## Technical Overview: ST280CH..C Series Thyristor The **ST280CH..C** series consists of phase-control thyristors (Silicon Controlled Rectifiers) manufactured by Vishay (formerly International Rectifier). These are high-power semiconductors designed in a "Hockey Puk" (press-fit) ceramic housing, optimized for industrial power conversion applications. --- ### 1. Key Technical Specifications The ".." in the part number typically denotes the voltage rating (e.g., ST280CH10C means 1000V). | Parameter | Symbol | Typical Value | Unit | | :--- | :--- | :--- | :--- | | **RMS On-State Current** | $I_{T(RMS)}$ | 520 | A | | **Average On-State Current** | $I_{T(AV)}$ | 280 (@ $T_C = 55^\circ C$) | A | | **Peak Reverse Voltage Range** | $V_{RRM} / V_{DRM}$ | 400 to 1600 | V | | **Peak Non-Repetitive Surge** | $I_{TSM}$ | 7850 | A | | **Gate Trigger Current** | $I_{GT}$ | 150 (max) | mA | | **Operating Temperature** | $T_J$ | -40 to +125 | $^\circ$C | --- ### 2. Physical Construction & Package The **TO-200AB (A-PUK)** package is a specific mechanical design used for high-power efficiency: * **Ceramic Housing:** Provides high insulation and thermal stability. * **Double-Side Cooling:** The device is designed to be clamped between two heat sinks. This allows heat to dissipate from both the top and bottom surfaces, significantly increasing the current-carrying capacity. * **Pressure Contact:** Internal components are held together by external clamping force rather than solder, which improves reliability under thermal cycling. --- ### 3. Electronic Characteristics * **Phase Control:** These are "slow" thyristors compared to inverter types, meaning they are optimized for 50Hz/60Hz AC line commutation. * **Low Conduction Losses:** Designed for high efficiency in high-current states. * **High $dV/dt$ and $dI/dt$:** They possess excellent immunity against rapid voltage changes, preventing accidental triggering. --- ### 4. Common Applications Due to their high current handling and ruggedness, the ST280CH series is used in: 1. **Industrial DC Drives:** Motor speed control for heavy machinery. 2. **AC Soft Starters:** Reducing inrush current in large induction motors. 3. **Controlled Rectifiers:** Converting AC to DC for electrochemical processes (plating, electrolysis). 4. **Welding Equipment:** High-power SCR-based welding power supplies. --- ### 5. Identification Logic (Part Numbering) | Prefix | Current ($I_{T(AV)}$) | Type | Voltage Code | Case | | :--- | :--- | :--- | :--- | :--- | | **ST** | **280** | **CH** (Phase Control) | **10** (1000V) | **C** (Puk) |