High-Power Thyristors - Designed and Manufactured in the UK

Please refer to our Application Notes AN6175 for technical guidance

You should consider the electrical operational conditions for your product such as switching frequency, rail voltages, power dissipation and the likely occurrence of over specification excursions (see AN5948) as bipolar products are robust and more likely to withstand these without failure. The cost and difficulty of service team visits or contractual penalties for non-operation should be considered if applicable. Bipolar devices housed in ‘hockey puck style packages’ are all hermetic devices.

Dynex ‘s Bipolar datasheets show the full range of Qrr & Vf possible, but you would normally want to enhance. Typically, when evaluating Qrr and VF, the maximum Qrr and minimum VF or the minimum Qrr and maximum VF should be considered in tandem. Once you have defined your system specification you should consult with your local Dynex contact to agree the required Qrr & Vf values for your design.

Dynex Gate Turn-off Thyristors have a track record for reliability and performance in demanding operational environments such as railway traction. This is achieved by including a frequency test step that screens out potential infant mortality.

A gate turn-off thyristor (GTO) is a high-power semiconductor device. It works by acting as a switch in high voltage circuits. Like a thyristor (SCR Silicon-Controlled Rectifier) it has 3 terminals; anode, cathode and a gate terminal. Both a GTO and SCR have a controlled turn on function via the application of a  positive pulse to the gate terminal, but the GTO also has controlled turn-off function by the application of a negative pulse to the gate terminal. An SCR only turns off when the forward current drops below the threshold holding current  The turn-off time is typically more than 10 times faster than for an SCR (silicon-controlled rectifier) thyristor.

High-power bipolar thyristors offer low conduction losses, high current-carrying capability and strong surge current performance, making them suitable for demanding power conversion and control applications.

Press-pack devices also provide efficient double-sided cooling and robust mechanical construction, supporting reliable operation in high-power industrial systems.

Dynex offers a comprehensive range of thyristor technologies to meet different voltage, current and application requirements.

Dynex's i2 Phase Control Thyristors with options ranging between 4200V - 8500V offers:

• thinner silicon with low conduction losses 
• utilises 100% of the blocking capability of the silicon
• the unique bevel maximises the current and surge ratings by increasing the contact area
• exclusive aluminium diffusion techniques allow us to fine tune the diffusion profile making the i2 Thyristors more robust and reliable
   

A Thyristor is a broad category of semiconductor devices with similar characteristics including SCR's and GTO's. Whereas a SCR is a specific type of Thyristor. 

Each type of thyristor has its own unique characteristics and applications, however they all share the fundamental ability to control the flow of electrical current through them.

A SCR is primarily used as a one directional switch conducting current from an anode to cathode. Used in applications where there is a need to control DC power such as in high-voltage applications. Phase Controlled Thyristors are also known as phase-controlled rectifiers or SCR's and are used to provide phase-controlled rectification. They are used in motor drives and power supply applications.

Gate Turn-off Thyristors are used in various applications where precise control of high electrical power levels is required such as in HVDC transmission systems to convert AC to DC current for efficient long distance power transmission and back again for distribution.

The main difference, therefore lies in their control characteristics.

DYNEX are able to design customer specific Thyristors based on existing technology platform to achieve specific requirements:

• Lead type 
• Lead length  
• Bespoke Printing 
• Custom Test specs 
• Parameter matching: Series (Qrr matching), Parallel (Vtm matching)

We are actively expanding our Bipolar wafer fab capacity to address increasing customer demand.