IGBTs

IGBTs, or insulated-gate bipolar transistors, are three-terminal power semiconductors that combine the simple voltage-driven gate of a MOSFET with the low conduction losses of a bipolar transistor. This hybrid design makes them the device of choice for medium-to-high power switching applications where high voltage and high current are present alongside the need for efficient, easily controlled switching.

RS Australia stocks a wide range of IGBTs including discrete devices, IGBT chips, and IGBT modules rated from 600V through to 1700V, with components available from leading manufacturers such as Infineon, STMicroelectronics, and ROHM, all reliable producers of high-performance power semiconductors.

Types of IGBT Transistors

IGBTs are supplied in two main product formats, each suited to a different power level and application class.

• Discrete IGBTs (IGBT Chips): Single-die devices supplied in packages such as TO-247, TO-220, D2PAK, and SOT-223, with common voltage classes including the 600V IGBT for motor drives, inverters, and welding equipment, 1200V for industrial drives and renewable inverters, and 1700V for traction and grid-connected applications; modern devices are predominantly Field-Stop (FS) construction, which has largely superseded older Punch-Through (PT) and Non-Punch-Through (NPT) designs across most power IGBTs product lines.
• IGBT Modules (IGBT Power Modules): Co-packaged assemblies that combine multiple IGBT chips with anti-parallel freewheeling diodes inside a single housing, offered in topologies including half-bridge, full-bridge, three-phase inverter (6-in-1), chopper, and boost configurations, with current ratings spanning from around 10A up to 2400A and above to support everything from compact industrial drives through to high-power traction systems.

How Do IGBTs Work?

The IGBT transistor operates as a voltage-controlled switch, blending MOSFET-style gate control with the low-loss conduction characteristics of a bipolar transistor.

• Three Terminals: Every insulated gate bipolar transistor IGBT has a Gate (G), Collector (C), and Emitter (E), corresponding broadly to the base, collector, and emitter of a conventional bipolar transistor.
• Gate Control: Turn-on is achieved by applying around +15V to the gate, whilst turn-off requires the gate to be driven back to 0V or to a negative voltage to ensure clean cut-off.
• Conduction: When the gate is enabled, a MOSFET-style channel forms beneath the gate oxide, which in turn triggers bipolar-style conduction through the device body, producing a low Vce(sat) at high current densities.
• Turn-Off: Removing the gate voltage collapses the MOSFET channel, after which a small tail current associated with minority carrier recombination flows briefly through the device, limiting the maximum practical switching frequency.
• Key Parameters: The most important data sheet figures for any IGBT are Vce, Ic, Vge(th), Vce(sat), and the turn-on and turn-off switching times (ton and toff).

Key Specifications When Selecting an IGBT

The right IGBT for an application depends on a small number of headline parameters that together determine voltage handling, current capability, and thermal performance.

• Collector-Emitter Voltage (Vce): Standard ratings are 600V, 1200V, and 1700V, and the chosen device should provide comfortable margin above the peak voltage seen in the circuit, so a 600V IGBT is typically selected for applications with circuit peaks well below that figure.
• Collector Current (Ic): The continuous current rating must exceed the peak load current the device will see in service, with derating applied for high junction temperatures.
• Saturation Voltage Vce(sat): Lower Vce(sat) reduces conduction losses, although devices optimised for low Vce(sat) often trade off slightly slower switching speeds.
• Switching Speed: Faster devices support higher switching frequencies but typically produce more EMI, so the choice involves balancing efficiency against electromagnetic compatibility.
• Gate Charge (Qg): Higher gate charge requires a more capable gate drive circuit, which directly affects gate driver sizing and overall driver power consumption.
• Package: TO-247 and similar formats are standard for high-current discrete devices, whilst 62mm, EconoPACK, and HiPak housings are typical for an IGBT power module designed for high-power industrial use.
• Temperature Rating: Maximum junction temperature Tj(max) is typically 150°C or 175°C for modern power IGBTs, with thermal design dictated by the headroom available between operating Tj and the rated maximum.

IGBTs vs MOSFETs

IGBTs and MOSFETs both serve as voltage-controlled power switches, but each is best suited to a different combination of voltage, current, and switching frequency.

When to Choose an IGBT

• Better suited to high-voltage (typically above 300V) and high-current applications where MOSFETs would suffer excessive conduction losses.
• Lower Vce(sat) produces less conduction loss at high current densities than the equivalent MOSFET's RDS(on).
• Preferred for motor drives, inverters, welding equipment, and traction systems where robustness and current handling matter more than ultra-high switching speed.
• Typical switching frequencies range from around 1 kHz to 50 kHz, with some optimised devices reaching higher.

When to Choose a MOSFET

• Lower losses than IGBTs at lower voltages (below around 300V) and lower currents, where their RDS(on) is favourable.
• Faster switching without the minority carrier storage that produces the IGBT tail current, making them better suited to designs operating above 100 kHz.
• Preferred for DC-DC converters, battery management systems, and low-voltage motor control applications.

In the crossover zone of around 300 to 600V, the choice between an IGBT and a MOSFET depends on the combination of switching frequency, current level, and thermal design constraints, with both technologies viable depending on the specifics of the design.

Industrial Applications of IGBTs

IGBTs are deployed across virtually every sector of Australia's industrial and energy infrastructure where efficient high-power switching is required.

• Industrial Motor Drives and VSDs: 600V and 1200V devices are used extensively in the three-phase inverter bridges that drive variable speed drives for industrial motors across Australia's manufacturing and processing facilities.
• Renewable Energy Inverters: IGBT-based switching stages form the core of grid-tie inverters for both solar PV and wind installations, converting DC generation into grid-compliant AC power.
• Uninterruptible Power Supplies (UPS): IGBTs handle the inverter stage in commercial and industrial UPS systems, providing clean AC output during mains failure events to protect critical loads.
• Welding Equipment: High-frequency IGBT switching underpins modern inverter-based welding machines, providing precise arc control alongside significant size and weight reductions over older transformer-based welders.
• Traction and Electric Vehicles: 1200V and 1700V IGBT power module assemblies are used in traction inverters for rail systems and increasingly in electric vehicle drive systems where high power density is essential.
• Air Conditioning and HVAC: IGBT-based inverter drives for variable-speed compressors deliver improved energy efficiency and finer temperature control in commercial and residential HVAC equipment across Australia.

Buy IGBTs Online from RS Australia

RS Australia is a trusted supplier of power semiconductors, with an extensive range of IGBTs from leading manufacturers including Infineon, STMicroelectronics and ROHM, covering discrete devices, IGBT chips, and IGBT modules across the standard 600V, 1200V, and 1700V voltage classes. The full product selection can be filtered by maximum collector-emitter voltage, continuous collector current, package type, configuration, and switching characteristics, helping engineers identify the right IGBT transistor for motor drives, renewable inverters, traction systems, or welding equipment.

RS Australia also acts as a one-stop procurement store for a wide range of semiconductor components including memory chips, logic ICs and digital transistors. Browse the full range and order your insulated-gate bipolar transistor devices online at RS Australia today. For more information on our delivery options and fees, please visit our delivery information page.