| ??? 12/19/05 14:22 Read: times |
#105527 - Reason why Responding to: ???'s previous message |
Steve said:
Presumably more electronics takes more power. Exactly! A quartz oscillator is designed to have a large fan-out and at the same time providing fast slew rates. For this, internal circuitry often uses very fast and strong gates, like 74ACMOS, for istance. This results in much higher current consumption compared to the rather "weak" internal Pierce oscillator of micro. This built-in oscillator is designed to optimally fullfill the needs of the micro. Here low current consumption and low supply ripple is demanded. Slew rate and fan-out are not in the focus, because the slew rate is just as fast as it's needed to make the internal gates to toggle, and fan-out capability is very weak, only one additional 74HCMOS gate is standardly allowed to be driven. Current consumption of quartz oscillator chip I worked with some time ago, was about 20mA at 10MHz, but can drastically be higher, as experience shows. Kai |
| Topic | Author | Date |
| Help identifying these crystals ? | 01/01/70 00:00 | |
| Could be a oscillator | 01/01/70 00:00 | |
| Post a picture | 01/01/70 00:00 | |
| Picture - hint | 01/01/70 00:00 | |
| If it is crystal...? | 01/01/70 00:00 | |
| picture here | 01/01/70 00:00 | |
| Yes. | 01/01/70 00:00 | |
| Look here | 01/01/70 00:00 | |
| Give me some! | 01/01/70 00:00 | |
| "Standard" Pinout? | 01/01/70 00:00 | |
| Follow up | 01/01/70 00:00 | |
| Post Script | 01/01/70 00:00 | |
| Yep. | 01/01/70 00:00 | |
| XTAL 1 | 01/01/70 00:00 | |
| XTAL2 | 01/01/70 00:00 | |
| Take care... | 01/01/70 00:00 | |
| Need to be cautious | 01/01/70 00:00 | |
| yes, but for the opposite reasons of us | 01/01/70 00:00 | |
| higher consumption | 01/01/70 00:00 | |
| bound to | 01/01/70 00:00 | |
| Reason why | 01/01/70 00:00 | |
consumption | 01/01/70 00:00 |