| ??? 06/22/09 12:26 Modified: 06/22/09 12:31 Read: times |
#166342 - MAX1232 + 4k7 pull-up Responding to: ???'s previous message |
Aleksandar said:
Does anyone have experience with ED2 regarding brown-outs, etc? Should I implement a reset IC or is internal circuit sufficient? I would use a MAX1232 in combination with 4k7 pull-up at its reset pin. I would also spend an additional 10k pull-up at PSEN pin of micro. The internal weak active pull-up presents a rather high impedance to noise and glitches, which is the reason I use 10k pull-ups at most of the port lines. A good 10µF cap (X5S, 0805, e.g.) across the Vcc line near micro and MAX1232 and the use of a solid ground plane is a must! Kai |
| Topic | Author | Date |
| AT89C51ED2 changing speed on its own | 01/01/70 00:00 | |
| apply proper reset | 01/01/70 00:00 | |
| apply proper reset | 01/01/70 00:00 | |
| then that's R0 not R1 | 01/01/70 00:00 | |
| MAX1232 + 4k7 pull-up | 01/01/70 00:00 | |
| I beliebe this chip has a built-in watchdog and thus ... | 01/01/70 00:00 | |
| I don't like those on-chip watchdogs and Vcc monitors | 01/01/70 00:00 | |
| Should be always on | 01/01/70 00:00 | |
| external vs internal | 01/01/70 00:00 | |
| .. | 01/01/70 00:00 | |
| Ground plane? | 01/01/70 00:00 | |
| no ground plane | 01/01/70 00:00 | |
| choose a "magic" frequency crystal ... | 01/01/70 00:00 | |
20MHz and 57600 | 01/01/70 00:00 |