• TI thinks resolved

TS3A4751: Bandwidth for TS3A4751

Part Number: TS3A4751

Dear Sir/Madam,

The bandwidth indicated in datasheet for TS3A4751 is 123MHz.

But it didn't mention whether it is at -3dB ?

However there is BW graph in datasheet shown below that at -3dB, the freq is about 70MHz.

Why the info is not tally ?

Thanks.

  • In reply to lee peng kiat:

    A logic buffer does not directly pass through the original signal, but generates a new signal that has the same logic state as the input. This means that you can improve on the original signal, e.g., by having faster edges or more drive strength.

    It does not make sense to speak about losses or Ron.

    A buffer has a higher propagation delay than a bus switch, but it's still only a few nanoseconds (depending on the logic family).

    Buffers have a very low output impedance, so it's possible to get ringing if the distances are large enough that you have transmission line effects. This can be prevented by terminating the line properly.
  • In reply to Clemens Ladisch:

    How to terminate properly for ringing prevention ?
    If the signal go through two or three buffer, the ringing will be worst than just go through a single buffer?
    What is the BW for SN74LVC126A, will it be reduced along the propagation due to trace length or other factors ?
    Thanks
  • In reply to lee peng kiat:

    "Bandwidth" is an analog specification; digital buffers have a maximum frequency.

    A buffer decouples its output from its input, so it tends to improve the signal.

    Ringing is a problem only if it is larger than the noise margin and causes the receiver to detect the wrong logic level.

    For possible termination mechanisms, see the AHC or LVC application notes (SCAA034, SCBA010).