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ISO1410: PWD parameter

Genius 9925 points

Replies: 2

Views: 33

Part Number: ISO1410

Hello,

My customer made a prototype with ISO1410 and measured PWD parameter in the receiver side of the ISO1410. 
Then they found it was 62nsec while the datasheet specifies this value as 12.5nsec MAX.

Then they have two questions.

1.
This 12.5nsec max in the datasheet is just max value if C_L is 15pF case. There is no issue for ISO1410 deivce itself.
If their system can accept this longer PWD, it's OK. Is this understanding correct?

2.
Does longer PWD mean that this board has bigger C_L than 15pF?

Regards,
Oba

  • Hi Oba,

    Thanks for reaching out. Could you please confirm that customer has followed the test setup shown in Figure 42 of ISO1410 datasheet for testing for receiver PWD? I am particularly referring to including 50Ω/54Ω resistance across the supply as shown in test setup.

    1. Yes, 12.5ns is the max receiver PWD for CL = 15pF. On a customer product, external components can influence this value to increase shouldn't be any issues for ISO1410 in any way. Your understanding is correct, higher PWDs do not cause any issue to device..
    2. Longer PWD can mean many things and one of them can be a higher CL (>15pF). If the bus rise and fall times are slow, then PWD can increase due to them as well.

    Regards,
    Koteshwar Rao

  • Oba,

    While unspecified in the datasheet for the PWD setup and parameters, the rise and fall time of VI should be 1ns to 2ns in order to obtain the same results as from the datasheet. Also please make sure your test setup also has CL = 15pF. 

     

    Respetfully,

    Lucas Schulte