| ??? 02/02/05 15:06 Read: times |
#86384 - Ripple Responding to: ???'s previous message |
Payam said:
In original MAX232 datasheet the capacitors are all 1uF. Why on earth almost every circuit I see uses 10uF capacitors? Due to the switch mode operation relevant ripple currents are flowing across the capacitors. High ripple currents result in decreased service life time. One consequence is a certain loss of capacitance over the months and years. Relevant temperature changes can also lead to a decrease of capacitance. So, a certain 'overhead' in capacitance would compensate for these losses. Another reason to use 10µ Tantals instead of 1µF ones is, that due to much lower equivalent series resistance (0.2 Ohm instead of 0.6 Ohm) the rippe suppression is much better. Kai |
| Topic | Author | Date |
| MAX232 Capacitors | 01/01/70 00:00 | |
| 1uF. | 01/01/70 00:00 | |
| for backward compatibility? | 01/01/70 00:00 | |
| 22uF cap. | 01/01/70 00:00 | |
| ST232 and MAX202 | 01/01/70 00:00 | |
Ripple | 01/01/70 00:00 |