I didn't know that you could do that, but after talking to a friend of  
mine about it is certainly an option. He as done this before... My  
only doubt is how do you make sure the gates are current sharing  
properly?
What it really anoys me is the datasheets, they are so misleading,  
After closer inspection, Russell is completly correct, the 40mA rating  
is for one gate only on and for a small amount of time!!! For a steady  
state you have 12mA.
Why do they need to do that?

Thank you for all the help, I will consider stacking, but I also need  
to change the current limiting resistors.

Best Regards
                       Luis

Sent from my iPhone

On 18 May 2010, at 18:27, "Bob Blick" <bobblick@ftml.net> wrote:

>
> On Tue, 18 May 2010 10:21:43 -0700, "William Chops Westfield" said:
>
>> Stacking is another option; I'm also surprised that the design  
>> doesn't
>> already parallel gates for increased drive; I thought that was pretty
>> standard for "driving" LEDs from 4000 series CMOS...
>
>
> Make a "cmos sandwich"!
>
> That's probably the easiest solution of all, since you don't need to
> replace the existing part, just put another(or two) on top. Especially
> easy if they are DIP, but not hard even if they are SOIC.
>
> Cheerful regards,
>
> Bob
>
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