Based on the part number provided, this component belongs to the **I641 Series** of high-performance crystal oscillators, typically manufactured by companies like ILSI (now part of Abracon) or similar frequency control specialists. --- ### 1. Part Number Breakdown The alphanumeric string follows a specific configuration logic: | Segment | Code | Description | | :--- | :--- | :--- | | **Series** | `I641` | SMD Quartz Crystal Oscillator (typically 5x7mm or 3.2x5mm) | | **Voltage** | `61` | Usually indicates **3.3V DC** supply voltage | | **Output Type** | `AC` | **LVPECL** (Low-Voltage Positive Emitter-Coupled Logic) | | **Stability** | `8O2` | Stability/Temperature code (e.g., ±50ppm or ±25ppm over -40°C to +85°C) | | **Frequency** | `155.520` | Operating frequency of **155.520 MHz** | --- ### 2. Key Technical Specifications This part is a precision timing component designed for high-speed data applications. * **Frequency:** 155.520 MHz (Standard frequency for SONET/SDH/Optical networking). * **Signal Type (LVPECL):** This is a differential signaling standard. It provides high-speed switching and excellent noise immunity, which is critical for high-frequency clocking. * **Package Form Factor:** Typically a 6-pad Ceramic Surface Mount Device (SMD). * **Phase Jitter:** These oscillators are "Low Jitter" components, usually rated sub-1ps (picosecond), ensuring stable data transmission in telecommunications. --- ### 3. Common Applications Due to its specific frequency (155.520 MHz) and differential output, this part is commonly used in: 1. **Fiber Optics:** Clock generation for OC-3 and OC-12 SONET/SDH systems. 2. **Networking:** High-speed Ethernet switches and routers. 3. **Data Storage:** Fiber Channel interfaces. 4. **Telecommunications:** Base stations and backhaul equipment. --- ### 4. Connection Pinout (Typical) Most I641 LVPECL oscillators follow this standard 6-pin configuration: | Pin | Function | Description | | :--- | :--- | :--- | | 1 | OE or NC | Output Enable or No Connect | | 2 | NC | No Connect | | 3 | GND | Ground | | 4 | Output | Positive Output Signal | | 5 | Output Comp | Complementary (Negative) Output Signal | | 6 | Vdd | Supply Voltage (+3.3V) | ---