Go Down

Topic: True Fact: TI still manufactures the 74LS47 (Read 3187 times) previous topic - next topic

JoeN

Apr 26, 2014, 08:16 am Last Edit: Apr 26, 2014, 08:17 am by JoeN Reason: 1
(note:  The 7447 / 74LS47 is the famous BCD to 7 segment decoder IC that everyone should use at least once)

Not sure if this should go here, General Discussion, or Bar Sport, or perhaps nowhere.

I find it sort if interesting that TI still manufactures the 74LS47.  This chip was designed around 1974.  TI last updated their datasheet for it in 1988.  And it's an active part, you can get it at Digikey.  They just won't sample it to you.

I wonder why this chip needs to continue to be made.   Isn't it available in other families?  Is this still used in new designs or just old ones that have been hanging around since I was in high school?

http://www.ti.com/product/sn74ls47
I will never ask you to do anything that I wouldn't do myself.

fungus


I wonder why this chip needs to continue to be made.  


If they're still making it, it's because somebody's still buying it.  Simple as that.

People are selling them on eBay, too: http://www.ebay.com/sch/i.html?_nkw=74LS47
Advanced Arduino

JoeN


People are selling them on eBay, too: http://www.ebay.com/sch/i.html?_nkw=74LS47


I am entirely aware they are selling them on eBay.  Jameco too.  Those two sources are where I got the 40 or so of them that I own.  They are so darned useful!  :D
I will never ask you to do anything that I wouldn't do myself.

E40racer

May I ask what you are using them for? When I started out with Arduino I bought a whole bunch of 74xxxx IC's. But haven't done much with them.

Pelleplutt

I use CD4511, are more lowpower
(lowpower schottky are today rather highpower)

Pelle

Paul__B

Since the 74HC47 apparently exists, and therefore renders the "HC" version entirely obsolete.  But does not appear on eBay.

This would appear to be an "inertia" thing - minimal use in new designs (because you do not drive single 7-segment digits), so little demand, therefore price on HC version remains relatively high compared to an antique fab churning out LS.  Probably a significant demand for service replacements with people not realising that not only could they, but should replace automatically with the "HC".

TomGeorge

Hi, if you really want to know how old digital ICs  are for popularity, check the e14, farnell, RS and the like and see if they have the same chip available in smd and on a reel.
The use of some ICs is still needed for signal conditioning for later more modern ICs, so why reinvent the wheel, when hex inverter and schmitt trigger devices are still needed.
Long live, 4001, 4011, LM555, LM324, TL081 to 84, BC548  and family, I even have a couple of OC77 and OA92  somewhere.

Tom...... :)
Everything runs on smoke, let the smoke out, it stops running....

retrolefty

Well I would want to see the data code stamp on the chip for those still selling them before I would assume that TI is still actively manufacturing them, as many continue to sell NOS that they have in inventory. I would think a little searching on the TI web site(s) would answer if any specific flavor of the 74XX47 is still being manufactured by TI.


fungus


May I ask what you are using them for? When I started out with Arduino I bought a whole bunch of 74xxxx IC's. But haven't done much with them.


Do they have date codes on them?

What's the newest date code anybody can find?
Advanced Arduino

E40racer

I have 2 HD74LS74AP IC's. The only other marking they have is 1G16, which I assume is the date code? Not sure but I think I bought them from Tayda electronics.

JoeN


May I ask what you are using them for? When I started out with Arduino I bought a whole bunch of 74xxxx IC's. But haven't done much with them.


I started out doing stuff with 7400 ICs just prior to picking up Arduino.  I did a bunch of stuff, counters, adders, a multiplier using the 74284/74285, a text scroller using 16 segment displays, EEPROMs, and 7400 logic.  I wanted to know some of this basic stuff before working with microcontrollers.  Without any microcontroller in the design, these circuits are very useful to get data on a display.
I will never ask you to do anything that I wouldn't do myself.

CrossRoads

74ls47 is kind of pointless with a uC. Have to hold the inputs for it. Not daisychainable. Using shift register is a much better way to go. Daisychainable, mux-able.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

JoeN


74ls47 is kind of pointless with a uC. Have to hold the inputs for it. Not daisychainable. Using shift register is a much better way to go. Daisychainable, mux-able.


For serial register fans (I am one myself), TI apparently still also manufactures the also famous 164 and 165 in LS:

http://www.ti.com/product/sn74ls165a  
http://www.ti.com/product/sn74ls164
I will never ask you to do anything that I wouldn't do myself.

Go Up