Gate Turn-Off Thyristors

Gate Turn-Off Thyristors

Gate Turn-Off Thyristors

Gate Turn-Off Thyristors

Dynex range of Gate Turn-Off Thyristor devices range from 1300V to 4500V with current ratings from 225A to 1180A.

Gate Turn-Off Thyristors

Gate Turn Off Thyristors


Dynex manufacture Gate Turn-off Thyristors (GTOs) to service the maintenance market that exists due to long service life of traction equipment. Dynex Gate Turn-off Thyristor devices range from 1300V to 4500V with current ratings of 225A to 1180A.

Gate Turn Off Thyristors

Gate Turn Off Thyristors Details

The Gate Turn-off Thyristors (GTO's) have an inherent fast turn-on however, are ideally designed to turn off high current making it useful in PWM (Pulse Width Modulation) and chopper circuits.

The range of Gate Turn-off Thyristors are primarily designed for use in railway traction, light rail propulsion drives and auxiliary converters. Suitable applications for Gate Turn-off Thyristors include those requiring on/ off switching of DC in a controlled manner such as, AC motor inverters, choppers and DC-DC converters.

Gate Turn Off Thyristors

Gate Turn Off Thyristors Features

  • Double side cooling
  • High reliability in service
  • High voltage capability
  • Fault protection without fuses
  • High surge current capability
  • Turn-off capability

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Gate Turn Off Thyristor Frequently Asked Questions

What size of snubber circuit design should I use and what are the tradeoffs I need to consider?

Please refer to our Application Notes AN6175 for technical guidance

When might I consider to apply a bipolar based solution?

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.

Why is there such a broad range of Qrr (stored charge) and VF (forward voltage drop)?

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.

What makes a Dynex Gate Turn-off Thyristor so reliable?

Dynex Gate Turn-off Thyristors (GTOs) have a track record for reliability and performance in demanding operational environments such as railway traction. This is achieved by including a rigorous frequency test step that screens out potential early life failures.

How does a gate turn-off thyristor (GTO) work?

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.

What are the applications for a gate turnoff thyristor?

GTO thyristors are used in high performance drive systems, traction applications and DC drives.

Dynex range of Gate Turnoff Thyristors are designed to service the maintenance market that exists due to long service life of traction equipment. Our Gate Turnoff Thyristors have a track record for reliability and performance achieved by including a frequency test step and screens out potential initial mortality.

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