The **2SC3356** (often marked with the code **R24**) is a NPN silicon epitaxial transistor designed specifically for low-noise, high-gain amplification at high frequencies. It is a staple component in RF (Radio Frequency) engineering. --- ## 1. Key Specifications The 2SC3356 is optimized for the VHF, UHF, and CATV frequency bands. Below are the absolute maximum ratings and electrical characteristics: | Parameter | Symbol | Value | Unit | | :--- | :--- | :--- | :--- | | **Collector to Base Voltage** | $V_{CBO}$ | 20 | V | | **Collector to Emitter Voltage** | $V_{CEO}$ | 12 | V | | **Emitter to Base Voltage** | $V_{EBO}$ | 3.0 | V | | **Collector Current** | $I_C$ | 100 | mA | | **Total Power Dissipation** | $P_{tot}$ | 200 | mW | | **Gain Bandwidth Product** | $f_T$ | 7.0 | GHz (typ) | | **Noise Figure** | $NF$ | 1.1 | dB (at 1GHz) | --- ## 2. The "R24" Marking The "R24" printed on the SOT-23 package identifies the specific **hFE (DC Current Gain) classification**. Manufacturers use these codes because the physical space on the transistor is too small for the full part number. * **R24 Ranking:** Typically represents an hFE range of **40 to 120** or **50 to 100** (depending on the specific manufacturer datasheet like NEC/Renesas). * **Package Type:** Usually comes in the **SOT-23** surface-mount package. --- ## 3. Core Features * **High Gain Bandwidth ($f_T$):** At 7 GHz, this transistor can handle signals well into the gigahertz range without significant gain loss. * **Low Noise Figure:** With an NF of 1.1 dB, it is excellent for the first stage of a receiver where signal-to-noise ratio is critical. * **Large Dynamic Range:** It maintains linearity even when handling slightly higher signal levels compared to smaller signal transistors. --- ## 4. Typical Applications The 2SC3356-R24 is commonly found in: 1. **LNA (Low Noise Amplifiers):** Used in satellite receivers and DIY radio projects. 2. **OSC (Oscillators):** Used as a local oscillator in RF tuners. 3. **CATV Amplifiers:** High-frequency cable television distribution. 4. **Wireless Communication:** Pagers, cordless phones, and RF remote controls. --- ## 5. Pinout Configuration (SOT-23) ```text (3) Collector | +---+---+ | R24 | +---+---+ | | (1) Base (2) Emitter ``` ---