| ??? 08/11/06 13:05 Read: times |
#122038 - MAX232-alike pin 2 capacitor |
I just read in a local conference about this - for me somewhat surprising - experience: when using the MAX232 and similar, in some of the datasheets and appnotes the capacitor from pin 2 is connected to VCC. I thought, it is not necessary, as from the high-frequency point of view, VCC and GND are shorted.
So I learned, that while the pump oscillator is running, this is true, but it is vital to make the connection to VCC for proper startup. He said, that certain derivative (he could not remember exactly, which) did not start properly, when loaded (PC connected), with the capacitor (100nF) from pin 2 grounded. He remembered it as they needed to remake the PCB for quite a big batch. Maybe this information saves somebody's sleepless nights... Jan Waclawek |
| Topic | Author | Date |
| MAX232-alike pin 2 capacitor | 01/01/70 00:00 | |
| elementary, my dear Watson | 01/01/70 00:00 | |
| not so quickly, Holmes | 01/01/70 00:00 | |
| Oi. | 01/01/70 00:00 | |
| I sure can | 01/01/70 00:00 | |
| cheating IS allowed | 01/01/70 00:00 | |
| Jan please edit to this | 01/01/70 00:00 | |
| talking about cheating | 01/01/70 00:00 | |
| Erik, you\'re going to regret having said that ... | 01/01/70 00:00 | |
| I have done it for "is it there" | 01/01/70 00:00 | |
| Jan, that\'s been in the datasheet since day 1 | 01/01/70 00:00 | |
| that was not max | 01/01/70 00:00 | |
| You really do need to read the materials | 01/01/70 00:00 | |
| OK, I will behave :-) | 01/01/70 00:00 | |
| Different charge pumping methodes | 01/01/70 00:00 | |
| misleading | 01/01/70 00:00 | |
| Sure? | 01/01/70 00:00 | |
| sure. | 01/01/70 00:00 | |
Was a typo | 01/01/70 00:00 |