The **MH22FCG-R** is a specialized high-frequency, high-stability **Oven Controlled Crystal Oscillator (OCXO)** manufactured by Mercury Electronic. These components are primarily used in telecommunications and precision timing equipment where frequency stability against temperature fluctuations is critical. --- ### 1. Technical Specifications Below are the primary electronic characteristics typical for the MH22 series: | Parameter | Specification | | :--- | :--- | | **Output Type** | CMOS / TTL | | **Frequency Range** | Usually 10.000 MHz to 100.000 MHz | | **Supply Voltage (Vcc)** | +5.0V or +3.3V (Model dependent) | | **Frequency Stability** | ±0.01 ppm to ±0.1 ppm (Over Temp) | | **Operating Temperature** | -40°C to +85°C (Industrial Grade) | | **Package Style** | Through-hole (DIP-14 equivalent footprint) | | **Power Consumption** | ~3.0W (Warm-up), ~1.2W (Steady state) | --- ### 2. Core Electronic Components An OCXO like the MH22FCG-R is not a simple crystal; it is a complex circuit housed in a metal casing: 1. **SC-Cut or AT-Cut Crystal:** The "heart" of the unit. It vibrates at a specific frequency when voltage is applied. 2. **Heating Element:** A resistive heater that warms the internal chamber to a specific "turn-over" temperature (usually around 75°C to 85°C). 3. **Temperature Sensor (Thermistor):** Monitors the internal temperature of the crystal chamber constantly. 4. **Control Loop (PID Controller):** An analog or digital circuit that adjusts the heater power to keep the internal temperature perfectly stable, regardless of the outside environment. 5. **Voltage Regulator:** Ensures that internal oscillations are not affected by fluctuations in the input power supply. --- ### 3. Pin Configuration Standard layout for the MH22 series (DIP-14/4-pin style): | Pin Number | Function | Description | | :--- | :--- | :--- | | **1** | Vc / NC | Voltage Control (for fine-tuning) or No Connection | | **7** | GND | Ground / Case Connection | | **8** | Output | RF Output signal (CMOS Square Wave) | | **14** | Vcc | Positive Power Supply | --- ### 4. Key Applications Because of its high stability and low "phase noise," this part is used in: * **Base Stations:** Synchronizing timing for 4G/5G cellular networks. * **Test Equipment:** Providing a reference clock for frequency counters and synthesizers. * **Satellite Communications:** Maintaining lock-on signals for ground stations. * **Broadcasting:** Digital video/audio sync.