Two 7490 to 74390

[kurt_issac]

Hello, can anyone guide me or help me on, how to substitute a 74390 Dual BCD Counter by using two piece of 7490 BCD Counter? Thanx!

 

[mvs sarma]

hi
do you really need to substitute-- why not, if possible original 74390 or 74ls390

if need to do.

make a small adopter board with berg pins at the botom to suite t4ls390 pin ot and put 2 nos 7490 on topnear to the pins and try hard wire.. -- laborious job--

sarma

 

[MNA]

connect Output Qd of first to input of second.....and do the other labour as pointed out by sarma