CTR of opto-coupler at low diode current (IF)?

[eem2am]

Hello,

Can i please confirm that even though the CNY17-2 opto-coupler has a stated CTR of 63% to 125%, .....this does not apply at all levels of diode current?

For example ,Figure 5, page 5 appears to show that the CTR of CNY17-2 is just 30% at a diode current (IF) of 500uA ?

So do you agree that at low diode currents, the stated "63% to 125%" CTR is meaningless?


CNY17-2 DATASHEET:
http://www.vishay.com/docs/83606/cny17.pdf

 

[Laplace]

The stated 63% to 125% CTR applies only to a single point on the graph in Figure 5. The graph shows that at If=10mA the CTR is 95%, but it could be as low as 63% or as high as 125%. The graph also shows that the CTR is significantly less at reduced diode current.