1ED020I12FA Datasheet, PDF (7/22 Pages) Infineon Technologies AG – Single IGBT Driver IC

2.5
External Protection Features
2.5.1
Desaturation Protection
A desaturation protection ensures the protection of the IGBT
at short circuit. When the DESAT voltage goes up and
reaches 9V, the output is driven low. Further, the FAULT
output is activated until it is cleared by /RST. A
programmable blanking time is used to allow enough time
for IGBT saturation. Blanking time is provided by a highly
precise internal current source and an external capacitor.
2.5.2
Active Miller Clamping
A Miller clamp allows sinking the Miller current during a
high dV/dt situation. Therefore, the use of a negative supply
voltage can be avoided in many applications. During turn-
off, the gate voltage is monitored and the clamp output is
activated when the gate voltage goes below 2V (related to
VEE2). The clamp is designed for a Miller current up to 1A.
2.5.3
Short Circuit Clamping
During short circuit the IGBTs gate voltage tends to rise
because of the feedback via the Miller capacitance. An
additional protection circuit connected to OUT and CLAMP
limits this voltage to a value slightly higher than the supply
voltage. A current of maximum 500 mA for 10us may be fed
back to the supply through one of this paths. If higher
currents are expected or a tighter clamping is desired external
Schottky diodes may be added.
2.6
RESET
The reset input has two functions.
Firstly, /RST is in charge of setting back the FAULT output.
If /RST is low longer than a given time , /FLT will be reseted
at the rising edge of /RST; otherwise, it will remain
unchanged. Moreover, it works as enable/shutdown of the
input logic.
EICEDRIVER®
1ED020I12FA
Datasheet
7
Version 2.1, 2009-11-24