The **PI3USB14LE** is a high-bandwidth, 2-channel, 4:1 Multiplexer/Demultiplexer (switch) designed specifically for switching USB 2.0 signals. It is manufactured by Diodes Incorporated (formerly Pericom). --- ### ## Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Configuration** | 4-to-1 Differential Mux/Demux | | **Bandwidth** | 815 MHz | | **Operating Voltage (Vcc)** | 3.3V ± 10% | | **On-Resistance (Ron)** | 8Ω (Typical) | | **Package** | 16-pin TSSOP (L) | | **Signal Type** | High-Speed USB 2.0 (480 Mbps) | --- ### ### Core Electronic Functions 1. **Signal Switching (Mux/Demux):** The device allows one differential pair (D+/D-) to be connected to one of four different destinations. Because it is bidirectional, it can act as a **Multiplexer** (4 inputs to 1 output) or a **Demultiplexer** (1 input to 4 outputs). 2. **High Bandwidth (815 MHz):** While USB 2.0 High-Speed operates at 480 Mbps, the switch provides over 800 MHz of bandwidth. This ensures minimal signal distortion and low "jitter," preserving the eye diagram integrity of the data. 3. **Low Crosstalk and Insertion Loss:** The internal architecture is optimized to prevent signal leakage between the four channels (Crosstalk) and to ensure the signal strength doesn't drop significantly as it passes through the switch (Insertion Loss). --- ### ### Pin Configuration and Control Logic The device uses two binary control pins (**S0**, **S1**) and an Enable pin (**En**) to determine which path is active. | En | S1 | S0 | Function | | :--- | :--- | :--- | :--- | | 0 | 0 | 0 | Port 0 Active | | 0 | 0 | 1 | Port 1 Active | | 0 | 1 | 0 | Port 2 Active | | 0 | 1 | 1 | Port 3 Active | | 1 | X | X | Disconnect (Hi-Z State) | --- ### ### Typical Application Use-Cases * **Docking Stations:** Routing a single USB signal from a laptop to multiple external USB ports or peripherals. * **Cell Phones/Tablets:** Switching a single micro-USB or USB-C port between data transfer, charging logic, or audio modes. * **Servers:** Routing management signals to different blades or modules within a rack. --- ### ### Schematic Symbols & Connections When designing a PCB with the PI3USB14LE, keep these electronic best practices in mind: * **Decoupling:** Place a 0.1µF ceramic capacitor as close as possible to the Vcc pin to filter power noise. * **Impedance Matching:** Maintain 90Ω differential impedance on the PCB traces for the D+/D- lines to prevent reflections. * **ESD Protection:** While the chip has internal ESD protection, external TVS diodes are recommended for ports exposed to the outside world.