Amplifying TTL Signal

Discussion in 'General Electronics Chat' started by Management, Dec 10, 2010.

  1. Management

    Thread Starter Active Member

    Sep 18, 2007
    306
    0
    Possible to amplify a TTL Signal coming out of a pulse generator? Out of the generator is 2.5V and I need 5V. The generator cannot go higher than 2.5V. :(

    I can only tolerate a 4ns rise time. Non-inverting amplification feasible? Any suggestions on fast enough op amps or discrete configuration?

    Thanks.
     
  2. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
    657
    Can you use a surface mount IC?
     
  3. Management

    Thread Starter Active Member

    Sep 18, 2007
    306
    0
    Yes that is an option.

    Thanks for the reply.
     
  4. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,754
    760
    Use High Speed Schmitt inverters at the output
     
  5. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    You could also use a CMOS 555, or some other CMOS gate.
     
  6. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    4nS rise time is very small. You'd require >= 500MHz bandwidth in an amplifier.
    1/4nS = 250MHz for an Av of 1; and you want an Av of 2.
    [eta]
    Oops, you'd need >= 1GHz GBW. 250MHz GBW would be -3dB; half-power point.

    There are no 555 timers that I know of that have such a high bandwidth.

    A high-speed video amplifier might work. However, the board design is going to be quite critical, along with the components used. You're basically dealing with RF signals here, and parasitics will rear their ugly heads.

    Input and output impedances will have to match.
     
    Last edited: Dec 11, 2010
  7. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
    657
    That's a good idea. It would be helpful if you could recommend an actual part number. I can't find rise and fall time specs for any TTL family.
     
  8. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
  9. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    I'd briefly considered the LT1016, but it's too slow (10nS vs 4nS) and the output voltage swing is not sufficient (~0.3v to ~3.4v with a 1mA load)
     
  10. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
    657
    LMV7219 is a comparator with rail-to-rail output and typical output transition times of 1.3nS.
    If you use it, set your input threshold voltage at approximately 1.25V.
     
Loading...