8bit shift register with latch style setup?

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bh00

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Hey,

I might be being stupid or something, but is there one chip or a few chips that would emulate the circuit in the attachment?

Basically its some sort of shift register setup I'm looking for, using only two output ports so that I can use one for data and one for clock and once I've clocked 8 bits of data it latches it to the real outputs? I was looking at some 4000 series datasheets but nothing obvious. Would be stupid to be using that many D-type chips.

Thanks
 

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The CD4034 should do what you want. It accepts serial or parallel input and outputs to one of two 8 bit busses.
 
Hmm quite a large chip and can't seem to find it in stock at Rapid. Is there anything more easily available? I don't mind two chips if absolutely necessary. I might be able to do away with the counter and scrounge an extra clock pin off the microcontroller if necessary.
 
74HC595 from TI and others is what you want. The HC part may have several cousins in othe logic families that will be of interest.
 
If you need to drive some heavy loads you might want to look at Micrel MIC5821 or MIC5841 serial-to-parallel 8-bit sinking drivers... They also have a cascadable 3-pin interface (Data-In, Clock, Strobe, and Data-Out) and can sink several hundred milliamps... The Allegro A6821 and A6841 are similar devices...

Kind regards, Mike
 
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A CD4094B will do the shift and store. It will not sink or source very much current. This whole series of chips is kind of obsolete now and the number of suppliers is diminishing. Something to keep in mind if you plan to build any quantity.
 
there are two chips you can use to do exactly the same thing. You need a shift register (74HCT164 for example), and you need a counter with an enable pin. A cmos 4017 counter will do the trick.
 
Wait, are you saying the normal 4000 series of chips are dying out? CMOS stuff? What are they being replaced by?
 
Papabravo said:
A CD4094B will do the shift and store. It will not sink or source very much current. This whole series of chips is kind of obsolete now and the number of suppliers is diminishing. Something to keep in mind if you plan to build any quantity.
Click to expand...

Yea, it seems lots of TTL is starting to vanish too

74246 7446 scarce.
 
If you are familiar with th CPLDs you can implement the whole curcuit in single CPLD,you can chose the CPLD from any manufactuer such as Cypress,Lattice Semiconductors or Xilinx..Best wishes

K Daniel
 
The CPLD is only a viable solution for the logic function. If you are tyring to duplicate the wide Vdd range (3-18V), or the ultra low power consumption, then CPLDs won't be much good. On the other hand they are blazingly fast, and they may require a separate programmer.
 
Hrm not quite sure what happened to my earlier post...

Anyway I think I will go the 4094 route, even if they're apparently dying I'm sure I'll be able to get hold of some for a time to come.

Would a transistor array such as the ULN2803 be suitable to connect to the outputs of the latches and then drive small relays or some LEDs or something?

Also, cascading 4094s is done just by connecting data out on the first chip to data in on the next one, and so forth, and then connecting clock and strobes all to two common microcontroller outputs so they are all strobed or clocked together?

Thanks
 
Hi
If you are going to use the shift register to drive LEDs you can use one of the TOSHIBA LED driver ICs which have build in transister driver such as the TB62725BPG you can get the data sheet from the following web address

**broken link removed**
 
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