IC Vendor Selection Advice

[eas]

For a learning project, I'm going to build some circuits to make use of scavenged 18650 LiIon cells. One of the circuits I need is a charger for 3-4 cells in series. I'd like to find an IC that does most of the heavy lifting for me.

I'm prepared to do a lot of research digging through specs on manufacturer sites to find good candidates, but, I'd like to avoid doing a lot of work that isn't likely to go anywhere.

In particular, I get the sense that it is hard to get ahold of components from some manufacturers in hobbyist quantities at reasonable prices. Is this something that is worth worrying about? 

The other thing is that I'm willing to work with surface mount devices, provided the have edge connectors. Are some manufacturers more likely to have hobbyist friendly packaging options?

For both of the above questions which IC manufacturers are likely to lead to disappointment? Which are likely to bring me joy?

The list I'm starting with: Linear Devices, Microchip, TI, Atmel, STMicro, Cypress, Maxim.

If people have specific ICs, or product lines to recommend, I'd appreciate that too, but at this point I'd like to cast a reasonably wide net and then prioritize from there.

Thanks in advance for your advice!

[Whales]

Have you had a look at what element14, mouser, digikey etc currently have in their range?  It's one way of discovering what silicon is available to do your task.

eg http://au.element14.com/jsp/search/browse.jsp?N=202737+110657321+110201791+110657732+110155235+110190773+110657531+110191833+110133830+110289207+110657491+110657240+110074534+110098640&No=0&getResults=true&appliedparametrics=true&locale=en_AU&divisionLocale=en_AU&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=202737&mm=1002689||,1001113||,&filtersHidden=false&appliedHidden=false&autoApply=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN%3D202737%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_AU%26divisionLocale%3Den_AU%26catalogId%3D%26skipManufacturer%3Dfalse%26skipParametricAttributeId%3D%26prevNValues%3D202737

[janekm]

TI have a very generous sample policy. They also have plenty of charger / power management chips. For 18650 it is a good idea to add protection and cell balancing features to your charger, e.g.: http://www.ti.com/ww/en/analog/bq77910_integrated_battery_protection_solution/index.shtml

[Whales]

For 18650 it is a good idea to add protection and cell balancing features to your charger,

Charging series lithium chemistries in general requires some sort of balancing, IIRC.  I don't think you can (safely) avoid this.

[eas]

Have you had a look at what element14, mouser, digikey etc currently have in their range?  It's one way of discovering what silicon is available to do your task.

eg http://au.element14.com/jsp/search/browse.jsp?N=202737+110657321+110201791+110657732+110155235+110190773+110657531+110191833+110133830+110289207+110657491+110657240+110074534+110098640&No=0&getResults=true&appliedparametrics=true&locale=en_AU&divisionLocale=en_AU&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=202737&mm=1002689||,1001113||,&filtersHidden=false&appliedHidden=false&autoApply=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN%3D202737%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_AU%26divisionLocale%3Den_AU%26catalogId%3D%26skipManufacturer%3Dfalse%26skipParametricAttributeId%3D%26prevNValues%3D202737

You are probably right, I should be starting with the retailers and working back. I find it easier to understand a given ICs place seeing it the context of the manufactures product line, but ultimately, the limiting factor is price and availability, so I should be doing the first cut that way.

TI have a very generous sample policy. They also have plenty of charger / power management chips. For 18650 it is a good idea to add protection and cell balancing features to your charger, e.g.: http://www.ti.com/ww/en/analog/bq77910_integrated_battery_protection_solution/index.shtml

Charging series lithium chemistries in general requires some sort of balancing, IIRC.  I don't think you can (safely) avoid this.

Thanks, I will definitely be adding separate protection and balancing circuitry, but in my initial research, I found lots of sources for ready-made PCBs with various protection and balancing ICs, while, at the same time, finding very few options for 3-4S charging circuits, so thats where I'm focusing my efforts right now.

[David Hess]

I usually include Mouser, Digi-Key, and Newark early in my search to evaluate pricing and availability.