User guide
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Revision 1.4
2021-09-10
EVAL-M1-IM818-A user guide
Evaluation power board with MADK M1 connector
System and functional description
2.6.3.2
PWM shut down and GK output
When over-current is detected, the ITRIP voltage is over the threshold value, then C30 will be discharged (GK
is open drain), and GK drops to “0”. This GK sends signal to control board via J3. GK “0” status is continuous
for about 150 µs. After 150 µs, GK becomes open drain and charges C30 via R20. The R20 and C30 time
constant is about 470 µs. Figure 16 shows the ITRIP and GK circuit.
Figure 16
ITRIP & GK and fault-clear
2.6.4
NTC thermistor characteristics and over-heat protection calculation
This is NTC measurement circuit for EVAL-M1-101T as shown in Figure 12.
Figure 17
NTC (inside IM818 IPM) connect to EVAL-M1-101T via J3
The NTC is 85 kΩ @ TNTC = 25°C, B-constant = 4092 K:
Figure 18
NTC temperature curve and table
