| ??? 02/02/12 15:07 Read: 198 times |
#185781 - Power-On Glitch Responding to: ???'s previous message |
Hi,
Neil Kurzman said that , “I can assume you have an R/C reset on the 8052?” Thanks Neil… I’m already using it. It can’t solve this situation… Because proses ordinary is; 1-R/C Reset 2-8051 Start up ( It’s writing ports to logic-1) 3-My program… Richard Erlacher said that : “Low-side high-current drivers were driven with a positive output only to provide low-going drive to relays, LED cathodes, etc. Current was most commonly limited by resistors at the high-side, and the driver sank the current. As target devices became less power-hungry, the MCU's themselves became capable of driving some of them, hence, relatively high-current-sink low-current-source drivers at the MCU pins.” Thans Richard. I know them. 8051 I/O maximum output current is 15-20mA (approximitly) . Look at first schema in the below link http://www.8052.com/forum/read/178883 I won’t calculate at length. But, I/O pin output current through to Base pin is approximitly 1,9mA. However, 8051 can supprot 15-20mA. (approx. 10 times more) Due to that reason, current don’t have to flow outside to I/O pin. BTW, yes at first time low-active design was significat. ULN2003 etc. chips are used. But, some problems are noticed. Now, Hi-Active usage has started lately. UDN2981 etc.. David Prentice said that : “The solution is simple. An external pull-up or pull-down resistor… If you designed active-low, you use a pull-up. Active-high needs a pull-down.” Thanks David… I’ve already tried diffrent resistors between 5k and 10Ω. Anything hasn’t changed at the high value resistors. Output is not at the 10Ω. Thanks, Kai Klaas…. Very much… I think, I should use PIC series microcontroller for this kind of circuits…. |
| Topic | Author | Date |
| Power-On Port Status Problem | Adam Blue | 01/30/12 08:42 |
| Wrong idea | Per Westermark | 01/30/12 08:48 |
| you will not | Erik Malund | 01/30/12 08:49 |
| you are not the only one | Erik Malund | 01/30/12 09:18 |
| ATMEL be ashamed | Adam Blue | 01/30/12 15:05 |
| No, YOU should be ashamed... | Kai Klaas | 01/30/12 16:15 |
Nonsense!  | Andy Neil | 01/30/12 16:46 |
| PIC Does so | Neil Kurzman | 01/30/12 23:08 |
| Oh really?? | Michael Karas | 01/31/12 07:46 |
| "Glitch" in the sense of kind of "setback in a plane"? | Kai Klaas | 01/31/12 10:19 |
| Try These Ideas | Michael Karas | 01/30/12 17:21 |
| "Glitch" | Adam Blue | 02/01/12 13:12 |
| what is not “ATMEL true”. | Erik Malund | 02/01/12 13:37 |
| I think you are making excuses | Erik Malund | 02/01/12 13:41 |
| Oh, boohoo! | Rob Klein | 02/01/12 14:04 |
| What a bunch of fatty sausage... | Michael Karas | 02/01/12 14:59 |
| "very easy problem" | Andy Neil | 02/01/12 15:02 |
| Power-On Glitch | Adam Blue | 02/01/12 15:40 |
| Nonsense - again | Andy Neil | 02/01/12 16:28 |
| Please explain what the "power-on glitch" is ... | Richard Erlacher | 02/01/12 19:26 |
| Into The Frying Pan | Michael Karas | 02/01/12 20:52 |
| Power-on problem... | Kai Klaas | 02/02/12 05:55 |
| You are still blaming the tools | Per Westermark | 02/03/12 05:55 |
| Design the hardware first. | David Prentice | 02/02/12 07:21 |
| do not Design the hardware first. | Erik Malund | 02/02/12 07:30 |
| Power-On Glitch | Adam Blue | 02/02/12 15:07 |
| that you had the worst possible reset circuit | Erik Malund | 02/02/12 15:59 |
| RC-reset... | Kai Klaas | 02/02/12 17:20 |
| Sorry, double post, don't know why... | Kai Klaas | 02/02/12 17:21 |
| No, you're not the only one | Richard Erlacher | 02/02/12 21:12 |
| Would I Hire? | Michael Karas | 02/02/12 22:44 |
| incidentially | Erik Malund | 02/03/12 07:09 |
| Power On satus Problem | Satish S Munot | 02/29/12 10:16 |
echo, echo, echo | Erik Malund | 02/29/12 10:30 |