| ??? 01/18/05 11:30 Modified: 01/18/05 11:33 Read: times |
#85180 - 1k plus 1M Responding to: ???'s previous message |
Payam said:
There is a schematic in pjrc.com/tech/8051/board4/schematic.html in which a couple of 1M resistors are connected to the xtal. One resistor in parellel with the xtall and the other one placed between the xtall and the XTAL2 (pin 20 of MCU). Why? In order to reduce EMI? Then how exactly? It's not two 1M resistors, but one 1M and one 1k resistor. Normally this 1M resistor is already built-in on chip, so there should not be a need for this 1MOhm. Unfortunately, publisher does not tell what micro is used, so you cannot have a look at datasheet for further details. This 1k resistor normally is used to limit the quartz drive level. Normally, this resistor isn't needed either, with most derivatives. But again no way to have a look at datasheet. Payam, do only use those components arround oscillator which the manufacturer of micro recommends. For this have a look at actual datasheet. There's no further mistery. Good luck, Kai |
| Topic | Author | Date |
| 1M resistor in xtal oscillator | 01/01/70 00:00 | |
| discussed in detail | 01/01/70 00:00 | |
| Crystally confusificationifized | 01/01/70 00:00 | |
| Did you read this one? | 01/01/70 00:00 | |
1k plus 1M | 01/01/70 00:00 |