## CSTCW24M5X51-R0: Technical Overview The **CSTCW24M5X51-R0** is a surface-mount (SMD) ceramic resonator produced by **Murata Manufacturing**. It is part of the **CERALOCK®** product line, specifically the small-cap chip type. These components are used as a frequency reference in microcontroller units (MCUs) and other digital circuits. --- ### 1. Key Technical Specifications | Parameter | Specification | |:---|:---| | **Frequency** | 24.5000 MHz | | **Frequency Tolerance** | ±0.5% | | **Operating Temperature** | -20°C to +80°C | | **Built-in Capacitance** | Yes (Built-in load capacitors) | | **Capacitance Value** | 5 pF (Typical) | | **Mounting Type** | Surface Mount (SMD) | | **Package Size** | 2.5 x 2.0 mm (W x L) | | **Frequency Shift by Temp** | ±0.2% (Typical) | --- ### 2. Internal Structure and Design Unlike simple 2-pin crystals, the CSTCW series features a **3-pin design** because it includes built-in load capacitors. 1. **Input Pin:** Connects to the XTAL_IN of the MCU. 2. **GND Pin (Center):** Connects to the system ground. 3. **Output Pin:** Connects to the XTAL_OUT of the MCU. **Benefits of this design:** * **Space Saving:** No need for external capacitors on the PCB. * **Cost Reduction:** Reduces the total Bill of Materials (BOM) count. * **Stability:** Built-in capacitors are matched to the ceramic element for reliable oscillation. --- ### 3. Comparison: Ceramic Resonator vs. Quartz Crystal | Feature | Ceramic Resonator (CSTCW) | Quartz Crystal | |:---|:---|:---| | **Accuracy** | Moderate (±0.5%) | High (±0.001% - ±0.01%) | | **Start-up Time** | Very Fast | Slower | | **Cost** | Low | Higher | | **Durability** | High (Shock resistant) | Fragile | | **Best Use Case** | MCUs, USB, Consumer Electronics | Real-time Clocks, RF Communication | --- ### 4. Typical Application Circuit The following represents how the part is integrated into a standard microcontroller circuit: ```text Microcontroller +----------------+ | | | [XTAL_IN]----+-------[Pin 1] | | | | | [CSTCW24M5X51-R0] | | | | [GND]------+-------[Pin 2] (Center Ground) | | | | [XTAL_OUT]---+-------[Pin 3] | | +----------------+ ``` --- ### 5. Part Number Breakdown * **CSTCW**: Series name (Small-cap chip type). * **24M5**: Frequency (24.5 MHz). * **X**: Design/Thickness code. * **51**: Internal load capacitance code (5 pF). * **-R0**: Packaging code (Plastic tape & reel, 3000 pcs/reel).