## VS-25TTS12FPPBF Overview The **VS-25TTS12FPPBF** is a high-voltage Phase Control Thyristor (SCR - Silicon Controlled Rectifier) designed for medium power switching applications. It is manufactured by Vishay and is part of the "TO-220 FULL-PAK" series, which provides electrical isolation between the internal parts and the external heatsink. --- ### Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Component Type** | Thyristor (SCR) | | **Package** | TO-220 FULL-PAK (Isolated) | | **Max. RMS On-State Current ($I_{T(RMS)}$)** | 25 A | | **Max. Peak Repetitive Reverse Voltage ($V_{RRM}$)** | 1200 V | | **Max. Peak Non-Repetitive Surge Current ($I_{TSM}$)** | 350 A | | **Max. Gate Trigger Current ($I_{GT}$)** | 45 mA | | **Isolation Voltage ($V_{ISOL}$)** | 2500 V (RMS) | --- ### Electronic Characteristics & Functions #### 1. Phase Control This SCR is specifically designed for **Phase Control**. This means it is optimized for AC power regulation by triggering the gate at specific points in the AC cycle to control the amount of power delivered to a load. #### 2. Fully Isolated Package (FULL-PAK) The "FPPBF" suffix indicates the **TO-220 FULL-PAK**. Unlike standard TO-220 packages where the metal tab is connected to the Anode, this package is completely encapsulated in plastic. * **Benefit:** It provides 2500V RMS isolation, allowing the device to be mounted directly to a common heatsink without needing an external mica insulator. #### 3. High Voltage Rating With a **1200V** rating, it is suitable for industrial applications running on standard 230V to 480V AC lines, providing a significant safety margin against voltage spikes and transients. --- ### Common Applications * **Input Rectification:** Soft start circuits for power supplies. * **Motor Control:** Variable speed drives and AC motor starters. * **Heating Controls:** Precise temperature regulation via phase angle control. * **UPS Systems:** Static switching and battery chargers. --- ### Pin Configuration In a standard TO-220 package for an SCR: 1. **Cathode (K):** The output terminal. 2. **Anode (A):** The input terminal. 3. **Gate (G):** The control terminal used to trigger the device into conduction.