Integrated power module diagnostic unit

Abstract

An integrated power module combining drivers and power devices includes a diagnosis module integrated with or connected to the integrated power module. That includes protectors. The protectors provides protection against power device failure, transistor stack failure, gate drive failure, power failure, and other conditions. In a first level of diagnosis and protection, a gate driver is responsive to hard faults, such as short circuit and under voltage conditions, to disenable the power devices, for example, switching transistors of an inverter. In addition, the first level of protection includes soft faults, such as detection of overcurrent and over temperature in the power device, conditions that are merely reported to the controller, whereby the number and frequency of the events can be monitored. The second level of protection also provided by the diagnostic module may include power interlock to ensure that full power is being delivered to the integrated power module. The system permits detection of a transistor stack failure by monitoring the thermal resistance of the stack layers or junctions to detect physical degradation of the junctions and determine when the level of deterioration exceeds a pre-determined level. In addition, a power cycling failure diagnosis determines the integrity of the wirebonds, for example, wirebonds joining a silicon die to appropriate metal land patterns, as well as the integrity of stack junctions.