The **FS0203G-2-AA3-R** is a specific electronic component belonging to the **Thyristor (SCR - Silicon Controlled Rectifier)** family. It is typically manufactured by companies like Unisonic Technologies (UTC) and is designed for low-power switching and phase control applications. --- ### 1. General Specifications The following table highlights the primary electrical characteristics of the FS0203G-2-AA3-R: | Parameter | Symbol | Value / Rating | | :--- | :--- | :--- | | **Component Type** | SCR | Sensitive Gate Thyristor | | **Repetitive Peak Off-State Voltage** | $V_{DRM}$ | 400V - 600V (typical for 'G' suffix) | | **RMS On-State Current** | $I_{T(RMS)}$ | 0.8A to 1.25A | | **Gate Trigger Current** | $I_{GT}$ | $\le$ 200 µA (Sensitive Gate) | | **Package Type** | SOT-223 | Surface Mount Device (SMD) | | **Operating Temperature** | $T_j$ | -40°C to +125°C | --- ### 2. Pin Configuration (SOT-223) The SOT-223 package is a 4-terminal surface mount package (where the large tab is often internally connected to one of the pins). 1. **Cathode (K):** The terminal through which current exits the device. 2. **Anode (A):** The terminal through which current enters the device (connected to the tab). 3. **Gate (G):** The control terminal used to trigger the device into conduction. --- ### 3. Key Features * **Sensitive Gate:** With an $I_{GT}$ of less than 200 microamps, this device can be triggered directly by low-power microcontrollers or logic integrated circuits without needing an external driver. * **Glass Passivated Chip:** Provides high reliability and stability at high temperatures. * **Surface Mount Design:** Optimized for automated assembly on printed circuit boards (PCBs). --- ### 4. Common Applications Due to its low current rating and high sensitivity, it is commonly used in: * **Ground Fault Circuit Interrupters (GFCI):** Sensing leakage currents to trip a circuit. * **Ignition Circuits:** Small engine or gas appliance ignition. * **Logic Level Interfaces:** Controlling small relays, lamps, or solenoids from digital logic. * **Small Motor Control:** Speed control for tiny fans or household appliances. --- ### 5. Part Number Breakdown (Typical) * **FS:** Series Prefix (Thyristor/SCR). * **02:** Current Rating (approx. 1A - 2A range). * **03:** Specific designator for gate sensitivity. * **G:** Voltage Rating (G usually denotes 400V or 600V). * **AA3:** Package Code (SOT-223). * **R:** Packing Code (Tape and Reel). ---