| ??? 02/23/07 14:38 Read: times |
#133546 - faster logic gate? |
I have a design that would benefit more from a 4-input "AND" gate, than it would from a 3-input one.
My 80C51-BH clock is set at 18 Mhz. According to my local store, they carry 4-input "AND" gates as 74xx and 4xxx IC's. One website states that the 4xxx IC's can only be efficient to 1Mhz. Since the byte execution speed is about 1.5Mhz (18.432Mhz crystal / 12), I am not confident in using 4xxx IC's here. I hear that the 74xx IC's are very old, but it seems that I might have to resort to them. I don't want to use 74LS, because I made a design a while back (several months ago) with an AT89C2051, and the 74LS chips were overheating. I have a 4-input NAND in a 74HC series, but I wonder why they didn't make an AND in 74HC's as well. Here is a link to the store catalog: http://sayal.com/ActionInd...d+Circuits So to satify speed (very important), and to reduce the chances of failure, should I use 74xx series, or 4xxx series? for a 4-input AND gate? and why? |
| Topic | Author | Date |
| faster logic gate? | 01/01/70 00:00 | |
| yeahwhat you need is | 01/01/70 00:00 | |
| buying or making junk | 01/01/70 00:00 | |
| careful now ... that's not quite the case | 01/01/70 00:00 | |
| read before you write | 01/01/70 00:00 | |
OK, but it's still not true ... | 01/01/70 00:00 | |
| Try a datasheet | 01/01/70 00:00 |