Fuji Electric Co., Ltd.

Tamao Kajiwara

Manabu Watanabe

A semiconductor apparatus, including an intelligent power module, facilitates preventing sudden stop of an inverter due to an anomaly from affecting a factory operation adversely. When an anomaly occurs in IGBTs of the inverter, one of protection circuits outputs an alarm signal via an alarm enable line. In advance to the alarm signal, when the protection circuit detects a sign of a possible anomaly from a collector current or a chip temperature of any of the IGBTs exceeding a second predetermined collector current level or a second predetermined temperature level higher than the normal collector current value or the normal chip temperature but lower than a first predetermined collector current level or a first predetermined temperature level for outputting the alarm signal, the protection circuit outputs a preliminary alarm signal via a preliminary alarm line without turning off the pertinent IGBT.

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Nagano, Japan

Tamao Kajiwara