The **2SC2248** (often abbreviated as **C2248**) is a Silicon NPN epitaxial planar transistor designed primarily for high-frequency applications, specifically in the VHF (Very High Frequency) range. Below is a detailed breakdown of its specifications, pinout, and typical use cases. --- ## 1. Key Technical Specifications The C2248 is optimized for low-noise amplification and oscillation. | Parameter | Symbol | Maximum Rating | | :--- | :--- | :--- | | **Collector-Base Voltage** | $V_{CBO}$ | 40 V | | **Collector-Emitter Voltage** | $V_{CEO}$ | 30 V | | **Emitter-Base Voltage** | $V_{EBO}$ | 4 V | | **Collector Current** | $I_C$ | 50 mA | | **Collector Power Dissipation** | $P_C$ | 250 mW | | **Transition Frequency** | $f_T$ | 600 MHz (Typical) | | **DC Current Gain** | $h_{FE}$ | 40 to 200 | --- ## 2. Pin Configuration The C2248 usually comes in a **TO-92** plastic package. When looking at the flat side with the pins pointing down, the configuration is as follows: | Pin Number | Name | Function | | :--- | :--- | :--- | | 1 | **Emitter** | Current exits the transistor | | 2 | **Collector** | Current enters the transistor | | 3 | **Base** | Controls the transistor bias | --- ## 3. Applications and Characteristics Because of its high transition frequency ($f_T$) and low noise figure, the C2248 is commonly found in RF (Radio Frequency) circuits. ### Common Uses: * **VHF Tuners:** Used in television and FM radio receivers to amplify incoming signals. * **Local Oscillators:** Integrated into mixing circuits to generate stable high-frequency signals. * **RF Amplifiers:** Small signal amplification in wireless communication devices. * **Signal Buffers:** Used to isolate stages in high-frequency signal processing. ### Performance Highlights: * **Low Capacitance:** It features low collector output capacitance ($C_{ob}$), which is essential for maintaining stability at high frequencies. * **High Gain-Bandwidth Product:** The 600 MHz rating allows it to operate effectively well into the upper VHF band. --- ## 4. Equivalent / Replacement Parts If the C2248 is unavailable, the following transistors are often used as functional equivalents (though pinouts should always be verified): * **2SC1923** * **2SC930** * **BF199** (General high-frequency NPN) * **MPSH10**