Fault protection testing in a high-power switching system

A method for testing a power system comprising:

• receiving a first test signal at a test terminal of a gate driver to begin a first test;
• configuring, during the first test, a power transistor in an OFF condition;
• charging, by a desaturation fault detection circuit of the gate driver, a voltage of a blanking capacitor, the blanking capacitor coupled externally to the gate driver at a desaturation terminal of the gate driver;
• comparing, by the desaturation fault detection circuit, the voltage of the blanking capacitor to a threshold to generate a fault signal;
• determining that the first test has passed or failed based on the fault signal;
• and
• performing a second test based on the first test being passed, the second test including:
• configuring, during the second test, the power transistor in an ON condition.

A gate driver comprising:

• a driver circuit configured to:
• drive a power transistor coupled to the gate driver in an OFF condition in response to a first test signal;
• and
• drive the power transistor coupled to the gate driver in an ON condition in response to a second test signal;
• and
• a desaturation fault detection circuit configured to:
• charge, in response to the first test signal, a blanking capacitor coupled to a desaturation terminal of the gate driver;
• detect, during a first test period, that a voltage of the blanking capacitor satisfies a fault condition to determine that the blanking capacitor is operating properly;
• not charge, in response to the second test signal, the blanking capacitor;
• and
• detect, during a second test period, that the voltage of the blanking capacitor does not satisfy the fault condition to determine that the power transistor is operating properly.