Patent ID: 7817392

Claim:
An Insulated Gate Bipolar Transistor (IGBT) fault protection system comprising: a Gate Voltage Pattern Analyzer (GVPA) configured to analyze a gate voltage pattern of an IGBT to determine whether or not a fault has occurred, wherein the GVPA comprises: a first comparator configured to determine whether or not a short-circuit fault of the IGBT has occurred; and a second comparator configured to determine whether or not a fault under load of the IGBT has occurred; a gate voltage clamper configured to prevent a substantial increase in a gate voltage of the IGBT according to an output signal that the GVPA outputs when a fault has occurred; and a soft-off unit configured to softly turn off the IGBT according to a GVPA output signal that the GVPA outputs when a fault has occurred; wherein the fault protection system is implemented in an integrated circuit; a buffer and a resistor, coupled between a gate driver and a gate of the IGBT; a first terminal between the resistor and the gate, coupled to a non-inverting terminal of the first comparator; and a second terminal between the buffer and the resistor, coupled via a first and a second resistor to an inverting terminal of the first comparator; wherein the second terminal is coupled to an inverting terminal of the second comparator; and the first terminal is coupled via a third and a fourth resistor to a non-inverting terminal of the second comparator.