The **SFSKA4M50CF00-R3** is a surface-mount (SMD) ceramic filter manufactured by **Murata Electronics**. It belongs to the **SFECV/SFVKA** series, specifically designed for use in intermediate frequency (IF) stages of FM receivers. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Center Frequency (fo)** | 4.500 MHz | | **Bandwidth (3dB)** | ± 60 kHz min. | | **Insertion Loss** | 6.0 dB max. | | **Stop Band Attenuation** | 40 dB min. (at fo ± 1.0 MHz) | | **Input/Output Impedance** | 1000 Ω | | **Operating Temperature** | -20°C to +80°C | | **Mounting Type** | Surface Mount (SMD) | --- ### 2. Functional Description This component is a **Ceramic Filter**. Its primary job is to provide selectivity in an electronic circuit by allowing a specific band of frequencies to pass through while blocking unwanted noise or adjacent channel interference. #### Internal Composition: * **Piezoelectric Material:** It utilizes the mechanical vibration of a ceramic substrate to filter electrical signals. * **Three-terminal Structure:** Usually consists of an Input, Output, and Ground terminal. --- ### 3. Common Applications Due to its 4.5 MHz center frequency, this part is predominantly used in: 1. **TV Sound IF:** Extracting the audio carrier from a television signal. 2. **FM Radio Receivers:** Filtering the intermediate frequency for signal processing. 3. **Communication Equipment:** Narrow-band signal filtering in wireless devices. --- ### 4. Part Number Breakdown (Nomenclature) * **SF:** Ceramic Filter * **KA:** Series Code (High selectivity/Small size) * **4M50:** Center Frequency (4.50 MHz) * **CF00:** Design/Characteristic Code * **R3:** Packaging (usually 3,000 pieces per reel) --- ### 5. Circuit Integration (Typical) ```mermaid graph LR A[Mixer Output] --> B[SFSKA4M50CF00] B --> C[FM Demodulator/IC] G[(Ground)] --- B ```