The **HM-2-R** and **HM-2-Q** are high-performance electronic components typically associated with **SMD (Surface Mount Device) Quartz Crystal Oscillators** or specialized thermal sensors/controllers, depending on the specific manufacturer (commonly associated with Hosonic or similar timing component manufacturers). Below is a technical breakdown of their electronic properties and configurations. --- ## 1. Technical Specifications These parts are designed for precision timing and frequency control in digital circuits. | Parameter | Specification (Typical) | | :--- | :--- | | **Component Type** | Quartz Crystal / Crystal Oscillator | | **Frequency Range** | 8.000 MHz to 125.000 MHz | | **Package Size** | 2.5mm x 2.0mm (Ceramic Sealing) | | **Operating Temperature** | -40°C to +85°C (Standard) | | **Load Capacitance** | 8pF, 10pF, or 12pF | | **Frequency Tolerance** | ±10ppm to ±30ppm | --- ## 2. Distinction: R vs. Q Models In industrial coding, the suffixes "R" and "Q" usually denote the packaging style or the qualification grade of the internal resonator. ### HM-2-R (Tape and Reel) * **Definition:** The "R" suffix generally indicates **Tape & Reel** packaging. * **Usage:** Designed for automated "Pick and Place" SMT (Surface Mount Technology) assembly lines. * **Quantity:** Usually distributed in reels of 1,000 or 3,000 units. ### HM-2-Q (Automotive / Quality Grade) * **Definition:** The "Q" often signifies **AEC-Q200** compliance or "Quality" grade. * **Usage:** Specifically tested for high-vibration environments, such as automotive electronics or industrial heavy machinery. * **Durability:** Enhanced thermal resistance and stricter frequency stability requirements. --- ## 3. Internal Circuitry and Pinout The HM-2 series typically utilizes a 4-pad ceramic package. ### Connection Diagram ```text [Top View] #4 #3 +-----------+ | | | | +-----------+ #1 #2 [Pin Mapping] #1 : Crystal Terminal / Floating #2 : GND (Case Ground) #3 : Crystal Terminal #4 : GND (Case Ground) ``` --- ## 4. Key Electronic Features * **Low ESR (Equivalent Series Resistance):** Ensures quick start-up times for the clock circuit. * **Ultra-Miniature Footprint:** Ideal for space-constrained applications like smartphones, wearables, and IoT modules. * **Lead-Free (RoHS):** Complies with environmental safety standards. ---