Do Chinese Power Supplies use Power Integrations chips? - Page 1
Forum section: electronics / beginners

author: opampsmoker
author_rank: Regular Contributor
timestamp: December 28, 2020, 05:44:10 pm
content: Hi,You would think the high level of integration of these chips would make them desirable for our imported Chinese SMPS's...but i dont think the Chinese use them?...do you know why not?

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 28, 2020, 05:46:22 pm
content: Do your own homework or hire a competent consultancy firm, treez.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 28, 2020, 05:47:04 pm
content: Because There are Chinese manufacturers of similar chips - Bright Power is one that comes to mindhttp://www.bpsemi.com/en/

author: chris_leyson
author_rank: Super Contributor
timestamp: December 28, 2020, 05:52:16 pm
content: They go off with a load pop and let the magic smoke out when you apply EFT, electrical fast transient voltages. 2kV was enough to kill Power Integrations flyback controllers.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 28, 2020, 05:54:10 pm
content: Here's an example of an isolated AC/DC PSU controller for 5V USB supplies, costs about 7 cents at LCSChttps://datasheet.lcsc.com/szlcsc/2010160533_Shenzhen-Fuman-Elec-FM3783A_C255562.pdfA comparable device from PI, Linkswitch 3 costs about 8x as much

author: opampsmoker
author_rank: Regular Contributor
timestamp: December 29, 2020, 01:51:52 pm
content: QuoteThanks, but as you know, EFT withstand depends on what transient protection, MOVs etc, that you add.QuoteThanks, but i think we all agree that the quality of features that you get with a power integrations chip is not found in Chinese offerings......(unless they have them but keep them for only internal Chinese useage).Take the Innoswitch, the HiperLCS, the HiperTFS and the HiperPFS.....and the fact that they all have heatsinking via the "quiet" gnd node, helping RFI immensely.Looking at the HiperPFS.....you get fet, soft recovery diode and controller on one thermally good package...no one else in the world does this....heatsink pad is to quiet node....brilliant power integrations.Look at innoswitch....sec to pri feedback with no opto coupler!...the first in the world...and its not burst mode either..its full error amplifier crossing over that mains isolation barrier !......and even an output sync fet driver ! The package is so noise immune that you can even put it right under the transformer, hence saving space...superb power integrations...why they are not used in the mass produced power supplies from China i dont know?QuoteIt would be interesting to see a list of SMPS design consultancies in the UK and EU. There may be some in EU....but in UK? There are individual contractors yes.In the UK we have eg stontronics who will get your SMPS done for you in China if you want...undercutting what any local consultancy would offer you.

author: dmills
author_rank: Super Contributor
timestamp: December 29, 2020, 03:15:43 pm
content: Yep, PI and friends are fine when you have something where you just need a jellybean small supply and do not want to actually design it (and this is often the case when working on a much bigger system), but if BOM cost matters or you want real performance there are other approaches.The PI stuff may in certain ways be clever, but usually you don't really need that, and good enough is good enough, especially when it is half the price or less.PI is for when I need to put something on the board and need the design finished today with a reasonable chance of it working, it is not for high volumes or anything I care about enough to actually put the effort in, but when it is something like a stupid little standby flyback or such, and I got better things to be doing, I am glad they exist (Sometimes, phoning it in is good enough).

author: Simon
author_rank: Unknown
timestamp: December 29, 2020, 03:23:01 pm
content: Not sure why you ask the question, who care? I mean think about it, the least you need to make a half decent SMPS is a comparator, a MOSFET and a voltage reference in terms of silicon, once you put those on the same die you have a controller. why would you use 3 separate devices that could be made more cheaply on one die?

author: Wimberleytech
author_rank: Super Contributor
timestamp: December 29, 2020, 04:21:35 pm
content: Here is a POWI chip in the Apple 18-W charger.Low volume?Low performance?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 29, 2020, 04:39:08 pm
content: Quote from: opampsmoker on December 29, 2020, 01:51:52 pmYes you do know - The Chinese chips are cheaper and "good enough" . Nothing more to it.

author: opampsmoker
author_rank: Regular Contributor
timestamp: December 29, 2020, 05:03:39 pm
content: Thanks Wimberleytech in your post #9...that looks like it could compete on price/size with anything on the market....and is an innoswitch i believe(?).I must admit i think its a bit of a miss that HiperTFS and HiperLCS doesnt come with an output synchronous rectifier dirver....even if they only outputted the sync rect drive signals for people to use themselves...such a feature would have made these superb all-rounders. As you know, those add-on sync rect drivers that sit on the secondary side and have no comms with the primary are all seriously dodgy under certain conditions. However, if vout is say 48V/60v and low current, then i guess HiperLCS and HiperTFS would be fine as wouldnt need sync rects.The one classic looks to be HiperPFS-4. This contains a soft recovery diode and fet and the controller in a thermally good package, with heatpad to the quiet gnd node. Considering the ubiquity of Boost PFC stages, i am amazed that the HiperPFS-4 hasnt knocked everything else out of the market. ( i must admit from a quick read of the datasheet i am not sure why the vout has to be 385V...but i may have mis-read)