teardown of an ultra compact high efficiency switched-mode power supply - Page 1
Forum section: electronics / general

author: jonovid
author_rank: Super Contributor
timestamp: December 16, 2020, 09:40:48 pm
content: compare two switched power supply's from laptop pc's with thesamewattage.one design is 10 or 15 years old, and the other is one of them next generation 2019 -2020 ultra compact high efficiency switched-mode power supply with an airtight case. that are sold with laptop pc'snext generation switched power supply's come in an airtight case half the size of older designs.what has changed in switched mode power design.

author: thm_w
author_rank: Super Contributor
timestamp: December 16, 2020, 10:18:56 pm
content: There are some cheap GaN units available:https://www.aliexpress.com/item/4001026960817.htmlI don't know if current laptops are using that yet.

author: jonovid
author_rank: Super Contributor
timestamp: December 17, 2020, 06:52:28 am
content: Quote from: thm_w on December 16, 2020, 10:18:56 pmpurchased a HP laptop with a ultra compact 45watt 19vlot 2.5 amp battery charger that ishalf the sizeof older laptop charger designs.the case is 90mm L (25mm is lost with a IEC C5 recessed 3 pin socket in the end) 25mm H 25mm Wthis unit has no ventilation slots. in an airtight case. it works fine,but I do wonder about how its designed.to stay cool . as my 3 amp bench power supply needs lots of ventiltion. can Dave do a teardown to unlock its secret?

author: CJay
author_rank: Super Contributor
timestamp: December 17, 2020, 12:09:28 pm
content: Quote from: jonovid on December 17, 2020, 06:52:28 amAll theones I've got here are 25x35x90mm, be interesting to see if the new stock I'm meanto to be getting early Jan come with smaller ones.I've got a couple of the 45W adapters which are dead enough (frayed or damaged cables which get failed by our H&S electrical safety checks) to be candidates for a teardown if he's interested.

author: Yansi
author_rank: Super Contributor
timestamp: December 17, 2020, 12:29:07 pm
content: Quote from: thm_w on December 16, 2020, 10:18:56 pmSeriously doubt there is any GaN in that thing. Pic or didn't happen!

author: Weston
author_rank: Regular Contributor
timestamp: December 17, 2020, 07:41:14 pm
content: Back when Anker came out with a GaN based USB charger I bought one and took it apart, I was actually pretty underwhelming. It used a highly integrated power IC that has all the power FETs, control circuity, and isolators. I suspect that most modern chargers are something similar.The one I took apart used a chip from Power Integrations, the primary side switch is GaN and it runs as a quasi-resonant flyback converterhttps://ac-dc.power.com/products/innoswitch-family/. I think some might also use an active clamped flyback design, that topology is popular now.Given the high level of integration they are pretty simple inside and I suspect that the GaN version of the power IC only costs a bit more than the Si version.

author: sandalcandal
author_rank: Unknown
timestamp: December 18, 2020, 03:34:39 am
content: I recently saw a webinar from a reverse engineering firm that did a brief segment on GaN-on-Si AC adapters.https://techinsights.wistia.com/medias/7ma357gv90@16:50 to 21:20 Alsohttps://www.techinsights.com/blog/navitas-found-inside-ravpower-rp-pc104-w-gallium-nitride-45-w-usb-c-power-delivery-chargerandhttps://www.eetimes.com/ac-adapters-gan-sic-or-si/(from the same author) They looked at a few including RAV Power, Made in Mind Mu One and mentioned Anker and FINsix. The implementations appear to be just based on reference designs of GaN ICs from Navitas and Popwer Integrations (which @Weston has also mentioned).

author: jonovid
author_rank: Super Contributor
timestamp: December 19, 2020, 10:56:42 pm
content: Quote from: sandalcandal on December 18, 2020, 03:34:39 amfinally found a clue to what semiconductor technology is been used here!it is gallium nitride.would a side by side comparison of the two types of technology be of any interestIMO the implications are huge , less heat , less weight more compact electronics.particularly in EV's or anything portable & high power.

author: sandalcandal
author_rank: Unknown
timestamp: December 20, 2020, 06:05:41 am
content: Quote from: jonovid on December 19, 2020, 10:56:42 pmGaN is starting to see use in some EV applicationsTendency seems more towards SiC rather than GaN for EV applications however due to limited "high voltage" (>600V) performance of GaN. The newer >800V EVs seem to be thanks to maturation of SiC technology.