## Electronic Component Analysis: RSMF3JB33R2 The **RSMF3JB33R2** is a high-performance power resistor manufactured by **Stackpole Electronics**. It belongs to the **RSMF (Miniature Metal Oxide Resistor)** series, which is designed for applications requiring high power in a small form factor compared to standard metal oxide resistors. ### 1. Part Number Breakdown Understanding the nomenclature helps identify the specific characteristics of the component: | Code Segment | Meaning | Specific Value | | :--- | :--- | :--- | | **RSMF** | Series Name | Mini Metal Oxide Leaded Resistor | | **3** | Power Rating | 3 Watts | | **J** | Tolerance | ± 5% | | **B** | Packaging | Bulk | | **33R2** | Resistance Value | 33.2 Ohms | --- ### 2. Technical Specifications The primary electrical and physical characteristics are detailed below: | Parameter | Specification | | :--- | :--- | | **Resistance** | 33.2 $\Omega$ | | **Power Rating** | 3.0 Watts | | **Tolerance** | ± 5% | | **Temperature Coefficient** | ± 200 ppm/°C | | **Voltage Rating (Max)** | 500V | | **Operating Temperature** | -55°C to +200°C | | **Construction** | Metal Oxide Film on Ceramic Core | | **Coating** | Flameproof Silicone Coating | --- ### 3. Key Features and Benefits * **Miniaturization:** The "Mini" designation means it provides a 3W power rating in a package size typically used for 1W or 2W standard resistors. * **Flameproof:** The outer coating is designed to be flameproof (UL94V-0 equivalent), ensuring safety in the event of an overload or failure. * **High Stability:** Metal oxide film technology offers better stability under high temperatures and moisture compared to carbon film resistors. * **Surge Handling:** Excellent pulse-handling capabilities, making it suitable for power supply input stages. --- ### 4. Typical Applications Given its high power density and safety features, this part is commonly found in: 1. **Switching Power Supplies (SMPS):** Used for snubber circuits or current sensing. 2. **Motor Controllers:** Handling start-up surges or braking. 3. **Industrial Controls:** High-wattage pull-up/pull-down or voltage dropping. 4. **Audio Amplifiers:** Used in output stages where high heat dissipation is required. --- ### 5. Mechanical Dimensions (Typical) * **Body Length:** ~15.0 mm * **Body Diameter:** ~5.0 mm * **Lead Diameter:** ~0.8 mm