MT6M15962a
3. Optocoupler peripheral circuits
© Fuji Electric Co., Ltd. All rights reserved.
3.1 Optocoupler for control input
3.1.1 Optocoupler rating
Use an optocoupler that satisfies the following characteristics.
• CMH = CML > 15kV/μs or 10kV/μs
• tpHL = tpLH < 0.8μs
• tpLH – tpHL = -0.4
～
0.9μs
• CTR > 15%
Example:
HCPL-4504 by Broadcom
TLP759 (IGM) by Toshiba
TLP2958 by Toshiba
PS9513 by Renesas Electronics
Pay attention to safety standards such as UL and VDE.
The reliability and characteristics of these optocouplers are not guaranteed by Fuji Electric.
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3.1.2 Primary side current limiting resistor
The current limiting resistor on the primary side should be selected so that sufficient current can flow
on the secondary side. Also, deterioration of CTR of the optocoupler over time should be considered in
the design of the current limiting resistor.
3.1.3 Wiring between optocoupler and IPM
The wiring distance between the optocoupler and the IPM should be short as much as possible to
reduce the wiring impedance. Make sure that the primary and secondary lines of the optocoupler are
not close together to reduce the floating capacitance. A high dv/dt is applied between the primary side
and the secondary side.
