Hi guys, currently working on a small project.
I'm looking for a driver/decoder to drive 4 common cathod 7segment display?
Is it possible to use 74LS47?..if not, any recommendation what driver to use?
perheps can show me the circuit as well...
thanks guys..

I don't know driver IC for common cathode display in LS-serie, but in difficult situation use the shunt-methode.The outputs are open-collector so when saturated, the segment not lit. Also need inverting the BCD inputs. Another way: additional PNP transistors for each segment output...
So i recommend to buy a common anode display, it's cheaper.

You could use open collector inverters but it's much simpler
to obtain 74LS48 instead of 74LS47.

You can use a 74LS48, but remember that is it open collector, therefore you must tie resistors from each segment to +5v instead of series resistors as with the 74LS47. A 7 sip style resistor network works great, it can be placed along side the 74LS48 connecting from pins 9-16, just watch for the pin 1 mark on the sip and make sure it connects to pin 16 of the 74LS48. A resistor value of 150 ohms works well for high efficiency displays.

Actually 7447 has open colelctor, 7448 has pullup resistor built in.
Check the lower right schematic ('48 output)

Yes you are correct, technically the 74LS48 is not open collector, however the 2 k pullup is useless to supply drive current to an led display ( very dim, and as far a drive current goes I consider it equivalent to o/c) the use of the sip I mentioned gives sufficient current for a viewable display.

Just for arguement sake, the on chip 2k pullup resistor will give a drive current of : 5v(vcc) -1.6v (assumed display forward voltage)/2000 ohms = 0.00156A or 1.56mA , you see, not much for driving a display. It gets even worse if you use a display with a higher forward voltage such as green ,yellow, or blue.

The use of a 330 ohm sip will render a drive current of about 12 mA.
( assuming a 1.6v display forward voltage and taking the 2k on chip pullup into account ).