Hi all,

I want to know the port current rating and power dissipation of the Z80PIO and the 8255A, but cannot find them on their datasheets. Can anyone please tell me what are these parameters called in datasheets??

 

8255A...page3-118http://www.jameco.com/Jameco/Products/ProdDS/52732.pdf

Ken

 

Thanks for the reply. So which one is the output current from the ports? is it the 2.5mA ?

 

I_DAR

Ken

 

It wouldn't be very much, the port current. Enough to drive (fan out) your buffers.

 

I believe Toshiba makes/made an 8255 capable of higher output current, maybe
15 or 20 ma if I remember right.

 

Hi again,

Thanks for the replies. Why is I_DAR a negative value please? and regarding the Z80PIO where can i find the power please?

Thanks in advance

 

Hi again,

Thanks for the replies. Why is I_DAR a negative value please? and regarding the Z80PIO where can i find the power please?

Thanks in advance

By nearly universal convention, IC pin currents are positive for current going INTO the pin. Many datasheets get sloppy and just give absolute values.

This convention, as far as I know, stems from the early days of circuit simulation so that consistent definitions were used for device models and interpreting sim results.