Application Note
18 of 53
V 1.0
2019-04-01
IM393 Application note
IM393 IPM Technical Description
Interface circuit and layout guide
HIN
LIN
CIPOS
TM
Tiny
Gate driver
Gate driver
Input
Noise
Filter
Input
Noise
Filter
Deadtime &
Shoot
Through
Prevention
Delay
Level shift
circuit
Ω
≈
k
4
Ω
≈
k
4
Figure 11
Internal structure of signal input terminals
Because IM393-XX employs active-high input logic, the power sequence restriction between the control supply
and the input signal during start-up or shut-down operation does not exist. Therefore it makes the system fail-
safe. In addition, pull-down resistors are built into each input circuit. This reduces the required external
component count. Input Schmitt-trigger, noise filter, deadtime and shoot-through prevention functions
provide beneficial noise rejection to short input pulses. Furthermore, by lowering the turn ON and turn OFF
threshold voltage of the input signal as shown in Table 4.2, a direct connection to 3.3 V-class microcontroller or
DSP is possible.
Table 5
Input threshold voltage (at V
DD
= 15 V and T
J
= 25
°
C)
Item
Symbol
Condition
Min.
Typ.
Max.
Unit
Logic "1" input voltage
V
IN,TH+
LIN, HIN, RFE
2.5
-
-
V
Logic "0" input voltage
V
IN,TH-
-
-
0.8
V
As shown in Figure 11, IM393-XX input signal integrates a 4 kΩ (typical) pull-down resistor. Therefore, when
using an external filtering resistor between the microcontroller output and IM393-XX input, attention should be
paid to the signal voltage drop at the IPM input terminal to satisfy the turn ON threshold voltage requirement.
For instance, R = 100
Ω
and C = 1 nF for the parts shown in Figure 10.