5-7. Dead time
(Applicable model: ECN30611, ECN30601, ECN30603, ECN30604)
Since this IC has an output of consisting of a totem pole of IGBTs, the IC may get destroyed when the top
and bottom arm IGBTs of the same phase are turned on simultaneously. Therefore, allow for an internal
delay of the IC and determine a dead time.
Here is how the dead time (TDI) of the input pin in the IC relates to the dead time (TDO) of the output pin.
TDO = TDI - TdOFF + TdON --------------------- (1)
TdON: Turn-on delay
TdOFF: Turn-off delay
To prevent the simultaneous turning-on of the top and bottom arms, the TDO should be set to more than
From Equation (1), TDI > TdOFF - TdON is the required setting condition of the dead time TDI. The worst
case is when the TdOFF is maximum or TdON is minimum.
The TdON and TdOFF have temperature-dependency (see Fig. 5-14 to Fig. 5-15). These should be
considered as well.
The above discussion does not allow for the effects of the populated board wiring and other elements. In
practice, please monitor the power supply current and other factors, and check that the top and the
bottom arm IGBTs of the same phase are not turned on simultaneously.
Dead time TDI > TdOFFT - TdONB
Dead time TDI > TdOFFB - TdONT
Fig. 5-13. Typical dead time settings