SCM1200MF Datasheet, PDF (31/60 Pages) Sanken electric – 500V / 600V High Voltage Three-phase Motor Driver ICs

SCM1200MF Series
13. Design Notes
This section also employs the terminal notation
system for pin names, described in the beginning of the
previous section.
13.1. PCB Pattern Layout
Figure 13-1 shows a schematic diagram of a motor
driver circuit. The motor driver circuit consists of
current paths carrying high frequencies and high
voltages, which also bring about negative influences on
IC operation, noise interference, and power dissipation.
Therefore, PCB trace layouts and component
placements play an important role in circuit designing.
Current loops which carry high frequencies and high
voltages should be as small and wide as you can, in
order to maintain a low-impedance state.
In addition, ground traces should be as wide and short
as possible so that radiated EMI levels can be reduced.
U1
VBB ₂₅
V_DC
MIC3
MIC2
W ²⁶
27
LS3
29
V
LS2 ³⁰
Ground traces
should be wide
and short.
M
MIC1
U ³²
LS1 ³³
High-frequency, high-voltage
current loops should be as
small and wide as possible.
Figure 13-1. High-frequency, high-voltage current
paths
13.2. Heatsink Mounting Considerations
This section provides the guidelines for mounting a
heatsink, as follows:
● It is recommended to use a pair of a metric screw of
M3 and a plain washer of 7 mm (φ).
Use a torque screwdriver to tighten the screws.
Tighten the two screws firstly up to about 30% of the
maximum screw torque; then finally up to 100% of
the prescribed maximum screw torque. Perform
appropriate tightening within the range of screw
torque defined in Section 4.
● When mounting a heatsink, it is recommended to use
silicone greases.
If a thermally-conductive sheet or an electrically
insulating sheet is used, package cracks may be
occured due to creases at screw tightening. Therefore,
thorough evaluations should be conducted before
using these materials.
● When applying a silicon grease, there must be no
foreign substances between the IC and a heatsink.
Extreme care should be taken not to apply a silicon
grease onto any device pins as much as possible. The
following requirements must be met for proper grease
application:
 Grease thickness: 100 µm
 Heatsink flatness: ±100 µm
 When applying a silicon grease to a heatsink, it
should be applied within the area indicated in
Figure 13-2, below.
Screw hole
Screw hole
5.8
Thermal silicone grease
5.8
M3
application area
M3
Heatsink
37.6
3.1
3.1
Unit: mm
Figure 13-2. Recommended application area for
thermal silicone grease
13.3. IC Characteristics Measurement
Considerations
When measuring the breakdown voltage and/or
leakage current of the transistors incorporated in the IC,
the gate and emitter of each transistor should have the
same potential.
Moreover, care should be taken because the collectors
are all internally connected to the VBB pin.
The output (U, V, and W) pins are connected to the
emitters of the corresponding high-side transistors; and
the LSx pins are connected to the emitters of the
low-side transistors. The gates of the high-side
transistors are pulled down to the output (U, V, W) pins;
similarly, the gates of the low-side transistors are pulled
down to the COMx pins.
Note that the output, LS, and COMx pins must be
connected appropriately before measuring breakdown
voltage and/or leak current. Otherwise the switching
transistors may result in permanent damage.
The figures below are the schematic circuit diagrams
of a typical measurement circuit for breakdown voltage:
Figure 13-3 shows the high-side transistor (Q_1H) in U
SCM1200MF-DSJ Rev.1.1
SANKEN ELECTRIC CO.,LTD.
31
Feb. 19, 2016
http://www.sanken-ele.co.jp/en
© SANKEN ELECTRIC CO.,LTD. 2015