The **M7R18TAJ-R** is an industrial-grade **Crystal Oscillator** manufactured by **Mercury Electronic**. It is specifically designed for high-precision timing in electronic circuits, utilizing a Surface Mount Device (SMD) form factor. --- ## 1. Technical Specifications The part number follows a specific nomenclature used by Mercury Electronic to define its electrical characteristics. | Parameter | Specification | | :--- | :--- | | **Component Type** | XO (Crystal Oscillator) | | **Frequency Range** | Typically 1.0 MHz to 156.25 MHz (Model specific) | | **Supply Voltage (Vcc)** | 1.8V DC | | **Output Type** | CMOS / HCMOS | | **Frequency Stability** | ±25ppm to ±100ppm (Depending on suffix) | | **Operating Temperature** | -40°C to +85°C (Industrial Grade) | | **Package Size** | 7.0 x 5.0 mm (SMD 4-Pad) | --- ## 2. Key Internal Components The "Electronic Parts" within this single package consist of three main integrated elements: ### A. The Quartz Crystal Blank A high-purity synthetic quartz wafer cut at a specific angle (usually AT-cut). This provides the mechanical resonance required to generate a stable frequency. ### B. The Oscillator IC (ASIC) A specialized Integrated Circuit that performs three functions: 1. **Drive Circuit:** Maintains the vibration of the quartz crystal. 2. **Frequency Divider/Buffer:** Shapes the sine wave from the crystal into a clean square wave (CMOS). 3. **Trimming Circuit:** Adjusts the output to ensure the frequency stays within the specified tolerance. ### C. Ceramic Package & Lid The internal components are housed in a multi-layer ceramic base with a gold-plated Kovar lid, hermetically sealed (usually via seam welding) in a nitrogen atmosphere to prevent oxidation and aging. --- ## 3. Pin Configuration (4-Pad SMD) For PCB layout and integration, the M7R series follows a standard industry pinout: | Pin Number | Function | Description | | :--- | :--- | :--- | | **1** | E/D (Enable/Disable) | High or Open = Output Active; Low = High Impedance | | **2** | GND | Ground / Negative Supply | | **3** | Output | Square wave CMOS output signal | | **4** | Vdd | Positive Power Supply (1.8V) | --- ## 4. Typical Applications Due to its low voltage (1.8V) and stable performance, this part is commonly found in: * **Networking Gear:** Routers and Switches. * **Embedded Systems:** Microcontrollers and FPGAs requiring an external clock. * **Storage Devices:** SSD controllers and Fibre Channel interfaces. * **Mobile Equipment:** Low-power handheld industrial devices.