O.T charging current set resistor help

tony_g

Senior Member
i got my digikey order today with lots of great things to play with, amongst them a little single cell li-ion/li-po charger ic.

currently the only little single cell i have to eventually test it with handles a max 1c charge of 100mah, after looking through the datasheet i really cant seem to find any info on how to calculate the required resitor value for the R-iset pin for setting my required max charge rate of 100mah, only a calculation for how to monitor it from a uc.

maybe i have been looking at far too many datasheets lately and just fried the brain, can anyone help.

thanks,

tony


View attachment MC34673.pdf
 

premelec

Senior Member
P14 of the data sheet [RTFDS!] says Ichg = 4000 / (Rset + 96) - but test it on an ammeter before you try it on a live cell! This may not be the only way to find Rset...
 

tony_g

Senior Member
thanks, i was reading more on the operations description section and clearly went straight past that maybe as it was stuck in a small section below the graph,

incidentally RTFDS! little bit harsh considering all of us sometimes miss something small on a product datasheet, and more so for those familiar with short abbreviations particularly the F!.

but thankyou anyway premelec.


tony
 

premelec

Senior Member
Sorry I should have thrown in a smiley or two - I don't personally take RTFM as an imperative but as a humorous suggestion - I guess it's context sensitive... well WTP [What The PICAXE] - hope it works...
 

tony_g

Senior Member
ah its ok, ive just seen that used too many times on other forums when someone needs help but its always followed by bad attitude from who ever posted.

thats the only problem with the written or more so typed word, that it lacks the addition of tone and body language to help decipher its intent of humour or frustration :p


tony
 
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