In an IGBT, during the turn-on time

In an Insulated Gate Bipolar Transistor (IGBT), the turn-on time is a critical parameter for many applications, particularly in power electronics. The turn-on time of an IGBT is the period required for it to switch from the off state to the on state. This time is composed of two main segments: the delay time (td(on)) and the rise time (tr).

1. Delay Time (td(on)): This is the initial phase of the turn-on process. It starts from the application of the gate voltage until the collector current begins to rise. During this period, the gate capacitance is charged, but there is no significant change in the collector current. The delay time is influenced by the gate resistor value, the gate drive voltage, and the characteristics of the IGBT itself.

2. Rise Time (tr): Following the delay time, the rise time is the interval during which the collector current rises from 10% to 90% of its final value. This phase is characterized by the rapid increase in current flow as the IGBT transitions to its conducting state. During the rise time, the voltage across the IGBT drops, and the device starts conducting. The efficiency of this process is critical for minimizing switching losses.

The total turn-on time (ton) can be expressed as: (t_{on} = t_{d(on)} + t_{r}).

Factors Affecting Turn-On Time:

– **Gate Drive Voltage