Gate driver with VGTH and VCESAT measurement capability for the state of health monitor

A method of health monitoring for a circuit, comprising the steps of:

• connecting a collector of a first IGBT to an emitter of a second IGBT;
• turning on the first IGBT so as to operate the first IGBT in its forward linear region;
• turning on the second IGBT under test;
• adjusting the gate voltage of the first IGBT so as to change the collector current through the second IGBT;
• and
• measuring one or more collector-to-emitter voltage VCE values of the second IGBT;
• and
• determining a value of collector-to-emitter saturation voltage VCESAT, from the one or more VCE values in connection with determining a collector current value, for the second IGBT, that is substantially unresponsive to changes in VCE.

A computer-readable, non-transitory, programmable product, for use in conjunction with a digital demodulator comprising code for causing a processor to do the following:

• connect a collector of a first IGBT and an emitter of a second IGBT to a current source:
• turn on the first IGBT by causing it to operate in its forward region;
• turn on the second IGBT under test;
• adjust the gate voltage of the first IGBT;
• and
• cause a metering means to measure the collector-to-emitter saturation voltage VCESAT of the second IGBT.

An insulated gate bipolar transistor (IGBT) driver system on a driver module, including parameter monitoring capability, comprising:

• a first IGBT and a second IGBT, an emitter of the first IGBT, connected to a collector of the second IGBT;
• a first IGBT driver, for driving the first IGBT, and a second IGBT driver, for driving the second IGBT, each IGBT driver including a current source, a gate driver, and a pull-up switch connected to the gate driver;
• a processor;
• and
• a measurement device, connected to the processor, operable to measure IGBT collector-to-emitter saturation voltage in connection with a common channel current, between the first IGBT and the second IGBT, according to the control of the first IGBT operating in its forward linear active region.