IC that counts time with 1/2 microsecond accuracy?

Discussion in 'General Electronics Chat' started by Razor Concepts, Apr 8, 2009.

  1. Razor Concepts

    Thread Starter Active Member

    Oct 7, 2008
    Is there some kind of IC that can count time with an accuracy of half of a microsecond? I don't really care how it communicates as long as I can read the time when I tell it to start counting and stop counting. Thanks!
  2. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
    Almost any MCU with a clock fast enough can do that. How much long term accuracy do you need?

  3. electronictech

    Active Member

    Apr 1, 2009
    I would suggest using a TTL counter(s) driven with a 2Mhz clock for half microsecond resolution. You can always increase the resolution by increasing the drive clock speed.

    You can also use a microcontroller that has a built in timer for this function, but you have to know how to initialize and activate the onboard timer.

    An easy to use TTL counter is the 7490 or 7492, which is a 4-bit counter. You can cascade these together to get the bit size needed for the total count you are looking to make. For clock speeds of 2MHz, 'LS' series logic should be fine....for really fast clock speeds use 'F' series or 'HC' series logic.
  4. KL7AJ

    Senior Member

    Nov 4, 2008
    One technique that can relax some of your requirements is to count several periods, if it's a repetitive waveform, and then divide by the number of waves to obtain the period.