The **SS21VB-R070099** is a high-performance common mode choke coil manufactured by **KEMET** (specifically from their Signal & Power Solutions division). It is primarily used for noise suppression in power supply circuits. --- ### 1. Technical Specifications The following table summarizes the key electrical and physical characteristics of this component: | Parameter | Specification | | :--- | :--- | | **Component Type** | AC Line Filter / Common Mode Choke | | **Series** | SS21VB (Vertical Terminal Type) | | **Rated Current** | 0.7 Amperes (Max) | | **Inductance** | 9.9 mH (Minimum) | | **Rated Voltage** | 250 VAC | | **DC Resistance** | 0.77 $\Omega$ (Per Line) | | **Temperature Rise** | 45 K (Max) | | **Operating Temperature** | -25°C to +120°C | --- ### 2. Physical Design and Construction The "SS" series utilizes a proprietary ferrite core designed to handle high-frequency interference. * **Core Material:** High-permeability manganese-zinc (Mn-Zn) ferrite. * **Form Factor:** Vertical mount (VB suffix). This is ideal for PCB designs where horizontal space is limited but vertical clearance is available. * **Bobbin Structure:** The "R" in the part number often signifies a specific winding or core orientation designed to optimize the magnetic path and reduce stray capacitance. --- ### 3. Key Functions The SS21VB-R070099 performs three main roles in an electronic circuit: 1. **Common Mode Noise Suppression:** It filters out electromagnetic interference (EMI) that travels in the same direction on both the power and neutral lines. 2. **Safety Compliance:** Helps electronic products meet international EMC (Electromagnetic Compatibility) standards like CISPR or FCC. 3. **Signal Integrity:** Prevents high-frequency switching noise from a Switch Mode Power Supply (SMPS) from leaking back into the AC mains. --- ### 4. Typical Applications This component is commonly found in low-to-medium power electronics, including: * **Switch Mode Power Supplies (SMPS):** Used in the input filter stage. * **LED Lighting Drivers:** To prevent flicker and radio interference. * **Home Appliances:** Washing machines, refrigerators, and air conditioners. * **AV Equipment:** Audio amplifiers and television power boards. --- ### 5. Schematic Representation In a circuit diagram, it is represented as two coupled inductors on a single core: ```text AC Input (L) ----( Coil 1 )---- To Rectifier ) ) ) ) (Ferrite Core) AC Input (N) ----( Coil 2 )---- To Rectifier ```