External Sc Protection Circuit With Using Three Shunt Resistors; Circuits Of Signal Input Terminals And Fo Terminal - Mitsubishi Electric PSS**S72FT Manual

Dual-in-line package intelligent power module
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<Dual-In-Line Package Intelligent Power Module>
1200V Mini DIPIPM with BSD Series APPLICATION NOTE

3.1.4 External SC Protection Circuit with Using Three Shunt Resistors

DIPIPM
Drive circuit
P-side IGBT
N-side IGBT
Drive circuit
Protection circuit
V
NC
CIN
A
Note:
(1) It is necessary to set the time constant R
SC interrupting time might vary with the wiring pattern, comparator speed and so on.
(2) The threshold voltage Vref should be set up the same rating of short circuit trip level (Vsc(ref) typ. 0.48V).
(3) Select the external shunt resistance so that SC trip-level is less than specified value.
(4) To avoid malfunction, the wiring A, B, C should be as short as possible.
(5) The point D at which the wiring to comparator is divided should be near the terminal of shunt resistor.
(6) OR output high level should be over 0.51V (=maximum Vsc(ref)).
(7) GND of Comparator, GND of Vref circuit and Cf should be not connected to power GND but to control GND wiring.

3.1.5 Circuits of Signal Input Terminals and Fo Terminal

(1) Internal Circuit of Control Input Terminals
DIPIPM is high-active input logic.
3.3kΩ(min) pull-down resistor is built-in each
input circuits of the DIPIPM as shown in
Fig.3-1-5 , so external pull-down resistor is not
needed.
Furthermore, by lowering the turn on and turn
off threshold value of input signal as shown in
Table 3-1-1, a direct coupling to 3V class
microcomputer or DSP becomes possible.
Table 3-1-1 Input threshold voltage ratings(Tj=25 °C )
Item
Turn-on threshold voltage
Turn-off threshold voltage
Note: The wiring of each input should be patterned as short as possible. And if the pattern is long and the
noise is imposed on the pattern, it may be effective to insert RC filter. There are limits for the minimum
input pulse width in the DIPIPM. The DIPIPM might make no response or delayed response, if the input
pulse width (both on and off) is shorter than the specified value. (Table 3-1-2)
Publication Date: September 2015
P
U
V
External protection circuit
W
C
NW
NV
NU
D
Shunt
resistors
N1
Fig.3-1-4 Interface circuit example
C
of external comparator input so that IGBT stop within 2μs when short circuit occurs.
f
f
U
、V
P
U
、V
N
Symbol
Condition
Vth(on)
U
,V
W
-V
P
P,
P
Vth(off)
U
,V
,W
-V
N
N
N
30
Comparators
(Open collector output type)
R
f
B
-
C
f
Vref
+
-
+
Vref
-
Vref
+
DIPIPM
、W
P
P
3.3kΩ(min)
、W
N
N
3.3kΩ(min)
Fig.3-1-5 Internal structure of control input terminals
Min.
-
terminals
NC
terminals
0.8
NC
5V
OR output
Level shift
Gate drive
circuit
circuit
Gate drive
circuit
Typ.
Max.
-
3.5
-
-
Unit
V

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