Application Note
28 of 53
V 1.0
2019-04-01
IM393 Application note
IM393 IPM Technical Description
Function and protection circuit
Input
Noise
filter
Input
Noise
filter
Deadtime &
Shoot-Through
Prevent ion
ITRIP
Noise
filter
HIN(X)
LI N(X)
COM
ITRIP
Noise
filter
VDD
Under-
voltage
detection
+3.3V
R
RCIN
C
RCIN
RFE
To Microcontroller
ITRIP
COM
LI N(X)
HIN(X)
Figure 18
Internal block diagram of IM393-XX
I
TRIP
LIN(U, V, W)
HIN(U, V, W)
T
FLT-CLR
50%
50%
U, V, W
50%
T
ITRIP
50%
RFE
50%
T
FLT
Figure 19
Input-output timing chart during short-circuit event
The T
FLT-CLR
can be determined by the below formula.
In the case of 3.3 V,
V
RFE
(t) = 3.3 V * (1 – e
-t/RC
)
(4)
T
FLT-CLR
= - R
RCIN
* C
RCIN
* ln (1-V
IN_TH+
/3.3 V)
(5)
For example, if R
RCIN
is 1.2 MΩ and C
RCIN
is 1 nF, the T
FLT-CLR
is about 1.7 ms with V
IN_TH+
of 2.5 V.