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IRS2608DSPbF

A common problem in today’s high-power switching converters is the transient response of the switch node’s voltage as

the power switches transition on and off quickly while carrying a large current. A typical 3-phase inverter circuit is

shown in Figure 10; here we define the power switches and diodes of the inverter.

If the high-side switch (e.g., the IGBT Q1 in Figures 11 and 12) switches off, while the U phase current is flowing to an

inductive load, a current commutation occurs from high-side switch (Q1) to the diode (D2) in parallel with the low-side

the negative DC bus voltage.

Figure 10: Three phase inverter

Q1

ON

D2

Q2

OFF

DC+ BUS

DC- BUS

Figure 11: Q1 conducting

Figure 12: D2 conducting

Also when the V phase current flows from the inductive load back to the inverter (see Figures 13 and 14), and Q4 IGBT

the positive DC bus voltage to the negative DC bus voltage.