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ISO7821: vs ISO7821F

Part Number: ISO7821


I have been reading the datasheet and I cannot completely understand de differences between the ISO7821 and the ISO7821F. As I understand the F is used for fast propagation on low output and the other one for high output. But are there any other considerations that should be taken into account when chose one over the other?

thanks a lot,

  • Werner,

    The primary difference between the "F" and "non-F" devices is simply the default output state when the input state is open or indeterminate. The table above describes the conditions in which the default output state takes effect. One would choose which device has the best default state for their system.



  • Hi Werner,

    The primary difference between the devices ISO7821 and ISO7821F is the default state as also described in the function table of ISO78xx datasheet shown below. ISO7821 has a default HIGH output while ISO7821F has a default LOW output. The below table describes when is the output expected to go to the default state. Apart from this, there are no other major differences. Thanks.

    Koteshwar Rao