| ??? 12/26/07 18:53 Modified: 12/26/07 18:55 Read: times |
#148734 - H ??? Didn\'t they quit making that in the \'70s? Responding to: ???'s previous message |
are you sure you don't mean 'C'? The 'H' series had a lower input impedance than the standard TTL and LS, all of which require much more current than what his input circuitry can provide. Remember, with TTL, you're "looking" into an emitter at the input. That is a current source.
RE |
| Topic | Author | Date |
| 8051 Port Pin wont go low | 01/01/70 00:00 | |
| Try this | 01/01/70 00:00 | |
| here is the schematic | 01/01/70 00:00 | |
| RC-reset is wrong! | 01/01/70 00:00 | |
| That RST schematic is for AVR , which | 01/01/70 00:00 | |
| yes schematic shows wrong reset | 01/01/70 00:00 | |
| Low state current | 01/01/70 00:00 | |
| I tried this | 01/01/70 00:00 | |
| You should use CMOS | 01/01/70 00:00 | |
| here is the code | 01/01/70 00:00 | |
| signal source is inadequate, code is irrelevant | 01/01/70 00:00 | |
| The 7407 has the same problem ... | 01/01/70 00:00 | |
| would this work? | 01/01/70 00:00 | |
| why not 'H' why 'HC"? | 01/01/70 00:00 | |
| its what I have | 01/01/70 00:00 | |
| H ??? Didn\'t they quit making that in the \'70s? | 01/01/70 00:00 | |
| 74HC04 is working | 01/01/70 00:00 | |
Single transistor | 01/01/70 00:00 | |
| these superfluous facts in the datasheet | 01/01/70 00:00 |