Connect with us

Quad buffer / line driver tri state circuit test rig

Discussion in 'General Electronics Discussion' started by Experimentalist, May 20, 2016.

Scroll to continue with content
  1. Experimentalist


    May 18, 2016

    Since nobody seems to have any suggestions regarding my other post Baffled - Please help - Quad buffer / line driver tri state circuit issue I am looking for guidance as to how I may be able to build a reliable test rig to test the 74HC125N channel by channel so that I can check my hardware.

    My chips are Phillips branded and have the following markings:

    BA427 01

    Currently I plan to power the chip at 3.3V between ground and VCC, tie the 3 unused "output enable inputs" to ground and use a 10K pull up on the "output enable input" for the channel under test. This will be the only component so I guess there is little point but I was going to put a 100nF decoupling capacitor as close as possible to VCC for good measure.

    What should I use for the data input and how can I reliably check the data output? I do now have an oscilloscope but virtually no experience using it as yet.

    I have attached the chip data sheet for reference.

    Any guidance gladly received.

    Attached Files:

  2. AnalogKid


    Jun 10, 2015
    The link in post #2 is to an intentionally incorrect circuit, not sure what it is supposed to teach the OP.

    OP - you don't say what you are testing for. Input transition levels, input currents, output voltage levels, output impedance, output currents, bandwidth, logical functions, etc. Also, are you trying for in-circuit testing, or are these stand-alone devices?

  3. Experimentalist


    May 18, 2016
    I am just trying to prove the devices function correctly. The whole issue is explained in my first post, also linked above. I am using the device to overcome a well known fault in another device where it does not tri state its MISO pin on the SPI bus. I think the SPI clock speed is 22MHz.

    I am trying to test it stand alone so as to understand the issue I explain in the other thread.
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day