IC-SP-06027 R1
Note 2: The PWM frequency is approximated by the following equation:
PWM Frequency (in Hertz)
≅
0.494 / ( CTR x RTR )
Note: CTR is in Farads, RTR is in Ohms.
•
Please set the maximum frequency of PWM is 20KHz or less.
•
When the PWM frequency is set a high frequency, the switching loss is increased. And it
produces an increase in temperature of IC.
•
Please confirm the increased IC temperature with an actual set, and use it in the range of
derating curve.
Note 3: Attention of part setting of charge pump circuit
The following attention is necessary when used excluding the standard part.
•
When the voltage (Vcp) between C+ and C- is dropped, the gate voltage of top arm IGBTs is
dropped. And then the loss of IC increases. Vcp must not become Vcp<10V.
Capacitor
•
Vcp is dropped by the internal dissipation current from C+ terminal of IC, when capacity is
small.
•
The voltage impressed to the capacitor becomes VCC in operation. Therefore, the withstand
voltage of the capacitor is necessary more than the VCC voltage.
Diode
•
Forward voltage (VF) recommends the small one as much as possible. Because of, Vcp is
dropped when VF is large.
•
Reverse recovery time (trr) recommends the small one as much as possible. Because of,
Reverse recovery charge (Qrr) becomes large at charge pump operation when trr is large.
And then, VCP is drop.
•
The withstand voltage of the diode is needed more than the VS voltage because CL is
changed from about 0V to VS.
•
The rush current flows to diode D1 and D2 by charging with capacitor C1 and C2 when the
VCC power supply is turned on by VS=0V. Please select the ratings current of the diode in
consideration of this current.
Note 4: When the VB supply is used for the power supply of Hall ICs, please select Hall IC in
consideration of VB output current. The VB output current must be less than 25mA.
(2) Other external parts
•
Parts of Table 5-9 are recommended to be arranged to protect stabilization and IC of the power supply
from the voltage serge.
•
Please adjust the part setting according to usage conditions. And also, please set up each part close to
the terminal of IC to achieve the effect of the voltage serge absorption.
Table 5-9
Parts
Cvcc1
Cvcc2
ZDvcc
Cvs1
Cvs2
ZDvs
Purpose
for High frequency noise suppressing
for Vcc power supply smoothing
for Over voltage suppressing
for High frequency noise suppressing
for Vs power supply smoothing
for Over voltage suppressing
Remarks
Ceramic capacitor with good frequency response etc.
Electrolytic capacitor etc.
Zener diode with good frequency response etc.
Ceramic capacitor with good frequency response etc.
Electrolytic capacitor etc.
Zener diode with good frequency response etc.
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