Timeline for Aluminum Electrolytic Decoupling Capacitors
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 21, 2015 at 0:29 | vote | accept | CommunityBot | ||
| Nov 21, 2015 at 0:27 | comment | added | Wesley Lee | For computer circuits (processor and GPU) some very very low ESR polymer eletrolythics are used. They provide good density for such high current applications, and are often used together with ceramic ones. | |
| Nov 20, 2015 at 21:14 | comment | added | user57037 | In high volume production, cost is very important. If you are seeing electrolytic caps in high volume production boards, cost is the likely answer. You also need to understand that there is a difference between "bulk" capacitance that is added to boards to stabilize rails against low-frequency variations and bypass caps which are paced close to power pins to help reduce voltage fluctuations caused by high current spikes in digital switching circuitry. For the former, electrolytic is OK. For the latter, it is a bad choice. | |
| Nov 20, 2015 at 20:28 | comment | added | user92289 | In the context that I have read these references in they are in no way concerned with economy. They are describing aluminum electrolytic capacitors as an inherently bad choice due to their high impedances. But I do understand what you are saying. | |
| Nov 20, 2015 at 20:20 | comment | added | user57037 | You have to consider cost. For small capacitors, ceramic chip types are very affordable. So for 0.1uF caps placed at VCC pins of IC's, ceramic is the way to go. It would be foolish to use electrolytic in that application. But when you start getting to 22uF or 47uF (which would be more bulk decoupling), ceramics are expensive. So you need to go to tantalum or electrolytic. Tantalum has had some supply issues in the past, and there are ethical concerns about how tantalum is mined. So some people don't like to use it. | |
| Nov 20, 2015 at 20:19 | answer | added | Neil_UK | timeline score: 2 | |
| Nov 20, 2015 at 20:07 | review | First posts | |||
| Nov 20, 2015 at 20:34 | |||||
| Nov 20, 2015 at 20:02 | history | asked | user92289 | CC BY-SA 3.0 |