### Overview of the 2SC941-R Transistor The **2SC941-R** is a classic NPN epitaxial silicon transistor designed primarily for **High-Frequency (HF)** applications. It was widely used in radio frequency (RF) amplification, mixing, and oscillation stages in older consumer electronics, such as AM/FM radios and communication equipment. --- ### 1. Key Technical Specifications The "R" suffix typically denotes the **hFE (DC Current Gain)** classification, ensuring specific performance characteristics within a defined range. | Parameter | Symbol | Value | Unit | | :--- | :--- | :--- | :--- | | **Type** | - | NPN | - | | **Collector-Base Voltage** | $V_{CBO}$ | 30 | V | | **Collector-Emitter Voltage** | $V_{CEO}$ | 25 | V | | **Emitter-Base Voltage** | $V_{EBO}$ | 5 | V | | **Collector Current** | $I_C$ | 50 | mA | | **Collector Dissipation** | $P_C$ | 200 | mW | | **Transition Frequency** | $f_T$ | 100 - 250 | MHz | | **DC Current Gain (hFE)** | $h_{FE}$ | 40 - 80 (R Class) | - | --- ### 2. Pin Configuration (TO-92 Package) The 2SC941-R usually comes in a standard **TO-92** plastic package. Looking at the flat side with leads pointing down, the pinout is generally as follows: 1. **Emitter (E)** 2. **Collector (C)** 3. **Base (B)** > *Note: Always verify with a multimeter or specific manufacturer datasheet, as some regional variants may swap pins.* --- ### 3. Application Areas Due to its high transition frequency ($f_T$) and low noise profile, the 2SC941-R is suited for: * **RF Amplifiers:** Small signal amplification in radio receivers. * **Oscillators:** Local oscillator circuits for frequency tuning. * **Mixers:** Combining signals in superheterodyne receivers. * **High-Speed Switching:** Low-current logic switching applications. --- ### 4. Equivalent and Replacement Parts If you are looking for a modern replacement for the 2SC941-R, consider the following transistors (though you must verify pinouts as they may differ): * **2SC1815:** A very common NPN transistor (general purpose). * **2SC945:** Similar characteristics and often used in similar circuits. * **KSC945:** Fairchild/ON Semi equivalent. * **BC547:** A common European alternative (Note: Pinout is usually C-B-E). ---