It appears you are referring to the **R1R-R** marking found on specific electronic components, most commonly **Surface Mount Device (SMD) Resistors** or specific **Power Modules**. Below is a breakdown of what this code typically represents in the electronics industry. --- ## 1. Resistance Code Interpretation In resistor marking systems (BS 1852 or IEC 60062), the letter **"R"** acts as a decimal point. | Marking | Meaning | Ohmic Value | | :--- | :--- | :--- | | **R1** | 0.1 | 0.1 $\Omega$ | | **1R** | 1.0 | 1.0 $\Omega$ | | **R1R** | 0.11 (Rare) | 0.11 $\Omega$ | However, the specific string **"R1R-R"** is often a proprietary part number suffix or a series indicator rather than a standard value code. --- ## 2. Common Component Associations In most professional contexts, "R1R-R" refers to one of the following: ### A. Resistor Network / Termination It is frequently used by manufacturers like **Bourns** or **Vishay** to denote a specific configuration in a resistor network. * **The first 'R':** Often denotes a "Series" or "Bus" layout. * **The '-R':** Typically stands for **RoHS Compliant** (Lead-free). ### B. High-Power Resistors (Chassis Mount) If the part is a large metal-clad component, the "R" suffix often indicates the **Tolerance** or **Reverse polarity** protection in specific module types. ### C. Example Specification Table If we assume a standard 1206 or 2512 SMD Resistor marked with a variation of this code: | Feature | Description | | :--- | :--- | | **Component Type** | Fixed Resistor / Current Sense Resistor | | **Standard Tolerance** | Usually $\pm 1\%$ or $\pm 5\%$ | | **Material** | Thick Film or Metal Strip | | **Compliance** | RoHS / Green (The "-R" suffix) | --- ## 3. How to Verify If you are looking at a physical part on a PCB, use a Multimeter to confirm: 1. **Set to Ohms ($\Omega$):** Measure across the leads. 2. **Expected Reading:** If it is a low-resistance shunt, it should read very close to **0.1 to 1.1 Ohms**. 3. **Open Loop (OL):** If it reads OL, the component is likely blown (common in power supply "R" resistors). ---