Building a 3:8 decoder with tristate outputs

  • Thread starter Thread starter Bipolarity
  • Start date Start date
  • Tags Tags
    Building Decoder
AI Thread Summary
A user seeks to modify a 3:8 decoder to achieve tristate outputs, allowing unused outputs to be high impedance. The suggestion is made to use tri-state buffers on the outputs of the decoder for this purpose. The user confirms they adopted this approach after learning about tri-state buffers. Recommendations for specific tri-state buffer models include the '245 and '240, with options for slow and fast CMOS variants. The discussion emphasizes practical solutions for achieving tristate functionality in decoders.
Bipolarity
Messages
773
Reaction score
2
So all my 3:8 decoders have outputs only at 1 and 0. I need a tristate decoder that can be configured so that the unused outputs are open circuits (i.e. high impedance).

I know how to build a 3:8 decoder (using logic gates). How might I go about modifying it so that it has tristate outputs? Is this possible?

BiP
 
Engineering news on Phys.org
Bipolarity said:
So all my 3:8 decoders have outputs only at 1 and 0. I need a tristate decoder that can be configured so that the unused outputs are open circuits (i.e. high impedance).

I know how to build a 3:8 decoder (using logic gates). How might I go about modifying it so that it has tristate outputs? Is this possible?

BiP

Would be easier to just put Tri-State buffers on the 8 outputs of the decoder, no? Or is your goal to build up the 3:8 decoder circuit to learn about it?
 
berkeman said:
Would be easier to just put Tri-State buffers on the 8 outputs of the decoder, no? Or is your goal to build up the 3:8 decoder circuit to learn about it?

Thanks! That's actually what I ended up doing once I learned about the tri-state buffer. Do you happen to know the datasheets for the tri-state buffer?

BiP
 
Bipolarity said:
Thanks! That's actually what I ended up doing once I learned about the tri-state buffer. Do you happen to know the datasheets for the tri-state buffer?

BiP

The '245 and '240 I think are octal Tri-State buffers. If you want slow CMOS, that would be the 74HC240 and 74HC245. If you want fast CMOS, that would be the AC or VHC families...
 
Hi all I have some confusion about piezoelectrical sensors combination. If i have three acoustic piezoelectrical sensors (with same receive sensitivity in dB ref V/1uPa) placed at specific distance, these sensors receive acoustic signal from a sound source placed at far field distance (Plane Wave) and from broadside. I receive output of these sensors through individual preamplifiers, add them through hardware like summer circuit adder or in software after digitization and in this way got an...
I have recently moved into a new (rather ancient) house and had a few trips of my Residual Current breaker. I dug out my old Socket tester which tell me the three pins are correct. But then the Red warning light tells me my socket(s) fail the loop test. I never had this before but my last house had an overhead supply with no Earth from the company. The tester said "get this checked" and the man said the (high but not ridiculous) earth resistance was acceptable. I stuck a new copper earth...
Thread 'Beauty of old electrical and measuring things, etc.'
Even as a kid, I saw beauty in old devices. That made me want to understand how they worked. I had lots of old things that I keep and now reviving. Old things need to work to see the beauty. Here's what I've done so far. Two views of the gadgets shelves and my small work space: Here's a close up look at the meters, gauges and other measuring things: This is what I think of as surface-mount electrical components and wiring. The components are very old and shows how...
Back
Top