Latest hotness in buck/boost converter chips? - Page 1
Forum section: electronics / projects

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 12, 2018, 04:19:59 am
content: I have a few of those ebay buck and boost converter modules that I use for basic stuff and I was looking at getting some of the LM2596 etc chips from Digikey to make my own buck converters, but the price of those things is somewhat ridiculous IMO...I'm just wondering what is the latest 'go-to' buck and boost converter chips for general use? There's so many out there it's a bit hard to narrow down.I just need something for the same use cases as the ebay modules would be used for.

author: Tomorokoshi
author_rank: Super Contributor
timestamp: August 12, 2018, 04:46:21 am
content: Yes, it seems like there is an excess of options. Let's narrow in on some of the requirements:Voltage input range?Voltage output range?Current output range?Frequency preferences?Internal or external switch?Topology?Peripheral functions such as current limiting, soft start, etc.?

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 12, 2018, 07:00:01 am
content: They will be used for just the usual use cases for battery power and converting say 12v to 5v, or 24v to 12v or 5v, etc etc, for whatever projects I need them for.Basically about what an adjustable LM2596 and the like can do.Voltage input range? Up to 30-ish volts or so.Voltage output range? Up to 12-ish volts or so.Current output range? One or two amps.Frequency preferences? No special requirement.Internal or external switch? Internal switching for simplicity.Topology? No special requirement.Peripheral functions such as current limiting, soft start, etc.? No special requirement except maybe thermal shutdown etc.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 12, 2018, 02:42:11 pm
content: If you don't have any particular requirements, or high efficiency, just keep using SimpleSwitchers. They're cheap as sand.I'm fond of at least a few in the TPS54xxx range, the "EcoBoost" ones seem alright, among others. Beware there are still voltage and hysteretic-mode controllers being made to this day; check the datasheet to make sure they're current mode.There are some quite tiny ones (I forget if TPS or LM something), that'll do 3A in a SOT-23-6.Tim

author: chris_leyson
author_rank: Super Contributor
timestamp: August 12, 2018, 03:02:26 pm
content: The LMZM23600 will do a 0.5A buck converter, tiny 3.0 x 3.8mm package and you just need input and output capacitors. LMZM23601 will do 1A.

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 13, 2018, 01:37:34 am
content: Cool thanks, I'll check them out.I have no specific requirements beyond 'I need 5v here for this module here and I have 12V input voltage to my device' kind of thing. Like running a raspi from the PSU in my 3d printer, or a 5V Digital TV tuner from the 12V input to my portable colour CRT.

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: August 17, 2018, 10:04:32 am
content: I have to support Tims suggestions for TPS54xxx. I have been using the TPS54283 quite excessively in the last time. Very nice datasheed with detailed descriptions on how to calculate all sorts of stuff including not only the "how" but also the "why", which I liked very much. TSSOP14 with Power Pad is also quite manageable with a cheap hot air station. It features dual output with up to 2A, integrated FET, input should go up to... i guess around 30V-ish? (Used them with 24V) and can output down to .8V. Overcurrent protection is also on board. Switching frequency is 300kHz, if you prefer 600 chose the TPS54286.For boost converters however I am also still looking for a nice solution.

author: Rolo
author_rank: Regular Contributor
timestamp: August 17, 2018, 04:18:29 pm
content: For boost converters you can take a look at the LM2733.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 17, 2018, 05:57:02 pm
content: Wow... look at the headline schematic:http://www.ti.com/lit/ds/symlink/lm2733.pdfNot sure how they screwed that up...Specs and internal diagram look alright though.Tim

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: August 17, 2018, 06:39:50 pm
content: Quote from: Rolo on August 17, 2018, 04:18:29 pmThat one looks quite nice amd easy to implement. Lastly I am fiddling around a lot with VFDs which would be happy to have around 48 Volts, so that one isn't suitable. I will try the LM5002 instead.Quote from: T3sl4co1l on August 17, 2018, 05:57:02 pmWOW, that is fascinating o.o

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 20, 2018, 06:10:30 am
content: Awesome info, thanks! I have a good amount to go through now.Keep the suggestions coming!