On (19 Jan 95) [EMAIL PROTECTED] wrote to All... > Frode Tennebo <[EMAIL PROTECTED]> at 19 Jan 1995 14:56:03 >> "[EMAIL PROTECTED]" at Jan 19, 95 12:10:38 pm >>> [EMAIL PROTECTED]
>>> PS re 74, HC374 & HC574 they are functionally the same! BUT their D->Q >>> pinout is totally different.. next time look at the pinouts first;-) >> According to my Maplin catalogue they have identical pinouts. > Right! >> Unfortunately the catalogue doesn't say whether they have buffered >> outputs or not and doesn't give the output characteristics either. > Doesn't it give '_' on top of the Q-lines? on the 374? Why on earth should it say they're active-low when they are NOT? FYI:- from the 1993 TexasInstruments HC Data book... 74HC574 | 74HC374 1- /OC 20- Vcc | 1- /OC 20- Vcc 2- 1D 19- 1Q | 2- 1Q 19- 8Q 3- 2D 18- 2Q | 3- 1D 18- 8D 4- 3D 17- 3Q | 4- 2D 17- 7D 5- 4D 16- 4Q | 5- 2Q 16- 7Q 6- 5D 15- 5Q | 6- 3Q 15- 6Q 7- 6D 14- 6Q | 7- 3D 14- 6D 8- 7D 13- 7Q | 8- 4D 13- 5D 9- 8D 12- 8Q | 9- 4Q 12- 5Q 10- GND 11- CLK | 10- GND 11- CLK Both chips ARE logically and electrically the same, the only differences are the pinouts with the HC574 being more suitable to attachment to an inline 8-bit bus PCB layout that is all! If maplins claim they have the same pinouts then they are wrong! Johnathan. ... The truth is one thing that nobody will believe. -- |Fidonet: Johnathan Taylor 2:2501/307.9 |Internet: [EMAIL PROTECTED] | | Standard disclaimer: The views of this user are strictly his own.
