The term **"8-2-R"** typically refers to a specific type of **Resistor Network** or **Resistor Array**, often found in a Single In-line Package (SIP). In electronic component nomenclature, this string of characters defines the physical layout, the number of pins, and the internal configuration of the resistors. --- ### 1. Breakdown of the Part Number In the context of common manufacturers like Bourns or CTS, the code "8-2-R" is interpreted as follows: | Segment | Meaning | Description | | :--- | :--- | :--- | | **8** | **Pin Count** | The component has a total of 8 physical pins. | | **2** | **Circuit Type** | Defines how the resistors are wired internally (Isolated). | | **R** | **Resistance Code** | Indicates the component is a Resistor (often followed by a value). | --- ### 2. Internal Circuit Configuration (Type "2") The "2" in 8-2-R is the most critical part for a circuit designer. It signifies an **Isolated Resistor Network**. * **Isolated Layout:** In an 8-pin package with a "2" configuration, there are **4 independent resistors**. * **Pinout:** * Resistor 1: Pins 1 and 2 * Resistor 2: Pins 3 and 4 * Resistor 3: Pins 5 and 6 * Resistor 4: Pins 7 and 8 * **Advantage:** There is no common terminal. Each resistor is electrically isolated from the others, allowing them to be used in different parts of a circuit. --- ### 3. Technical Specifications While the specific resistance (e.g., 10k ohms) usually follows the "R" (like 8-2-103R), the general characteristics of these parts are: * **Package Type:** SIP (Single In-line Package). * **Power Rating:** Typically 125mW to 250mW per resistor. * **Tolerance:** Usually ±2% or ±5%. * **Temperature Coefficient:** Often ±100 ppm/°C. --- ### 4. Common Applications These arrays are used to save PCB space compared to using individual discrete resistors. 1. **Line Termination:** Terminating data lines to prevent signal reflection. 2. **LED Current Limiting:** Providing the same resistance to multiple LED segments in a display. 3. **Gain Setting:** Used in operational amplifier circuits where matched resistance is required. 4. **Pull-up/Pull-down:** Though "Type 1" (Common Bus) is more common for this, "Type 2" is used when different voltage rails are involved. --- ### 5. Comparison: Type 1 vs. Type 2 | Feature | Type 1 (Bussed) | Type 2 (Isolated) | | :--- | :--- | :--- | | **Common Pin** | Yes (usually Pin 1) | No (Independent pins) | | **Resistor Count** | $Pins - 1$ (7 resistors in an 8-pin) | $Pins / 2$ (4 resistors in an 8-pin) | | **Best For** | Pull-up networks | Signal matching / Independent paths |