Fast Switching Thyristors 100A – 320A, Stud Package

Fast Switching Thyristors (TFI) AS ENERGITM in stud design, also called "Fast Impulse Thyristors" (TFI) is a fast switching semiconductor device. Fast switching thyristors meet requirements, such as increased di/dt resistance, low switching losses, short turn-on and turn-off time. Regulating and converting DC and AC currents to 320A at frequency range is up to 10kHz in circuits with voltages to 1800V (depending on series).

Power stud fast switching thyristors series TFI have the following types (current): 100 A, 120 A, 125 A, 150 A, 160 A, 200 A, 250 A, 300 A, 320 Ampere.

Series of high-power stud fast switching thyristors

Part numbering guide for power stud fast switching thyristors

Technical passport for power stud fast switching thyristors

Installation recommendations for power stud thyristors

Fast switching thyristors are thyristors with additionally normalized reverse recovery charge Qrr. These devices are adapted for switching current pulses with a high rate of rise at the front and high amplitude.

Fast thyristors are devices with reduced tq, trr, Qrr values and with a higher value (diT/dt)cr (up to 2500 A/µs) designed to operate at higher frequencies modes (up to 10kHz). The thyristor parameters of VTM, tq, Qrr are interconnected, so a decrease in the value of tq and Qrr leads to an increase in VTM.

Fast switching (pulse) thyristors are characterized with a very low turn-off time that sets them apart from the standard models. They are used in welding, induction heating and melting, electric transportation, AC drives, UPS, and other systems requiring short turn-on and turn-off times. The thyristors have an industry-standard ceramic sealed housing isolating the functional part and the semiconductor element from mechanical impacts and environment.

The polarity of the thyristor is determined by the icon on the case. On this page are schematic diagrams and circuits of stud fast thyristors with Anode, Cathode, and control electrode (Gate). The technical specifications, part numbering guide, polarity, dimensions and recommended coolers for stud fast thyristors are listed below.

Air and water heat sinks are used to cool the stud thyristors. To provide reliable thermal and electrical contact with the heatsink a tightening torque Md must be observed during assembly. For better heat dissipation of thyristor during assembly, heat conducting paste is used.

The fast thyristors have a sealed ceramic housing isolating the functional part and the semiconductor element from mechanical impacts and environment.

Fast switching stud thyristors from AS Energi Global LLC have the following features: low static and dynamic losses, high values of VDRM/VRRM, extensive experience of using the devices in various industries, range of voltages from 600 to 1800 V and amperages from 100 to 320 A, high resistance to thermal and electric cycling, natural or forced air cooling.

Our company provides a quality guarantee for stud thyristors of 2 years from the date of purchase. When supplying thyristors, if necessary, we provide quality declaration and certificate of conformity.

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The final price of fast switching thyristors depends on the voltage class, quantity, delivery terms, manufacturer, country of origin and form of payment.

For questions regarding the acquisition of High Power Thyristors, Diodes send an email request to:

[email protected]

And we will provide you a commercial offer for delivery.
For a large number, we will provide an individual price!!!

We are open to manufacture products at our production facilities
according to your requests and technical task.

Photo Gallery

The photo gallery shows many different semiconductor devices, semiconductor chips and SCRs produced by AS ENERGITM, examples of test reports.

Stud Fast Switching Thyristors TFI261, TFI361, TFI271, TFI371 (100A – 320A)

