MT6M15962a
2. Important remarks
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2.1 Control power supply units
A total of four isolated power supply units; three for the upper arm and one for the lower arm are
required as shown in the application circuit examples. Mount an aluminum electrolytic capacitor (upper
arm: approx.50V/10μF, lower arm: approx.50V/47μF
）
as close as possible to the control power
terminal
V
CC
of the IPM. This capacitor is not for smoothing the control power supply, but for
compensating the wiring impedance up to IPM. It is predicted that the use of only a single power supply
such as a bootstrap causes voltage fluctuations. Thus, careful consideration and verification are
required.
When using a commercially available power supply unit, do not use the output GND terminal of the
power supply unit. If the GND of the output side is connected to
the + or − terminals, it may cause a
malfunction because each power supply unit is connected to the power ground of input side.
Furthermore, reduce the stray capacitance (floating capacitance) between the power supply unit and
the GND as much as possible.
In addition, use a power supply unit with sufficient Icc supply capacity and reduce output voltage
fluctuations.
4-6
2.2 Structural insulation between four power supply units (input portion connector and PCB)
The four power supply units and the main power source have to be insulated from each other.
Be sure to secure a sufficient insulation distance because high dv/dt is applied to this insulation part
during IGBT switching. (2 mm or longer is recommended)
2.3 GND connection
Do not connect the control terminal GND U and the main terminal U, control terminal GND V and
main terminal V, control terminal GND W and main terminal W, control terminal GND and main
terminal N (N1 and N2 in the case of P631) to external circuits. In that case, it may cause a malfunction.
2.4 External capacitors for control power supply
Capacitors of 10μF (47μF) and 0.1μF connected to each power supply unit shown in typical
application circuits are not used for smoothing the output voltage of the power supply units, but for
compensating the wiring impedance from the power supply unit up to the IPM. Additional smoothing
capacitors are required. Furthermore, these external capacitors should be connected as close as
possible to the IPM control terminals or optocoupler terminals because transient fluctuation occurs in
the wiring impedance between these capacitors and the control circuits.
An electrolytic capacitor which has low impedance and good frequency characteristics is
recommended. In addition, it is recommended to connect a film capacitor with good frequency
characteristics in parallel.
