## Overview of PL502-02HSC-R The **PL502-02HSC-R** is a high-performance, low-phase noise **VCXO (Voltage Controlled Crystal Oscillator)** IC produced by Microchip Technology (formerly PhaseLink). It is specifically designed to work with high-frequency fundamental crystals to provide a very clean clock output. --- ### Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Function** | VCXO (Voltage Controlled Crystal Oscillator) | | **Input Frequency** | 12MHz to 25MHz (Fundamental Crystal) | | **Output Frequency** | Up to 200MHz (Multiplied) | | **Output Type** | CMOS | | **Supply Voltage** | 3.3V (±10%) | | **Operating Temperature** | 0°C to +70°C (Commercial Grade) | | **Package Type** | SOP-8 (Standard Outline Package, 8 pins) | | **Pulling Range** | ±200 ppm (typical) | --- ### Internal Functional Blocks The device consists of several critical electronic stages that allow it to function as a frequency synthesizer: 1. **Crystal Oscillator Core:** Connects to an external crystal at pins `XIN` and `XOUT`. It is optimized for fundamental mode crystals to minimize jitter. 2. **Voltage Control (VC) Circuit:** A control voltage (typically 0V to 3.3V) applied to the `VIN` pin adjusts the capacitance of internal varactors, slightly "pulling" the frequency of the crystal. 3. **Phase-Locked Loop (PLL):** The core of the "H" (High Frequency) version. It uses a low-noise multiplier to scale the crystal frequency (e.g., 25MHz) up to the desired output frequency (e.g., 100MHz or 200MHz). 4. **Output Buffer:** A high-speed CMOS driver that delivers the final clock signal to the rest of the PCB while maintaining sharp rise/fall times. --- ### Pin Configuration (SOP-8) | Pin # | Name | Description | | :--- | :--- | :--- | | 1 | **VIN** | Voltage control input for frequency pulling. | | 2 | **XIN** | Crystal input connection. | | 3 | **GND** | Ground connection. | | 4 | **XOUT** | Crystal output connection. | | 5 | **NC** | No internal connection. | | 6 | **CLK** | CMOS Clock output. | | 7 | **OE** | Output Enable (High = Active; Low = Hi-Z). | | 8 | **VDD** | Power supply (3.3V). | --- ### Common Applications * **Networking:** Gigabit Ethernet, SONET/SDH, and Fibre Channel. * **Video Systems:** High-definition video clocks and Set-Top Boxes. * **Phase-Locked Loops:** Used as a reference clock for jitter cleaning or frequency translation. * **Embedded Systems:** Providing high-speed system clocks from inexpensive low-frequency crystals. ---