## Technical Overview: PLL502-35OC-R The **PLL502-35OC-R** is a high-performance, low-phase-noise **Phase-Locked Loop (PLL) Clock Multiplier** integrated circuit. It is manufactured by Microchip Technology (formerly PhaseLink) and is designed specifically for high-speed clock generation in networking and storage applications. ### 1. General Specifications | Feature | Details | | :--- | :--- | | **Component Type** | PLL Clock Multiplier / Buffer | | **Output Type** | LVCMOS (Low Voltage Complementary Metal Oxide Semiconductor) | | **Frequency Range** | 622.08 MHz (Typical optimized output) | | **Input Range** | 19.44 MHz or 38.88 MHz Crystal/Clock | | **Supply Voltage** | 3.3V (± 10%) | | **Package** | SOP-8 (Small Outline Package, 8-pin) | | **Operating Temp** | 0°C to +70°C (Commercial Grade) | --- ### 2. Functional Components The IC consists of several internal stages that allow it to take a low-frequency reference and convert it into a stable high-frequency clock signal: * **Reference Oscillator:** Accepts a fundamental mode crystal or an external reference clock. * **Phase Detector (PD):** Compares the phase of the input clock to the feedback clock. * **Voltage Controlled Oscillator (VCO):** Generates the high-frequency output based on the error voltage from the phase detector. * **Frequency Multiplier:** Specifically designed to provide multipliers for SONET/SDH frequencies (e.g., 622.08 MHz). ### 3. Pin Configuration (SOP-8) | Pin # | Pin Name | Description | | :--- | :--- | :--- | | 1 | XIN / CLK | Crystal Input or Reference Clock Input | | 2 | XOUT | Crystal Output (Leave floating if using external clock) | | 3 | VDD | Positive Power Supply (3.3V) | | 4 | GND | Ground | | 5 | OE | Output Enable (High = Enable, Low = High Impedance) | | 6 | FSEL | Frequency Select (Configures the multiplication factor) | | 7 | CLK_OUT | Main Clock Output (High Speed) | | 8 | NC / TEST | No Connection or Manufacturer Test Pin | --- ### 4. Key Features and Advantages 1. **Low Jitter:** Optimized for "ultra-low jitter" (typically < 1ps RMS), making it suitable for fiber optics and Gigabit Ethernet. 2. **Pulling Range:** Often supports a wide pulling range if used in a VCXO (Voltage Controlled Crystal Oscillator) configuration. 3. **Space Efficiency:** The SOP-8 footprint is small, reducing PCB real estate requirements. 4. **No External Loop Filter:** The PLL loop filter is integrated on-chip, simplifying the circuit design for the engineer. ### 5. Common Applications * **SONET / SDH:** Clock generation for OC-3, OC-12, and OC-48 systems. * **Networking:** Gigabit Ethernet and Fibre Channel switches. * **Storage:** SAN (Storage Area Network) equipment. * **Data Conversion:** Providing high-stability clocks for ADCs or DACs.