The **FCR-KB-R** is a specific electronic component belonging to the **Piezoelectric Resonator** family, manufactured by **Fujitsu** (and later integrated into the **KDS - Daishinku Corp** product lines). It is primarily used as a frequency control element in microcomputer and microcontroller circuits. --- ### 1. General Specifications The FCR-KB-R series consists of ceramic resonators designed for surface mount (SMT) applications. These parts are used to generate a stable clock signal for ICs. | Parameter | Specification Details | | :--- | :--- | | **Component Type** | Ceramic Resonator | | **Mounting Type** | Surface Mount Device (SMD) | | **Frequency Range** | Typically 4.00 MHz to 20.00 MHz | | **Frequency Tolerance** | ±0.5% (Standard) | | **Operating Temperature** | -20°C to +80°C | | **Built-in Capacitance** | Includes internal load capacitors (3-terminal type) | --- ### 2. Key Electronic Features #### A. Built-in Load Capacitors Unlike traditional 2-pin crystals that require external capacitors (C1 and C2) to oscillate, the **FCR-KB-R** is a **3-terminal device**. * The center pin is connected to the Ground (GND). * This simplifies PCB design, reduces the component count, and saves board space. #### B. Piezoelectric Effect It utilizes the mechanical resonance of a piezoelectric ceramic material (usually Lead Zirconate Titanate). When an electrical signal is applied, the material vibrates at a specific frequency, which is then fed back into the microcontroller's oscillator circuit. #### C. Stability vs. Crystals * **Precision:** It is more precise than an RC (Resistor-Capacitor) oscillator but less precise than a Quartz Crystal. * **Start-up Time:** It offers a much faster start-up time than quartz crystals, which is ideal for power-saving modes in electronics. --- ### 3. Part Number Breakdown (Example) The part numbering system usually follows this logic: | Segment | Meaning | | :--- | :--- | | **FCR** | Fujitsu Ceramic Resonator | | **4.0** | The nominal frequency (e.g., 4.0 MHz) | | **KB** | Series code (SMD, built-in caps) | | **R** | Taping/Packaging (Reel) | --- ### 4. Common Applications Due to its small footprint and integrated capacitors, the FCR-KB-R is found in: 1. **Consumer Electronics:** Remote controls, toys, and small appliances. 2. **Automotive:** Body control modules (non-safety critical) and dashboard displays. 3. **Computer Peripherals:** Keyboards, mice, and USB hubs. ---