<Dual-In-Line Package Intelligent Power Module>
1200V Mini DIPIPM with BSD Series APPLICATION NOTE
Publication Date: September 2015
35
3.1.8 Precaution for Wiring on PCB
Fig.3-1-13 Precaution for wiring on PCB
The case example of trouble due to PCB pattern
Case example
Matter of trouble
•Control GND pattern overlaps
power GND pattern.
The surge, generated by the wiring pattern and di/dt of noncontiguous big
current flows to power GND, transfers to control GND pattern. It causes the
control GND level fluctuation, so that the input signal based on the control
GND fluctuates too. Then the arm short might occur.
•Ground loop pattern exists.
Stray current flows to GND loop pattern, so that the control GND level and
input signal level (based on the GND) fluctuates. Then the arm short might
occur.
•Large inductance of wiring
between N and N1 terminal
Long wiring pattern has big parasitic inductance and generates high surge
when switching. This surge causes the matter as below.
•HVIC malfunction due to VS voltage (output terminal potential) dropping
excessively.
•LVIC surge destruction
Capacitors or zener diodes are
nothing or located far from the
terminals.
IC surge destruction or malfunction might occur.
The input lines are located parallel
and close to the floating supply
lines for P-side drive.
Cross talk noise might be transferred through the capacitance between
these floating supply lines and input lines to DIPIPM. Then incorrect signals
are input to DIPIPM input, and arm short (short circuit) might occur.
4
2
1
3
N1
P
CIN
V
N1
,V
P1
UP,VP,WP
V
NC
,V
PC
UN,VN,WN
V
UFB
,V
VFB
,V
WFB
1
2
NU
NV
NW
Control
GND
Output
(to motor)
Power GND
Vin
+15V
Power supply
3
It is recommended to
connect control GND and
power GND at only a point
N1. (Not connect common
broad pattern)
Connect CIN filter's
capacitor to control GND
(not to Power GND)
Snubber
capacitor
4
Wiring to CIN terminal
should be divided at near
shunt resistor terminal and
as short as possible.
Locate snubber
capacitor between
P and N1 and as
near by terminals
as possible
Shunt
resistor
Wiring between NU, NV, NW
and shunt resistor should be
as short as possible.
Floating control supply V
*FB
and V
*FS
wire potential fluctuates between Vcc and
GND potential at switching, so it may cause malfunction if wires for control
(e.g. control input Vin, control supply) are located near by or cross these wires.
Particularly pay attention when using multi layered PCB.
Capacitor and
Zener diode
should be located
at near terminals
Control
GND
V
UFS
,V
VFS
,V
WFS
U
V
W
CFO