TTL equivalent

Thread Starter

sparky3489

Joined Sep 21, 2009
12
Anybody know if a TTL equivalent exists for this CMOS device and if the ones I have found will work in the schematic?

Other suggestions welcome.

CD4063 = 74HCT85
CD4040 = 74HC4040
CD4001 = 74HC02
CD4069 = 74HC04
CD40110 = ?

 

Audioguru

Joined Dec 20, 2007
11,248
74HCxxxx is not TTL. It is high speed Cmos that needs a 2V to 5V supply.
I think the 74HC04 will melt in the CD4069 oscillator circuit.
 

jgessling

Joined Jul 31, 2009
82
For the CD40110 you may have to use two ttl chips. One 74LS90 for the counter outputting BCD to a 74LS47 to drive the displays. I'm just figuring out a similar thing so take this with a grain of salt. You can see how little the 74LS90 does so I suppose it made sense to combine the two functions into one chip.

Regards, Jim
 

bertus

Joined Apr 5, 2008
22,270
Hello,

A 74190 will do up and down counting, as a 7490 can only count up.
You will also need a latch like a 7477.
Then you will need a decoder for the display.
The type depends on the type of display used.

Greetings,
Bertus
 

Thread Starter

sparky3489

Joined Sep 21, 2009
12
WOW! Awesome responses.

It looks like the 40110 is a combination function chip.
40110 - Up/Down Counter-Latch-Decoder-Driver
I found that to be the case as well. Thanks for the links.

74HCxxxx is not TTL. It is high speed Cmos that needs a 2V to 5V supply.
I think the 74HC04 will melt in the CD4069 oscillator circuit.
I was afraid of that.

For the CD40110 you may have to use two ttl chips. One 74LS90 for the counter outputting BCD to a 74LS47 to drive the displays. I'm just figuring out a similar thing so take this with a grain of salt. You can see how little the 74LS90 does so I suppose it made sense to combine the two functions into one chip.
A 74190 will do up and down counting, as a 7490 can only count up.
You will also need a latch like a 7477.
Then you will need a decoder for the display.
The type depends on the type of display used.

It looks as though I may stick with the original design or go single chip with an AVR.

Thanks everyone.

P.S. This is the concept - http://carstereoforum.net/showthread.php?t=1229

The 8-bit to 7-segment was just a "bells and whislte" kind of thing.
 
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