LED sink driver and Arduino question.?

Hi ... I would like to ask, if I can use 2 of these LED sink drivers uk.farnell.com/jsp/search/productdetail.jsp by using/controlling them just from 3 pins on my Arduino ???

I think, that it should be possible thanks to the pin22 SDO (datasheet www.farnell.com/datasheets/456099.pdf) ... what do you think ???

If yes, is there any limitation on HOW MANY shift registers/LED drivers you can connect "in a row" by using just 3 pins on Arduino ??? Could I use 4 of these drivers and control them just by 3 pins on Arduino ???

Thank you in advance for your answers...zholy

There's a limit, but it will be pretty large ! If you're worried, buffer the CLK and CS line with a 74HC125 or something like it - its good practice to keep the edges of the clock nice and clean, improves isolation, and helps reliable clocking.

I'd guess, without looking at the input current spec of the device you spotted,you could easily drive 8 or more without additional buffering. The Arduino has fairly strong output drive capability.