The **FCR-C4W-R/Q** refers to a specific type of **Ceramic Resonator** manufactured by companies like Murata or Kyocera. These components are used in electronic circuits to generate a stable clock signal or frequency reference for microcontrollers and integrated circuits. --- ## 1. Technical Specifications The "C4W" series generally denotes the physical form factor and frequency range, while the suffixes (R/Q) indicate packaging or specific performance tolerances. | Parameter | Typical Value / Range | | :--- | :--- | | **Component Type** | Ceramic Resonator | | **Frequency Range** | 4.00 MHz to 8.00 MHz (Common) | | **Frequency Tolerance** | ±0.5% | | **Load Capacitance** | Built-in (typically 15pF to 33pF) | | **Temperature Range** | -20°C to +80°C | | **Mounting Type** | Through-hole (SIP 3-pin) | --- ## 2. Key Electronic Features ### A. Built-in Load Capacitors Unlike traditional quartz crystals that require two external capacitors to oscillate, the FCR-C4W-R/Q is a **3-pin device**. * **Pin 1:** Input (Oscillator In) * **Pin 2:** Ground (GND) * **Pin 3:** Output (Oscillator Out) The internal capacitors are connected between Pin 1-GND and Pin 3-GND, reducing PCB space and component count. ### B. Material Composition It utilizes the **piezoelectric effect** of polycrystalline ceramics (usually Lead Zirconate Titanate). When an electrical signal is applied, the ceramic vibrates mechanically at a specific resonant frequency. ### C. Frequency Stability While more stable than a standard RC (Resistor-Capacitor) oscillator, ceramic resonators are **less precise** than quartz crystals. They are ideal for applications where a small frequency drift is acceptable, such as: * Remote controls * Household appliances (Washing machines, Microwaves) * Toys and low-speed USB peripherals --- ## 3. Circuit Implementation To use this part, it is typically connected to the `XTAL1` and `XTAL2` pins of a microcontroller. ```cpp // Example: Conceptual Wiring [MCU] [FCR-C4W-R/Q] Pin: XTAL1 <------> Pin 1 (Input) Pin: GND <------> Pin 2 (Ground) Pin: XTAL2 <------> Pin 3 (Output) ``` --- ## 4. Part Number Breakdown (Suffixes) * **R/Q:** Usually refers to the packaging style. * **R:** Often denotes "Taped" or "Reel" for automated insertion. * **Q:** Often denotes "Bulk" packaging in plastic bags. * **C4W:** Represents the structural design (3-pin SIP, wash-resistant coating).