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LMH1981 Values

Other Parts Discussed in Thread: LMH1981

Dear Sir / Madam,

We have few questions regarding  to LMH1981

1 . In Datasheet, all timing Value(s) are Typical, no min. no Max.

      We would like to get Min and Max, or at least Max timing parameters.

       For example, we got series with TDhsout with delay in PAL 85ns instead 60ns (Room temperature, 24 Celsius)  

2. No timing Parameter for OEOUT (Even Odd) , this signal is very important to us.

     We measured OEOUT Delay:

    Old board: 588 ns

   New Board: 484 ns

   In old board date code is VM23AB

   In the new board date code is 41A57C

 

  The parameter for CS out Typical is 525ns , I guess it’s same parameter for OEOUT, so once we got 588ns

Other date code 484ns.

Please be so kind and advise if you can provide those figures.

BR,

Nir

  • Hello Nir,

    The LMH1981 production testing does not include timing specification limits testing and that is the reason why you cannot find min / max datasheet values. I asked to see if it is possible to know the worst case limits but I did not get an answer which could help you much in determining the expected variation.

    1. For "tdHSOUT" measurement:

    a) Did you take into account your probe / scope cable length / delay difference between the two probes (one probe on VIN and the other on tdHSout)? Are you monitoring both points "similarly" (with no additional delays in setup)?

    b) Is your VIN sync transition and HSOUT clean and distinct to use as reference?

    c) Are you applying the input similarly to Figure 2 (pin 4 AC coupled)?

    2. For OEout and CSout:

    a) How are you measuring these in Figure 3 and Figure 4?

    b) What is your reference point?

    Regards,

    Hooman