Timeline for Sprinkle switching circuits liberally with small capacitors?
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 20, 2016 at 2:51 | answer | added | Guill | timeline score: 1 | |
| May 18, 2016 at 13:36 | history | tweeted | twitter.com/StackElectronix/status/732927925738213376 | ||
| May 14, 2016 at 21:50 | comment | added | user105652 | For audio op-amps a power supply bypass of 33 ohms to the pin, with both a 10uF Tantalum capacitor and a .1uF in parallel are good for high-performance audio or DC amplifier applications. | |
| May 14, 2016 at 21:47 | comment | added | user76844 | Yes, in most cases it's not even a thumb rules, just a habit. Actually, not many people bother with the question "why". By the way, same happens even where calculation may be used, like in switching supplies. Then you ask the designer, why the capacitor is so big, can't he take a cheaper one, amd he says "no idea, i always use 100uF". We all hope that IC designers recommend decoupling because they know something we don't. But frankly, i lost my trust in them too. Their recommendations for hard components like FPGA are barely realistic, so it always looks they just escape responsibility. | |
| May 14, 2016 at 21:37 | comment | added | The Photon | Capacitors at the supply are not adequate because there is trace inductance and resistance between the supply and the load. | |
| May 14, 2016 at 21:33 | comment | added | Andrew Morton | The power supply cannot compensate for the induction of the current path between it and the component. The induction acts to slow down the recovery of the voltage to its required value. A capacitor immediately next to the component has less inductance in the path and so can reduce the change in voltage at a higher rate. (As far as I understand the operation.) | |
| May 14, 2016 at 21:18 | comment | added | feetwet | @AndrewMorton - Wow, that is very illuminating. It might be the whole answer. I see, "Put bypass caps everywhere if space and cost allow," "on every power input" (though why power supplies don't provide adequate capacitance isn't addressed), and "decoupling caps as specified by ICs." Is that all accurate and complete? | |
| May 14, 2016 at 21:08 | comment | added | Andrew Morton | Does What is a decoupling capacitor and how do I know if I need one? answer your question? | |
| May 14, 2016 at 20:59 | history | asked | feetwet | CC BY-SA 3.0 |