## Overview of the 2SA1418-R The **2SA1418-R** is a high-speed, high-voltage PNP epitaxial silicon transistor. It is primarily designed for high-definition CRT display video output and high-speed switching applications. The suffix "-R" typically denotes the **hFE (DC Current Gain)** classification rank. --- ### 1. Key Technical Specifications Below are the absolute maximum ratings and electrical characteristics for the 2SA1418-R: | Parameter | Symbol | Rating/Value | | :--- | :--- | :--- | | **Collector-Base Voltage** | $V_{CBO}$ | -180 V | | **Collector-Emitter Voltage** | $V_{CEO}$ | -160 V | | **Emitter-Base Voltage** | $V_{EBO}$ | -5 V | | **Collector Current (DC)** | $I_C$ | -700 mA | | **Collector Current (Pulse)** | $I_{CP}$ | -1.2 A | | **Total Power Dissipation** | $P_C$ | 1 W (Free air) / 10 W ($T_c = 25^\circ C$) | | **DC Current Gain (R-Rank)** | $h_{FE}$ | 100 to 200 | | **Transition Frequency** | $f_T$ | 120 MHz (Typical) | --- ### 2. Physical Characteristics & Package The 2SA1418-R is commonly found in the **TO-126ML** (also known as the MP package) or **TO-225AA** style package. This is a plastic-molded package that allows for heat sink mounting. * **Pinout Configuration:** 1. **Emitter** (E) 2. **Collector** (C) 3. **Base** (B) *(Note: Looking at the labeled front side, pins are usually left-to-right).* --- ### 3. Key Features * **High Breakdown Voltage:** With a $V_{CEO}$ of -160V, it can handle high-voltage spikes and steady-state high voltage requirements. * **Complementary Pair:** The NPN counterpart for the 2SA1418 is the **2SC3648**. * **Low Output Capacitance:** Small $C_{ob}$ (typically around 13 pF) makes it excellent for high-frequency performance. * **Excellent Linearity:** Provides consistent gain across a range of collector currents. --- ### 4. Common Applications * **Video Output Stages:** Used in high-resolution monitors and television sets. * **Switching Regulators:** High-speed switching due to its high $f_T$. * **Audio Amplifiers:** Used in the driver stages of power amplifiers where high voltage rails are present. * **General Purpose High-Voltage Switching:** Controlling loads that exceed standard 50V-100V limits. --- ### 5. Identification of the "R" Suffix In transistors of this series, the letter designates the **DC Current Gain ($h_{FE}$)** range: * **S:** 140 to 280 * **R:** 100 to 200 * **Q:** 70 to 140