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Examples of Actual IGBT IPMs: Absolute Maximum Ratings
2023.09.13
Points of this article
・An absolute maximum rating must never be exceeded, regardless of the category.
・Absolute maximum ratings for IGBT IPMs should likewise be understood as essentially the same as those for semiconductor devices.
・Absolute maximum ratings do not ensure operation or guarantee a device characteristic; therefore designs must be based on specifications for recommended operating conditions and electrical characteristics.
In the previous article, actual IGBT IPM examples were considered and their specifications and functions were summarized. Here, the absolute maximum ratings of IGBT IPMs are explained. As in the previous article, as examples of IGBT IPMs, ROHM’s 3rd-generation IGBT IPMs of the BM6437x series are used in the explanations.
Examples of Actual IGBT IPMs: Absolute Maximum Ratings
By way of review, we first reaffirm the meaning of an absolute maximum rating. If one’s knowledge of the meaning of an absolute maximum rating is inadequate, a serious accident could occur, and so an accurate understanding of the concept and rigorous application are required of designers as well as of users. Here, absolute maximum ratings for IGBT IPMs are explained, but in essence the definitions given here can similarly be applied to other semiconductor devices as well.
Where absolute maximum ratings of semiconductor devices are concerned, in essence the definitions of terms in the “JIS C 7032 General Rules for Transistors” are used. The definition of absolute maximum ratings is “limit values that must not be exceeded even momentarily, and any two of which must not be reached simultaneously.” This is interpreted to mean “the value of any item in the absolute maximum ratings must never be exceeded.” In other words, absolute maximum ratings have no tolerance range.
Below are presented the absolute maximum ratings of a BM64374S-VA IGBT IPM, together with related explanations. The meanings and intentions of the different ratings should be understandable. Pin names and the like appear in the table; please refer to the linked data sheet.
Of course in the design stage, measures must be taken to ensure that absolute maximum ratings are not exceeded. If they are exceeded, and the design specifications cannot be modified, an IGBT IPM that satisfies the design specifications should be considered.
Absolute Maximum Ratings: Inverter Section
| Item | Symbol | Ratings | Meaning & Description | |
|---|---|---|---|---|
| Supply Voltage | VP | 450 V | The maximum DC voltage that can be applied across the P-NU, NV, NW pins when not in the switching state. In cases where this voltage may be exceeded, a limiting circuit is required. | |
| Supply Voltage (Surge) | VP(surge) | 500 V | The maximum surge voltage between P-NU, NV, NW in the switching state. In cases where this voltage may be exceeded, reduction of the bus inductance or addition of a snubber circuit is necessary. | |
| Collector-Emitter Voltage | VCES | 600 V | Maximum voltage that can be applied across C and E of an internal IGBT. | |
| Collector Current | DC | IC | ±15 A | Maximum continuous DC collector current at TC =25℃. |
| PEAK | ICP | ±30 A | Maximum pulse collector current (1 ms or less) at TC =25℃. | |
| Junction Temperature | Tjmax | 150℃ | The maximum instantaneous junction temperature of an internal power chip is 150℃ (@TC =100℃ or lower), but in order to ensure safe operation, it is recommended that the average junction temperature be 125℃ or lower (@TC =100℃ or lower). A power chip is not immediately damaged at Tj =150℃, but the power cycle lifetime is shortened. | |
Absolute Maximum Ratings: Control Section
| Item | Symbol | Ratings | Meaning & Description |
|---|---|---|---|
| Control Power Supply Voltage | VCC | 20 V | The maximum DC voltage that can be applied across the HVIC HVCC-GND pins and across the LVIC LVCC-GND pins. |
| Floating Control Power Supply Voltage | VBS | 20 V | Maximum DC voltage that can be applied across the VBU-U, VBV-V, and VBW-W pins as high side IGBT driving power supply voltages. |
| Control Input Voltage | VIN | -0.5 V to VCC +0.5 V | Voltages that can be applied across the HINX-GND and the LINX-GND pins (X=U, V, W). |
| Fault Output Supply Voltage | VFO | -0.5 V to VCC +0.5 V | Voltage that can be applied across the FO-GND pins. |
| Fault Output Current | IFO | 1 mA | Sink current flowing between the FO-GND pins. |
| Current Sensing Input Voltage | VCIN | -0.5 V to +7.0 V | Voltage that can be applied across the CIN-GND pins. |
| Temperature Output Voltage | VOT | -0.5 V to +7.0 V | Voltage that can be applied across the VOT-GND pins. |
Absolute Maximum Ratings: Bootstrap Diode Section
| Item | Symbol | Ratings | Meaning & Description |
|---|---|---|---|
| Reverse Voltage | VRB | 600 V | Maximum voltage that can be applied to an internal bootstrap diode. |
| Junction Temperature | TjmaxD | 150℃ | The maximum instantaneous junction temperature for an internal power chip is 150℃ (@TC =100℃ or lower), but for safe operation, it is recommended that the average junction temperature be 125℃ or lower (@TC=100℃ or lower). |
Absolute Maximum Ratings: Overall System
| Item | Symbol | Ratings | Meaning & Description |
|---|---|---|---|
| Self Protection Supply Voltage (SCP capability) | VP(PROT) | 400 V | The maximum power supply voltage that an IGBT can safely shut off using a protection function when, with VCC =13.5 V to 16.5 V, the IGBT enters a short-circuited or overcurrent state within 2 µs under non-repeating conditions. |
| Module Case Temperature | TC | -25℃ to＋115℃ | The value measured with a thermocouple when a groove or the like is formed in the heat sink upon measurement of TC directly below the power chip. ※ See the “TC measurement point” diagram below. |
| Isolation Voltage | Viso | 1500 Vrms | Isolation voltage between a ceramic heat-dissipating surface and all pins (shorted). When using a planar heat sink, there is the possibility of electrical discharge between the heat sink and pins, and so the value is 1500 Vrms. As indicated in the diagram on the lower right, when a convex heat sink is used, with the distance between the heat sink and the pins expanded (a distance of 2.5 mm or greater is recommended), a 2500 Vrms requirement is satisfied. UL certification is obtained when using a convex heat sink at an isolation voltage of 2500 Vrms. |
＜TC Measurement Point＞
The above is an explanation of absolute maximum ratings; but the values of absolute maximum ratings are in the end ratings, and while an IGBT IPM can tolerate values up to the absolute maximum rating, this does not mean that normal operation is guaranteed. The “specifications” in the “recommended operating conditions” and the “electrical characteristics” appearing on the data sheet are the values that ensure normal operation and characteristics. The absolute maximum ratings and these values must be compared, and the conditions of use studied.
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