The part number **I640-63BC8O2-155.520** refers to a high-precision **Voltage Controlled Crystal Oscillator (VCXO)**, typically manufactured by companies like ILSI or MMD (often utilized in telecommunications and high-speed networking). --- ### Part Number Decomposition To understand the electronic capabilities, we can break down the coding structure: | Segment | Meaning | Specification | | :--- | :--- | :--- | | **I640** | Series/Package | High-stability VCXO series | | **63** | Operating Voltage | Typically **3.3V DC** | | **B** | Operating Temperature | Usually **-20°C to +70°C** (Industrial/Commercial) | | **C** | Frequency Stability | Often **±50 ppm** or better | | **8** | Pulling Range | Minimum pulling range (e.g., **±80 ppm**) | | **O2** | Output Type | **LVPECL** (Low-Voltage Positive Emitter-Coupled Logic) | | **155.520** | Nominal Frequency | **155.520 MHz** | --- ### Technical Specifications This component is designed for timing applications that require high frequency and low jitter. #### 1. Frequency (155.520 MHz) This specific frequency is the standard for **SONET/SDH** (OC-3) networking. It is a critical clock frequency used in fiber-optic communication systems. #### 2. Output Logic (LVPECL) * **Signaling:** Differential (Two complementary output lines). * **Advantage:** Provides excellent noise immunity and very fast switching speeds, which is necessary for frequencies above 100 MHz. * **Termination:** Requires specific 50-ohm termination to $V_{cc} - 2V$. #### 3. Control Voltage (VCXO Function) The "VC" in VCXO means the output frequency can be "steered" or adjusted slightly by applying a DC voltage to a control pin. This is used for: * Phase-Locked Loops (PLL). * Frequency synchronization between two different clock domains. #### 4. Physical Characteristics * **Package Size:** Usually a surface-mount device (SMD), common sizes are 5x7mm or 3.2x5mm. * **Pinout:** Typically 6-pin configuration (V-control, Enable/Disable, Ground, Output, Complementary Output, Vcc). --- ### Common Applications Due to its precision and standard frequency, this part is found in: 1. **Optical Networking:** SONET/SDH, Gigabit Ethernet. 2. **Base Stations:** LTE/5G cellular infrastructure. 3. **Data Centers:** High-speed switches and routers. 4. **Test Equipment:** Signal generators and frequency counters.