DALI TX opto should have higher CTR?

Flyback

Well-Known Member
Hello,
Figure 5, page 3, of the following DALI application note (AN1465) shows optos being used to isolate both TX and RX DALI signals….

AN1465 Application note:
https://ww1.microchip.com/downloads/en/AppNotes/01465A.pdf

Though surely, the TX opto should be a TCLT1009 (CTR of TCLT1009 = 300%) and not a TCLT1000 (CTR of TCLT1000 = 50%)?

Also, surely the RX opto should be a TCLT1000, which it indeed is.

The reason that the RX opto should be a TCLT1000 is because it has a lower capacitance seen at its emitter pin which means the rise time of the emitter can be quicker. Do you agree?

TCLT100X opto datasheet:
https://www.vishay.com/docs/83515/tclt1000.pdf
 
Don't look like it would matter the TCLT1000 would work fine for both as shown.
 
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