Type IT(AV)
ITSM I2t dv/dt di/dt tq Tvj max Rth(j-c) Md
W Package Thread Data-sheet
A V kA kA2·s V/µs A/µs µs ºC ºC/W N·m g mm PDF
100 A
TFI361-100 100 (93) 600-1200 2.5 312 1000 800 12.5-50 125 0.150 25 240 ST6 M20x1.5 PDF
125 A
TFI261-125 125 (88) 800-1400 4.5 80 200-2500 1000 16-32 125 0.150 25 240 ST6
M20x1.5 PDF
TFI361-125 129 (80) 600-1200 2.6 100 1000 800 20-25 125 0.160 25 240 ST6 M20x1.5 PDF
160 A
TFI261-160 160 (83) 800-1400 5.5 140 200-2500 1000 20-40 125 0.150 25 240 ST6
M20x1.5 PDF
TFI271-160 160 (98) 1000-1400 6.0 170 200-2500 1600 16-32 125 0.085 30 440 ST7 M24x1.5 PDF
TFI371-160 160 (98) 600-1200 4.0 80 1000 1000 10-32 125 0.084 30 440 ST7 M24x1.5 PDF
200 A
TFI271-200 200 (95) 1000-1400 6.5 200 200-2500 1600 20-40 125 0.085 30 440 ST7 M24x1.5 PDF
TFI371-200 200 (90) 600-1800 6.0 180 1000 1000 25-50 125 0.084 30 440 ST7
M24x1.5 PDF
250 A
TFI271-250 250 (88) 1000-1400 7.0 230 200-2500 1600 25-50 125 0.085 30 440 ST7 M24x1.5 PDF
TFI371-250 250 (93) 1000-1400 7.0 240 200-2500 1600 25-50 125 0.085 30 470 ST7 M24x1.5 PDF
320 A
TFI271-320 320 (77) 1000-1400 7.5 260 200-2500 1600 32-63 125 0.080 30 440 ST7 M24x1.5 PDF

Part Numbering Guide for Fast Switching Thyristors:

TFI 271 200 14 9 6 3
TFI brand AS ENERGITM Fast Switching Thyristor (Fast Impulse Thyristor)
271 Thyristor type (stud type).
200 Average current in open state IT(AV), Amp.
14 Voltage class VRRM / 100  (Nominal voltage – 1400 V).
9 Parameter of the critical rate of rise of off-state voltage (dVD/dt)crit:
Alpha-numeric coding 0 P3 E3 A3 P2 K2 Е2 A2 T1 P1 M1
Digital coding 0 1 2 3 4 5 6 7 8 9
Value, V/µs not standardized 20 50 100 200 320 500 1000 1600 2000 2500
6 Parameter of turn-off time tq:
Alpha-numeric coding 0 C3 E3 H3 K3 M3 P3 T3 X3 A4 B4 C4 E4
Digital coding 0 1 2 3 4 5 6 7 8 9
Value, µs not standardized 63 50 40 32 25 20 16 12.5 10 8 6.3 5
3 Parameter of turn-on time tgt:
Alpha-numeric coding 0 T3 A4 B4 C4 H4 K4 M4 P4 T4 X4 A5 C5
Digital coding 0 1 2 3 4 5 6 7 8
Value, µs not standardized 16 10 8 6.3 4 3.2 2.5 2.0 1.6 1.25 1.0 0.63

Technical Passport for Thyristors (sample):

When supplying thyristors, if necessary, we provide technical passport and certificate of conformity.

  • Technical Passport
  • Technical Passport
  • Technical Passport

High Power Semiconductors AS ENERGITM

Our company is engaged in the manufacturer and sale of wide range of power semiconductors (power thyristors, modules, rectifier diodes, rotor and welding diodes, triacs etc.) currents up to 15000A and voltages to 9000V, and air and water heatsinks to them. You can buy semiconductors in any volumes, and when ordering large lots, the price will be lower.
We have earned the trust of customers and supply products all over the world.

To purchase High Power Thyristors, Diodes, Modules send an email request to:

[email protected]

And we will provide you a commercial offer for delivery.

Photo of Fast Switching (Stud) Thyristors:

  • Fast Switching Stud Thyristor
  • Fast Switching Stud Thyristor
  • Fast Switching Stud Thyristor
  • Fast Switching Stud Thyristor
  • Fast Switching Stud Thyristor
  • Fast Switching Stud Thyristor

Installation recommendations for fast thyristors:

Assembling stud fast thyristor with a heatsink

The reliability of heat transfer and electrical contact between the mating surfaces of the thyristor and the cooler over the entire temperature range is ensured by appropriate torque (clamping force).

