Switched regulator 5v 8A SMD (to replace XL4016) - Page 1
Forum section: electronics / projects

author: luiHS
author_rank: Frequent Contributor
timestamp: April 09, 2019, 12:03:51 pm
content: Hello.I have been using the XL4015 and XL4016 switched regulators for a long time. The first is SMD, but the second is THT.Somebody know any switching regulator integrated in a single chip, which can give 5v 8A?, I look for an alternative to the XL4016, but in SMD.Regards.

author: jonroger
author_rank: Regular Contributor
timestamp: April 11, 2019, 07:23:50 pm
content: Consider using this to select and design:https://webench.ti.com/power-designer/switching-regulator

author: luiHS
author_rank: Frequent Contributor
timestamp: April 12, 2019, 11:43:30 pm
content: Quote from: jonroger on April 11, 2019, 07:23:50 pmThank you, but Texas solutions are expensive and complex, they do not have a chip that does it all, such as the XL4016.

author: wraper
author_rank: Unknown
timestamp: April 13, 2019, 12:09:20 am
content: Frankly, it would be more efficient and cheaper with separate controller IC + 2 MOSFETs (or one dual in single package).

author: jonroger
author_rank: Regular Contributor
timestamp: April 13, 2019, 02:09:25 am
content: The XL4016 requires about the same number of external parts as TI solutions.

author: luiHS
author_rank: Frequent Contributor
timestamp: April 13, 2019, 10:52:17 am
content: I found an interesting chip in the Texas search engine, the LM25085. The difference is that this needs an external MOSFET, I will see what prices the Chinese offer me to see if the replacement is comparable in price.I have the inductor located in one of my Chinese suppliers, at 0.29 USD, something cheaper than I use for the XL4016, and it is also smaller because it is of a lower value. I might finally be interested in using the same circuit to replace XL4015 and XL4016, if I get a good price for the LM25085MY/NOPB and the Si7149DP MOSFET.I was surprised by the low values of the input and output capacitors that the LM25085 needs, only 22 and 47uF, while with the XL4016 it needs 470uF and 220uF, and the XL4015 needs 220uF and 330uF.In the application diagram of the LM25085, it states that the input capacitor of 22uF is ceramic size 1206, and the output capacitor of SMT tantalum. Interesting that they are not electrolytic, so I can mount them more easily in my pick and place machine, because of the small size.

author: wraper
author_rank: Unknown
timestamp: April 13, 2019, 11:47:17 am
content: Quote from: luiHS on April 13, 2019, 10:52:17 amElectrolytic capacitor at the output of buck converter is a thing of the past. If you take any modern computer hardware, you won't find them at the output of buck converter. I suggest finding controller IC which uses second MOSFET instead of the diode. Would produce way less heat.QuoteIf you are concerned about price, find Asian brand MOSFET. Such as Alpha & Omega Semiconductor, ubiq-semi and similar.

author: jonroger
author_rank: Regular Contributor
timestamp: April 13, 2019, 12:43:08 pm
content: See here for why electrolytic capacitors can still be relevant to buck converters:http://www.ti.com/lit/an/slyt639/slyt639.pdfDiode vs mosfet heat depends, but they are usually similar.