Shift register chip to drive 7 Segment LED

Hi I would like to drive a 7 segment using a shift register and have tried 
74LS164 but it could not source enough current.
Can anyone recomend me some parts that can drive the 7 segment using serial. 
I have quite a few common cathode and anode LEDs and I would like to make 
used of them.

Thanks

Richard 

Hello Richard,


> Hi I would like to drive a 7 segment using a shift register and have tried 
> 74LS164 but it could not source enough current.
> Can anyone recomend me some parts that can drive the 7 segment using serial. 
> I have quite a few common cathode and anode LEDs and I would like to make 
> used of them.
> 

Have you tried the 74HC164? Or HCT if you need TTL interface? However, 
if you need more than 5mA per Segment you should use a buffer anyway. 
Either some big bus driver, a ULN chip or seven FETs.

Regards, Joerg

http://www.analogconsultants.com

I'd use a 74HC595.  It has an extra register, so you avoid glitching
the outputs while you shift in the data. It can also source enough
current for typical LEDs.

"Richard" <boxster@myrealbox.com.nospam> schrieb im Newsbeitrag
news:dsj6cv$38u$1@mawar.singnet.com.sg...
> Hi I would like to drive a 7 segment using a shift register and have tried
> 74LS164 but it could not source enough current.
> Can anyone recomend me some parts that can drive the 7 segment using
serial.
> I have quite a few common cathode and anode LEDs and I would like to make
> used of them.
>
> Thanks
>
> Richard
>
>

Use a TPIC6B595 from TI

http://focus.ti.com/docs/prod/folders/print/tpic6b595.html

or TPIC6c595 from TI

http://focus.ti.com/docs/prod/folders/print/tpic6c595.html

or from ST

http://www.st.com/stonline/products/literature/ds/7726/stpic6c595.pdf


MIKE

-- 
www.oho-elektronik.de
OHO-Elektronik
Michael Randelzhofer
FPGA und CPLD Mini Module
Klein aber oho !

Richard wrote:
> Hi I would like to drive a 7 segment using a shift register and have tried 
> 74LS164 but it could not source enough current.
> Can anyone recomend me some parts that can drive the 7 segment using serial. 
> I have quite a few common cathode and anode LEDs and I would like to make 
> used of them.
> 
> Thanks
> 
> Richard 
> 
> 

Try Alegro

Richard,

I am not sure why you elected to use the inferior drive 74LS variety but 
I have used the 74HC164 in smd to drive leds for an outdoor 32 segment 
bargraph. The problem you may facing is the type of display are you 
using. Chances are that it is probably very inefficient and you would be 
better off going to a high-efficiency display. I have run 7seg displays 
straight off I/O pins that are viewable in daylight without a problem, 
provided that you use high-efficiency/high-brightness displays.

But if you are trying to drive a large display (~1" and up) I guess you 
will need more drive than a poor little 164 can handle. Easiest way is 
just to couple the 164 to external drivers or use a more expensive and 
harder to get driver like the 5822 serial to parallel type.

But once again, as is common on newsgroups, the OP does not supply any 
helpful information or parameters on which to base a correct answer.

*Peter*

Richard wrote:
> Hi I would like to drive a 7 segment using a shift register and have tried 
> 74LS164 but it could not source enough current.
> Can anyone recomend me some parts that can drive the 7 segment using serial. 
> I have quite a few common cathode and anode LEDs and I would like to make 
> used of them.

I am using MAX7219 for driving LED displays.