Before assembly you should perform visual inspection (1) contact surfaces for mechanical damages and wipe (2), soaked with alcohol (toluene, gasoline, acetone).

After inspection, fix the current contacts (leads), install a pin to fix the alignment of the structure.

To improve the parameters of heat transfer it is recommended to lubricate (3) a thin layer of silicone thermal conductive paste before the assembly, which is not a mandatory condition for installation.

Install the thyristor (3), the second part of the cooler, the fiberglass insulator and the thrust washer.

To thread the traverse (4) and evenly tighten the nuts. Make sure no misalignment and evenness of the contact surfaces.

When the parts are sufficiently clamped but moveable, we recommend placing the cooler on a flat surface and checking the tolerance for parallelism of the overall adjacent plane of the surfaces (5).

Clamp each nut in turn (about a quarter turn) to the stop (6). The amount of deflection of the traverse determines whether the achieved clamping force corresponds to the required one.

After installation, the fasteners (nuts and washers) must be additionally secured against corrosion.

Tips and recommendations for power thyristors:

The power thyristors should not be operated for long periods of time at their limit load for all parameters. In this case, the safety factor is determined by the required degree of reliability of the device.

Replace a failed power thyristor with a thyristor that matches the parameters of the one being replaced.

Supercooling must be provided when operating in an environment with an elevated ambient temperature.

Periodic cleaning of power thyristors and coolers to remove dust and contaminants is recommended to ensure proper heat dissipation.

Inductive current dividers (often twisted toroidal wire) should be used to equalize currents between power thyristors connected in parallel. The most popular connection methods are closed circuit, common coil circuit, or power thyristor. The efficiency of current dividers in this case is determined by the cross section of the magnetic wire.

Prevention of voltage unbalance when power thyristors are connected in series is achieved by using shunt resistors connected in parallel with each thyristor. Voltage equalization in transient conditions is provided by connecting capacitors in parallel to each thyristor.

Device under voltage

It is strictly forbidden to touch power thyristors under high voltage during operation.

icon Why choose AS ENERGITM

  • Own production facilities, including semiconductor silicon chips production
  • European brand - 100% quality, favorable price, short production terms
  • Over 20 years of experience in the semiconductor industry
  • Clients from more than 50 countries trust us
  • 20000 items in the product line for currents from 10A to 15000A, voltages from 100V to 9000V
  • We produce analogues of other manufacturers' products
  • Guaranteed certified quality, warranty period of operation - 2 years


Quality Warranty

Our products are certified and correspond to international standards.
Our company provides a quality guarantee for products of 2 years.
We provide certificates of conformity, reliability reports, data sheets and technical passports at the request of the customer.


Each product is tested for the main parameters, and Test reports of the parameters for each product are provided.

Test Report

Geography of partnership

AS ENERGITM company manufactures and supplies power semiconductors to more than 50 countries around the world.


Logistics and Delivery

We deliver our products all over the world with the services of logistics companies: DHL, TNT, UPS, EMS, Fedex, Aramex.
Products can be delivered by any means of transport: air, sea, rail and road.


AS ENERGITM Semiconductors Manufacturing

Our products range includes rectifier diodes, phase control thyristors in disc and stud design, avalanche diodes and thyristors, fast switching, high frequency thyristors, fast recovery, welding and rotor diodes, triacs, bridge rectifiers, power modules (thyristor, diode, thyristor-diode, IGBT), and air and water heatsinks to them.

Power diodes and thyristors are produced for currents from 10A to 15000A, voltage range from 100V to 9000V.
Power diode and thyristor modules are produced from 25A and up to 1250A, voltage range 400V - 4400V.
The range of power semiconductors also includes equivalent, replacement, analogue and alternative semiconductor devices of global manufacturers.

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