Technical Explanation
SKiiP
®
4 F-Option Board
© by SEMIKRON
2017-08-30 - Rev02
14 / 21
10 Optical Input/Output Signals
10.1
PWM TOP/BOT Signals
The PWM TOP/BOT optical signals could be described as follow: by recognised incoming light the IGBT will be
switched on, by no light the IGBTwill be switched off. Please see Table 4.
Table 4: PWM TOP/BOT optical signals
Optical Receiver receives light
Optical Receiver receives no light
IGBT ON
IGBT OFF
Please note:
A non-connected optical link will be considered as LOW signal (IGBT OFF).
If the light intensity is not sufficient the IGBT might stay off and an ERROR_OUT signal might be set. To avoid
this the minimal transmitter current I
Fdc
at the controller side should be at least 50 mA. Please see Figure 10.1
for example of the circuit for transmitter LED at the controller side.
Figure 10.1:Transmitter current controller side
