The following figures show the schematic of the UCC23711 (U1) gate driver and the 1200V IGBT power module (Q1) used for testing and validation of the UCC23711.

Figure 3-1 UCC23711 Schematic Phase U Top Gate Driver Example

Figure 3-2 IGBT Module and DC Bus Schematic

A 1200V 6-pack IGBT power module Q1 in a 3-phase half bridge topology without a brake IGBT and with NTC was used. The IGBT module supports 25A continuous current and 50A peak current was used for the tests. The typical collector-emitter saturation voltage at 25°C is 1.6V at 15V across VGE and 25A current. The typical gate threshold voltage is 5.8V, the gate charge is 0.395µC at 600V and VGE=±15V, the internal gate resistor is typically 0Ω. When using a bipolar supply with 15V and -8V supply the corresponding gate charge is around 0.3µC, for a unipolar 15V supply is around 0.2µC. The gate charge impacts the bias supply power rating and decoupling caps. The turn-on delay time at 25°C is 35ns, the turn-off delay time is 190ns. This must be considered for the complementary PWM dead time setting.

In this design, the UCC23711 is selected due to the 6.5V DESAT threshold.