The **CFWKA450KEFA-R0** is a specific type of **Ceramic Filter** manufactured by **Murata Electronics**. It is designed primarily for use in the intermediate frequency (IF) stages of communication equipment, such as AM/FM radios and telecommunication receivers. ### 1. Component Overview The CFWKA series belongs to the family of **piezoelectric filters**. These components use the mechanical vibrations of ceramic elements to filter out unwanted frequencies while allowing a specific band of frequencies to pass through. | Feature | Specification | | :--- | :--- | | **Component Type** | Ceramic Filter (Ladder Type) | | **Manufacturer** | Murata Electronics | | **Center Frequency** | 450 kHz | | **Mounting Type** | Surface Mount Device (SMD) | | **Primary Application** | AM Narrow-band communication | --- ### 2. Technical Specifications This part is characterized by its "ladder" construction, which provides high selectivity and steep attenuation curves. | Parameter | Value (Typical) | | :--- | :--- | | **Center Frequency ($f_o$)** | 450 kHz | | **3dB Bandwidth** | ±7.5 kHz min. | | **6dB Bandwidth** | ±10.0 kHz min. | | **Stop Band Attenuation** | 50 dB min. (at $f_o$ ±100 kHz) | | **Insertion Loss** | 4.0 dB max. | | **Input/Output Impedance** | 1500 $\Omega$ | --- ### 3. Key Characteristics * **High Selectivity:** Due to the internal "ladder" arrangement of ceramic resonators, it can sharply distinguish between the desired signal and adjacent channel interference. * **Miniaturization:** The "KA" suffix indicates a specific small-form factor SMD package, making it suitable for high-density circuit boards in portable devices. * **Stability:** Ceramic filters are preferred over LC (Inductor-Capacitor) filters because they offer better temperature stability and do not require manual tuning during production. --- ### 4. Typical Circuit Application In a superheterodyne receiver, the CFWKA450KEFA-R0 is placed after the mixer stage. Its role is to isolate the **450 kHz Intermediate Frequency**. ```mermaid graph LR A[Antenna] --> B[RF Amp] B --> C[Mixer] D[Local Osc] --> C C --> E{Ceramic Filter} E --> F[IF Amp / Demodulator] ``` --- ### 5. Part Number Breakdown * **CFW**: Ceramic Filter for Communication (Ladder Type). * **KA**: Package style/series (SMD). * **450**: Nominal center frequency in kHz. * **KEFA**: Bandwidth and specific electrical characteristic code. * **R0**: Packaging code (usually refers to Tape and Reel).