What is the CTI (Comparative Tracking Index)?

CTI is the abbreviation for “Comparative Tracking Index”. Those with the comparative tracking index, that indicates tracking resistance as a molding resin, in the material group I in the table are required. The resin molding of power modules used in harsh environment, such as for solar panel generation and wind power generation, improvement in tracking […]

IC, IC, pulse are included in the absolute maximum ratings. What do they mean?

“Including the V Series, –IC represents the maximum DC forward current which is allowed for the built-in diode, and –Ic, pulse represents the maximum pulse forward current which is allowed for the built-in diode. From X Series on, to be easily recognized as compliant to IEC standards and as diode elements, they have been changed […]

What is the insulation voltage test method for IGBT module?

Short-circuit all main and control terminals and apply a specified AC voltage between all terminals and the backside metal area for a specified time period.

What is the active clamp circuit?

It is a protection circuit, added to suppress a surge voltage between the collector and the emitter.

Is there any way to simplify the design of the gate drive circuit for the IGBT module and furthermore, include the protection circuit?

IGBT gate drive ICs are supplied from many companies including BROADCOM, Renesas Electronics, Texas Instruments, ISAHAYA ELECTRONICS and TOSHIBA. As the ICs contain short-circuit protection and voltage drop protection circuits within the chip, design of the drive circuit will be simplified. An IGBT module evaluation board with mounted drive IC is available. Please download the […]

Overheat protection and temperature output functions are built in a small IPM. Which temperature is detected?

The temperature of LVIC (low voltage IC for low arm IGBT drive) is detected. It is not the junction temperature of the IGBT.

What is the variance of the internal gate resistance (rg) in an IGBT module?

It is ±10%. However, it is not guaranteed.

What is the successor of the thermal grease G746 (by Shin-Etsu Chemical Co., Ltd) which is recommended in the IGBT Module Application Note?

Fuji recommends the paste ‘G776’. Please contact Shin-Etsu Chemical for details. However, Fuji Electric does not guarantee its characteristics when combined with IGBT module.

The alarm output terminal VFO of the small IPM goes to low level when an anomaly occurs within the IPM. What is the alarm output pulse width tFO?

The alarm output period tFO is minimum 20μs, but typical value is about 50μs. The typical value, however, is not guaranteed.

What do I have to take care of when using an IGBT module in a converter circuit?

If diode loss increases, check that the diode temperature does not exceed the absolute maximum ratings, and that ΔTvj power cycle capacity is satisfied. Also check that the system will not be broken due to inrush current at power-on or temporary interruption of power.