speed switching and low-resistance connectivity between two buses without adding significant propagation delay or generating additional ground bounce noise. --- ### 1. Key Technical Specifications The following table summarizes the primary electrical characteristics of the FST3384WM: | Parameter | Specification | | :--- | :--- | | **Logic Type** | 10-Bit Bus Switch | | **Configuration** | Two 5-bit channels (1A-5A to 1B-5B) | | **Operating Voltage ($V_{CC}$)** | 4.0V to 5.5V | | **On-Resistance ($R_{ON}$)** | 4Ω (Typical) | | **Propagation Delay** | < 0.25 ns | | **Control Inputs** | Two Output Enables ($\overline{OE}_1, \overline{OE}_2$) | | **Package Type** | SOIC-24 (Wide Body) | --- ### 2. Functional Description The device consists of ten NMOS pass transistors. It is organized as two independent 5-bit switches. * **Switching Mechanism:** When the Output Enable ($\overline{OE}$) pin is **LOW**, the switch is closed, allowing bi-directional data flow between Port A and Port B. * **Isolation:** When $\overline{OE}$ is **HIGH**, the switch is open, creating a high-impedance (Hi-Z) state between the ports, effectively isolating the buses. * **Zero Delay:** Because it acts as a low-resistance wire when active, it introduces negligible timing skew, making it ideal for high-speed memory interleaving. --- ### 3. Pin Configuration (SOIC-24) Below is a simplified representation of the pinout: | Pin Number | Name | Function | | :--- | :--- | :--- | | 1, 13 | $\overline{OE}_1, \overline{OE}_2$ | Active Low Output Enables | | 2-6, 15-19 | 1A - 10A | Port A Inputs/Outputs | | 7-11, 20-24 | 1B - 10B | Port B Inputs/Outputs | | 12 | GND | Ground | | 24 | $V_{CC}$ | Power Supply | --- ### 4. Typical Applications The FST3384WM is commonly found in digital systems requiring efficient signal routing: 1. **Memory Interleaving:** Switching between different banks of SDRAM. 2. **Bus Isolation:** Protecting sensitive components from bus noise or voltage spikes when not in use. 3. **Voltage Translation:** When operated at specific voltages, it can facilitate 5V to 3.3V signal level shifting. 4. **Hot-Swap Applications:** Allowing cards to be inserted into a backplane without crashing the active bus.