Lower arms
control input
c6
c7
Protection
circuit state
SET
RESET
Internal IGBT
Gate-Emitter Voltage
c4
c3
c2
SC
c1
c8
Output Current
SC Reference Voltage
Sensing Voltage
of the shunt
resistance
CR circuit time
constant delay
c5
Fault Output Signal
(with the external shunt resistance and CR connection)
c1 : Normal operation: IGBT ON and carrying current.
c2 : Short circuit current detection (SC trigger).
c3 : Hard IGBT gate interrupt.
c4 : IGBT turns OFF.
c5 : Fault output timer operation starts: The pulse width of the fault output signal is set by the external capacitor CFO
c6 : Input “L” : IGBT OFF state.
.
c7 : Input “H”: IGBT ON state, but during the active period of fault output the IGBT doesn’t turn ON.
c8 : IGBT OFF state
Figure 10. Short-Circuit Current Protection (Low-side Operation only)
11
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FSBB30CH60C Rev. D
FAIRCHILD [ FAIRCHILD SEMICONDUCTOR ]
