The **5ET3-R** refers to a high-performance **Crystal Oscillator (XO)** manufactured by **TXC Corporation**. It belongs to their 5E series of differential output oscillators, commonly used in high-speed networking and telecommunications. --- ### 1. Key Technical Specifications The following table summarizes the primary electronic characteristics of the 5ET3-R series: | Parameter | Specification | | :--- | :--- | | **Output Type** | LVPECL (Low-Voltage Positive Emitter-Coupled Logic) | | **Package Size** | 7.0 x 5.0 x 1.6 mm (SMD Package) | | **Frequency Range** | 13.5 MHz to 220 MHz | | **Supply Voltage (Vdd)** | 2.5V or 3.3V | | **Frequency Stability** | ±25 ppm, ±50 ppm (Typical) | | **Operating Temperature** | -40°C to +85°C (Industrial Grade) | | **Phase Jitter** | < 1 ps (Integrated 12 kHz to 20 MHz) | --- ### 2. Functional Components The 5ET3-R is more than just a crystal; it is an integrated circuit assembly consisting of: * **Quartz Crystal Blank:** The mechanical resonator that provides the base frequency. * **Oscillator IC:** An ASIC that drives the crystal and converts the signal into a differential LVPECL output. * **Voltage Regulator:** Internal circuitry to maintain stability despite minor power supply fluctuations. * **Tri-state Function:** Pin 1 usually supports an "Enable/Disable" function, allowing the output to go into a high-impedance state for power saving or testing. --- ### 3. Application Areas Due to its low jitter and differential signaling (which reduces electromagnetic interference), the 5ET3-R is used in: 1. **Fiber Channel & Ethernet:** 10G, 40G, and 100G networking equipment. 2. **Server Storage:** SAS/SATA interfaces and PCI Express clocks. 3. **Base Stations:** Cellular infrastructure requiring precise timing. 4. **Optical Modules:** SFP+, QSFP, and CFP transceivers. --- ### 4. Pin Configuration (Typical 6-Pin Layout) | Pin # | Function | Description | | :--- | :--- | :--- | | 1 | OE or NC | Output Enable or No Connection | | 2 | NC | No Connection | | 3 | GND | Ground | | 4 | OUT | Positive Output | | 5 | OUTN | Complementary (Negative) Output | | 6 | Vdd | Supply Voltage |