Feedback Input needs 250k Ohm equivalant to correctly bias diff pair of LT3652 feedback (Vfb) amplifier.
When the current in both legs of diff pair are matching then the network is at threshold voltage.
The 100k is a thermister (B=4250, i.e. 13.278V:50.7k@40C, 13.630V:100k@25C, and 14.068V:357k@0C) placed on SLA type battery to match charge voltage with temperature.
The more I look at LT3652 datasheet, which shows a 22k B=3380 thermister for temperature compensation, the fisher it looks. So I am trying to do compensation to this standby data: http://www.powerstream.com/SLA.htm
Circuit board(s) I am working on with this:
http://epccs.org/indexes/Board/CC03/
