| ??? 03/24/05 06:16 Read: times |
#90321 - RC-circuits are bullshit!! Responding to: ???'s previous message |
Russell said:
They designed the chip, so I guess they'll be able to guide you better than any of us. Indeed, and they do not get tired to recommend the use of supervisory circuits over and over again with their flash micros!! Please have a look at the many application notes they have published treating this issue. I think it was Oleg who focused on this topic in a very nice post some months ago. Think about what this RC-circuit does, if the supply voltage has a short dip. Will there any reset be invoked? No! So, why using a RC-circuit, if this only provides a reset when very certain conditions are fullfilled, which are very unlikely be fullfilled again and again? RC-reset works, if supply voltage shows a turn-on time of only one millisecond. This you will find in datasheet. But what, if this condition isn't fullfilled? No reliable reset! If your application accepts this, ok use this RC-circuit. But if you sell a 1000 Euro device, which will run ill, only because you saved the costs of a supervisory chip, this will be the last sold device and you might look for another job... There are many errata sheets, from atmel, intel, philips and others, which very clearly state, that their flash micro is in danger to loose stored code (or lock-bits!!) due to an unproper reset during power-down or power-up. So, why using then a RC-circuit? Makes this any sense? Kai |
| Topic | Author | Date |
| What do you think could happen if... | 01/01/70 00:00 | |
| The 10k from RST to GND | 01/01/70 00:00 | |
| Random resets.. | 01/01/70 00:00 | |
| Dogma. | 01/01/70 00:00 | |
| Oh yea ? | 01/01/70 00:00 | |
| Hmm | 01/01/70 00:00 | |
| brown outs | 01/01/70 00:00 | |
| Obscure | 01/01/70 00:00 | |
| RC Reset circuits. | 01/01/70 00:00 | |
| Something more to it ... | 01/01/70 00:00 | |
| ad wars between Maxim and Microchip | 01/01/70 00:00 | |
| Cutting teeth... | 01/01/70 00:00 | |
| recommend brown out detectors | 01/01/70 00:00 | |
| Which depends on for what.. | 01/01/70 00:00 | |
| built-in reset | 01/01/70 00:00 | |
| Re: Built in brown out? | 01/01/70 00:00 | |
| Better than I did.... | 01/01/70 00:00 | |
| Thanks, Michael. | 01/01/70 00:00 | |
| Why | 01/01/70 00:00 | |
| Other stuff ? | 01/01/70 00:00 | |
| many reasons | 01/01/70 00:00 | |
| Thats not correct. | 01/01/70 00:00 | |
| speak with forked tongue | 01/01/70 00:00 | |
| I agree | 01/01/70 00:00 | |
| re: dogma | 01/01/70 00:00 | |
| ESD events and EMI | 01/01/70 00:00 | |
| Re: Random resets. | 01/01/70 00:00 | |
| Lets not reject the obvious! | 01/01/70 00:00 | |
| no R | 01/01/70 00:00 | |
| RC-circuits are bullshit!! | 01/01/70 00:00 | |
| RC-circuits are bullshit!! | 01/01/70 00:00 | |
| Reset Capacitor | 01/01/70 00:00 | |
| You missed the question! | 01/01/70 00:00 | |
| Why guessing? | 01/01/70 00:00 | |
| RE:Why Guessing | 01/01/70 00:00 | |
| Timing | 01/01/70 00:00 | |
| Update | 01/01/70 00:00 | |
| not necessarily the reset | 01/01/70 00:00 | |
| Other derivatives | 01/01/70 00:00 | |
| if no cap | 01/01/70 00:00 | |
| No Cap | 01/01/70 00:00 | |
