I have a tantalex capacitor that I am curious about. A M39003.
I read a few articles on failure modes of tantalum capacitors, but I have trouble understanding the data sheet in regards to surge current rating
https://www.mouser.com/datasheet/2/427/150d-1764082.pdfSo assuming you are feeding it from a regulated power supply (5V), and the capacitor I have is 18V rated at 150uF, is there a concern from a low source impedance charging the capacitor on start up?
The capacitor ESR measures 0.18 ohms at 1khz, 0.2 ohms at 120Hz. Assuming a perfect supply, the inrush to a bare capacitor should be ~27A. I don't see a surge rating on the capacitor. Its big also. But I did read some articles that claim that tantalum capacitors have a surge rating, but it seems mostly to be in regards to voltage.
How do you find out what is acceptable for this capacitor to take? I feel like a infrequent event is not going to heat up such a large capacitor very much.
"Derating is a means for designers of space systems to further reduce the probability of failures by limiting the level of stresses to capacitors during application. Typical derating requirements for solid tantalum capacitors limit the maximum applied voltage to 50% of the rated voltage (VR) and the inrush currents are bounded by additional resistors used in series with the capacitors. First, in the 1960s, the requirement for resistors was 3 Ω per each volt of operating voltage, but by the 1980s, due to improvements in the reliability of the parts and a strong need to increase the efficiency of power supply systems, this requirement was reduced to 1 Ω, and in the 1990s even to 0.1 Ω per volt [6, 15] or 1 Ω, whichever is greater."
https://escies.org/download/webDocumentFile?id=60981Do each of these capacitor series just have a empirical number associated with required resistance? Where does a tantalex capacitor stand in regards to these numbers? It seems that the answer is between 0.1-3 ohms per volt, or in this case with a 5V supply, 0.5 to 15 ohms. Thats quite a range.