Content last revised on November 13, 2025
## TT 250 N 18 KOF 25CN | High-Reliability 1800V Dual Thyristor Module for Phase Control
The TT 250 N 18 KOF 25CN is an industry-standard dual thyristor module engineered for robust and precise control in high-power applications. With an 1800V blocking voltage and a 250A average current rating, this component provides a dependable solution for phase control rectification, AC power regulation, and soft-starting circuits. Its design prioritizes thermal efficiency and long-term reliability, making it a cornerstone for demanding industrial systems.
Key Performance Characteristics
Engineered for seamless integration and durability, the TT 250 N 18 KOF 25CN offers a compelling set of features for power system designers:
- High Blocking Voltage: A repetitive peak off-state voltage (VDRM/VRRM) of 1800V ensures a substantial safety margin for operation on 400V, 480V, and even 690V AC lines.
- Robust Current Handling: Delivers an average on-state current (IT(AV)) of 250A, suitable for controlling high-power industrial loads.
- Industry-Standard Housing: The KOF package is designed for straightforward mechanical mounting, simplifying assembly and thermal management.
- Superior Thermal Management: Features an electrically isolated baseplate, which reduces system complexity by allowing direct mounting to a common heatsink without additional insulation materials, thereby improving thermal transfer.
Key Parameters Overview
The following table outlines the critical electrical and thermal specifications that define the operational envelope of the TT 250 N 18 KOF 25CN. For comprehensive data and characteristic curves, designers should consult the official product datasheet. For a deeper understanding of how parameters influence real-world performance, explore our guide on decoding power module datasheets.
| Parameter | Symbol | Value |
|---|---|---|
| Repetitive Peak Off-State Voltage | VDRM / VRRM | 1800 V |
| Average On-State Current (TC = 85°C) | IT(AV) | 250 A |
| RMS On-State Current | IT(RMS) | 393 A |
| Surge Current (tp = 10ms, Tvj = 25°C) | ITSM | 6500 A |
| Peak Gate Current | IGM | 10 A |
| Operating Junction Temperature Range | Tvj op | -40 to +125 °C |
Application Scenarios & Engineering Value
The unique characteristics of the TT 250 N 18 KOF 25CN make it an ideal choice for specific power conversion tasks where ruggedness and cost-effectiveness are paramount.
- Controlled Rectifiers: In applications like large-scale DC power supplies or industrial battery chargers, this module enables the creation of efficient and highly controllable front-end rectifiers. Its high voltage rating provides resilience against line voltage transients common in industrial environments.
- AC Soft Starters: For large induction motors, the module facilitates gradual voltage ramping through phase angle control. This significantly reduces inrush currents, minimizing mechanical stress on the motor and electrical stress on the grid.
- Industrial Heating Control: In resistive heating applications such as industrial furnaces or plastic molding machines, the TT 250 N 18 KOF 25CN allows for precise power regulation, ensuring stable process temperatures and optimizing energy consumption. The robust thermal design is critical for handling the continuous power dissipation in these systems.
Technical Deep Dive: The Foundation of Reliability
Two core technological features underpin the exceptional reliability of the TT 250 N 18 KOF 25CN: pressure contact technology and the advanced baseplate design.
Pressure Contact Technology: Unlike soldered modules, this design uses internal spring-loaded contacts to press the silicon die against the substrate. This eliminates solder fatigue, a common failure mode in power modules subjected to frequent temperature changes. The result is a significantly higher power cycling capability, making the module exceptionally durable in applications with intermittent or cyclical loads, such as motor soft starters.
Electrically Isolated Baseplate: The module is built on a Direct Bonded Copper (DBC) substrate, typically using a ceramic like Aluminum Oxide (Al2O3). This structure offers excellent electrical isolation (typically >2500V) while maintaining a low thermal resistance. For the system designer, this means simplified assembly, reduced bill-of-materials (no need for separate insulating pads), and a more reliable thermal path from the silicon junction to the heatsink.
Frequently Asked Questions (FAQ) for Design Engineers
1. What are the primary considerations for the gate drive circuit?
A strong gate pulse is crucial for ensuring a fast and complete turn-on of the thyristor, which minimizes switching losses. A pulse with a sharp rising edge and sufficient current amplitude (as specified in the datasheet's IGT and VGT parameters) is required. For reliable operation, especially with inductive loads, a continuous gate current or a train of pulses is often recommended after the initial firing pulse.
2. Is this module suitable for high-frequency applications?
The TT 250 N 18 KOF 25CN is a phase-control thyristor, optimized for line-frequency (50/60 Hz) applications. Its turn-off time (tq) is not designed for high-frequency switching. For applications requiring frequencies above a few hundred Hertz, such as modern Variable Frequency Drives (VFDs) or high-frequency power supplies, alternative components like IGBT modules would be the appropriate choice.