| not just a cap, but the right cap | 01/01/70 00:00 | |
| Which cap? | 01/01/70 00:00 | |
| depends | 01/01/70 00:00 | |
| Yes Cap | 01/01/70 00:00 | |
| directly | 01/01/70 00:00 | |
| RE:Directly | 01/01/70 00:00 | |
| yes | 01/01/70 00:00 | |
| Absolutely ! | 01/01/70 00:00 | |
| Update - ESD Problem? | 01/01/70 00:00 | |
| some ways | 01/01/70 00:00 | |
| some ways - more detail please | 01/01/70 00:00 | |
| details | 01/01/70 00:00 | |
| Car induction coil | 01/01/70 00:00 | |
| ESD Problem | 01/01/70 00:00 | |
| Physical Separation | 01/01/70 00:00 | |
| Few Ideas | 01/01/70 00:00 | |
| Re: Few Ideas | 01/01/70 00:00 | |
| Check your external ground | 01/01/70 00:00 | |
| Ya. | 01/01/70 00:00 | |
| now that you are willing | 01/01/70 00:00 | |
| RE:Now that you are willing | 01/01/70 00:00 | |
| alot easier when you know what your look | 01/01/70 00:00 | |
| Not as bad as initially thought. | 01/01/70 00:00 | |
| ground loop | 01/01/70 00:00 | |
| RE: Ground Loop | 01/01/70 00:00 | |
| sound | 01/01/70 00:00 | |
| RE: Ground Loop | 01/01/70 00:00 | |
| It is a loop AND | 01/01/70 00:00 | |
| It's a loop and a flop | 01/01/70 00:00 | |
| no shield can help you there | 01/01/70 00:00 | |
| Kind of machine | 01/01/70 00:00 | |
| so your testbench setup should be OK | 01/01/70 00:00 | |
| Failures | 01/01/70 00:00 | |
| in that case | 01/01/70 00:00 | |
| Materials | 01/01/70 00:00 | |
| could still be ground | 01/01/70 00:00 | |
| Noise resistance | 01/01/70 00:00 | |
| you will not find that | 01/01/70 00:00 | |
| What can be found? | 01/01/70 00:00 | |
| tough these days | 01/01/70 00:00 | |
| Glue ? | 01/01/70 00:00 | |
| No Glue | 01/01/70 00:00 | |
| lesse some pictures. | 01/01/70 00:00 | |
| LOL | 01/01/70 00:00 | |
| Nope | 01/01/70 00:00 | |
| Let the fun begin! | 01/01/70 00:00 | |
| Confession | 01/01/70 00:00 | |
| Confession | 01/01/70 00:00 | |
| Ah. | 01/01/70 00:00 | |
| Not that bad | 01/01/70 00:00 | |
| HAr to see but | 01/01/70 00:00 | |
| Wiring & Filter | 01/01/70 00:00 | |
| Maybe a little better pictures here | 01/01/70 00:00 | |
| nice | 01/01/70 00:00 | |
| Oops - try again | 01/01/70 00:00 | |
| Uh Oh | 01/01/70 00:00 | |
| Yep | 01/01/70 00:00 | |
| Don't ground both ends of shield | 01/01/70 00:00 | |
| bonding | 01/01/70 00:00 | |
| RE: Bonding | 01/01/70 00:00 | |
| Useless.... | 01/01/70 00:00 | |
| Better Pix yet? | 01/01/70 00:00 | |
| Re: Better Pics Yet? | 01/01/70 00:00 | |
| DETAILS... | 01/01/70 00:00 | |
| Nothing hiding here! | 01/01/70 00:00 | |
| !!!!! | 01/01/70 00:00 | |
| I don't think so. | 01/01/70 00:00 | |
| !! | 01/01/70 00:00 | |
| Grounding. | 01/01/70 00:00 | |
| Grounding | 01/01/70 00:00 | |
| Prahlads points | 01/01/70 00:00 | |
| Clarification | 01/01/70 00:00 | |
| Clarification | 01/01/70 00:00 | |
| Update | 01/01/70 00:00 | |
| au contraire | 01/01/70 00:00 | |
| The answer may be on the horizon | 01/01/70 00:00 | |
| not the voltage, but the change | 01/01/70 00:00 | |
| Have a look see | 01/01/70 00:00 | |
| I do not know how good | 01/01/70 00:00 | |
| 7805 Starving | 01/01/70 00:00 | |
| it will go HOT | 01/01/70 00:00 | |
| Heatsink | 01/01/70 00:00 | |
or it's possible | 01/01/70 00:00 |