Q.Describe the output VI characteristics of IGBT.

The output characteristics of an IGBT plot collector current $I_C$ against collector-emitter voltage $V_{CE}$ for a family of gate-emitter voltages $V_{GE}$; they resemble a BJT's but are controlled by $V_{GE}$. …

[!TLDR]

Plot $I_C$ vs $V_{CE}$ for increasing $V_{GE}$: cut-off, active and saturation regions, like a BJT but controlled by the gate-emitter voltage.

The insulated-gate bipolar transistor (IGBT) combines the high-input-impedance voltage-controlled gate of a MOSFET with the low on-state drop of a BJT. Its output characteristics show the collector current $I_C$ as a function of the collector-emitter voltage $V_{CE}$, drawn as a family of curves for increasing values of the gate-emitter voltage $V_{GE}$. They are qualitatively similar to a BJT's output characteristics, except that the controlling parameter is the gate-emitter voltage rather than a base current.

The regions are:

• Cut-off region: when $V_{GE}$ is below the threshold voltage $V_{GE(th)}$, only a very small leakage current flows and the IGBT is OFF.
• Active region: when $V_{GE}$ is above $V_{GE(th)}$, collector current flows and is controlled by $V_{GE}$; the collector-emitter voltage is set by the load line. …