The **MCSO2EH** is a high-reliability, high-temperature crystal oscillator designed specifically for extreme environments. It is manufactured by **Microcrystal** (a Swatch Group company) and is widely used in aerospace, down-hole drilling, and harsh industrial applications. --- ### ## Technical Specifications The "EH" suffix typically indicates the high-temperature version of the MCSO2 series. Below are the core electronic characteristics: | Parameter | Specification | | :--- | :--- | | **Frequency Range** | 10 kHz to 225 MHz | | **Supply Voltage (Vdd)** | 2.5V, 3.3V, or 5.0V | | **Operating Temperature** | -55°C to +210°C (Extended range) | | **Output Waveform** | CMOS / HC-MOS | | **Package Size** | 5.0 x 3.2 x 1.3 mm | | **Current Consumption** | Very Low (typically < 5mA depending on frequency) | --- ### ## Key Electronic Components & Design #### 1. The Quartz Crystal The heart of the MCSO2EH is a high-quality quartz resonator. Unlike standard crystals, the MCSO2EH uses a specialized cut and mounting technique to ensure the frequency remains stable even as temperatures exceed 200°C. #### 2. CMOS Integrated Circuit (IC) The internal ASIC (Application-Specific Integrated Circuit) handles: * **Oscillation:** Maintaining the resonant frequency. * **Output Buffering:** Driving the CMOS signal to external circuits. * **Low Power Logic:** Designed to minimize current draw, which reduces self-heating. #### 3. Hermetic Packaging The electronics are housed in a **ceramic package** with a Kovar lid. The interior is vacuum-sealed or filled with inert gas to prevent oxidation of the gold-plated pads and the crystal itself at high temperatures. --- ### ## Operational Features * **High Shock/Vibration Resistance:** The internal mounting is reinforced to withstand the mechanical stresses found in aerospace launches or drilling operations (often up to 20g vibration and 5000g shock). * **Aging:** Designed for low aging rates, ensuring that the frequency does not drift significantly over years of operation. * **Enable/Disable Function:** Most models include a "Tri-state" pin (Pin 1), allowing the output to be turned off to save power without powering down the entire system. --- ### ## Typical Pin Configuration | Pin Number | Function | Description | | :--- | :--- | :--- | | **1** | E/D or NC | Enable/Disable or No Connection | | **2** | GND | Ground | | **3** | Fout | Frequency Output (CMOS) | | **4** | Vdd | Supply Voltage | ---