You almost have to show some sympathy for the insulated gate bipolar transistor (IGBT). They have been the workhorse of many motor and power projects for decades and will continue to play that role. But now it seems that MOSFETs, be they base silicon, silicon carbide (SiC) or gallium nitride (GaN), are getting all the attention and fame.
While IGBTs still play an important role in power switch designs, the obvious question is, “When do you use what type of device?” The answer is usually, “It depends on the situation.” The answer depends on the specific parameters of the available equipment and the priority of the project.
There are no hard and fast ‘pick one/pick the other’ rules, but a general comparative overview provides insight and a starting point (Figure 1).
Please note that the dividing lines are not “hard” boundaries, but rather blurred ones, and they are constantly changing as device processes and technologies evolve. (The links below give some perspective on the situation between IGBTs and MOSFETs; note that some of these views are somewhat self-serving and biased, but still worth reading).
Although IGBTs are less well known, suppliers are still releasing new products. Toshiba Electronics has launched two IGBTs with drivers for three-phase brushless direct current (BLDC) motors for applications such as fan motors, blowers, air conditioners, air purifiers and pumps.
Each of these “intelligent power devices” (IPDs) contains three 600V rated IGBTs and associated high- and low-side gate drivers as a single-chip solution in one compact package. The TPD4163F has a rated DC output current (IOUT) of 1A and the TPD4164F has a rated DC output current (IOUT) of 2A.
These devices can be controlled directly from the logic outputs of a microcontroller or motor controller and use a minimum number of discrete passive components (Figure 2).
The saturation voltages (VCEsat) of the IGBT TPD4163F and TPD4164F are 2.6 V and 3.0 V, respectively, and the diode forward voltage (VF) is 2.0 V and 2.5 V, respectively.
Both devices are available in a miniature surface mount HSSOP31 package measuring just 17.5 x 11.93 x 2.2 mm. This reduces the PCB area by approximately 63% compared to Toshiba’s existing DIP26 packaged products, thereby significantly reducing the space required for the motor drive PCB.
These devices are designed to recognize that power supply instability may occur in certain geographic regions, which may result in large fluctuations in supply voltage. To improve reliability, the nominal supply voltage (VBB) has been increased from 500V to 600V to provide additional design margin.
In addition to the data sheets for the TPD4163F and TPD4164F, Toshiba has provided documentation for a 120 to 340 V vector-controlled BLDC motor demonstration circuit using the TPD4164F in combination with the company’s TMPM374FWUG microcontroller. The 130x85x53.4mm PCB design (Figure 3) is fully supported by design guides, sample software, specifications, schematics, PCB layer details and more.
Toshiba is not the only supplier releasing new IGBTs. STMicroelectronics has released a new IGBT with an increased breakdown voltage of up to 1350 V and a maximum operating temperature of 175°C. The STPOWER IH2 series IGBTs improve the power conversion efficiency of single-switch quasi-resonant converters over a wide switching frequency range from 16 to 60 kHz.
These IGBTs are ideal for induction heating applications including home appliances such as cookers, inverter microwave ovens and rice cookers. ST claims that in 2kW applications, power consumption is reduced by up to 11%.
The STGWA25IH135DF2 is a 25 A IGBT in a TO-247 long lead package, while the other similar STGWA35IH135DF2 is rated at 35 A (Figure 4). The IGBT has a low saturation voltage Vce(sat) of 1.7 V (typical), which provides low power-up dissipation.
In addition, Vce(sat) has a positive temperature coefficient and precise distribution of parameters between devices, which helps simplify the design and easily parallelize multiple IGBTs for higher power applications. Low flyback diode voltage drop and optimized turn-off energy improve the efficiency of single-switch quasi-resonant converters operating from 16 to 60 kHz.
Prices start at $1.39 for the STGWA25IH135DF2 and $1.69 for the STGWA35IH135DF2 (1,000 unit order).
Wolfspeed, “Choosing the Best Option for Your Design: Advantages of Silicon Carbide MOSFETs over IGBTs”
Post time: Mar-28-2024