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ISOM8113: Ton and Toff times switched in datasheet

franziskus
Expert 8369 points
Part Number: ISOM8113

Tool/software:

Hi,

page 9 in datasheet, chapter 6.8 seems to have errors. It looks like the times for Ton and Toff in the upper block are switched.

Also, test conditions seem to vary for both cases.

Can you confirm this?

BR

  • 0
    TI__Genius 17825 points

    Hello,

    Thanks for reaching out. 

    Please allow us an additional day to review and respond.

    Regards,
    Aaditya V

  • +1 in reply to Aaditya V.
    TI__Mastermind 29615 points

    Hello Franziskus, 

    I can confirm that the datasheet table is correct as is. The TON and TOFF times for the first condition is where the ISOM811x is in active mode (where IF < CTR * IC_max).

    The other test conditions are for saturation mode where IF >> CTR * IC_max. In saturation mode the output will drive be driven to the maximum output allowed by the output (usually set by a resistor) allowing for faster switching times. Other test conditions after this will use higher IF inputs and drive the output quicker to the saturation value. 

    Best,
    Andrew

  • 0 in reply to Andrew J
    TI__Expert 8369 points

    Thank you Andrew! The explanation of the test conditions is helpful.

    My customer is still confused about the Ton and Toff timings in the upper section.
    The numbers range would better match the way they are color coded (blue color for Toff).

    Is this difference intentional for active mode vs saturation mode?

  • +1 in reply to franziskus
    TI__Mastermind 29615 points

    Yes, the difference is due to performance differences between active vs saturation mode. In active mode, the output does not return to 0V. Also, the (theoretical) fastest possible switching time (TON+TOFF) is better for saturation mode (IF=1.6mA) then the active mode spec (Ic=2mA).

    Faster rise and fall times are achieved at higher input currents (IF=16mA).