--- crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68
On Wed, Mar 2, 2016 at 4:48 PM, Luke Kenneth Casson Leighton lkcl@lkcl.net wrote:
On Wed, Mar 2, 2016 at 4:25 PM, Jakub Kákona kaklik@mlab.cz wrote:
But a current design is still not fully clear to me.
ok i've created a diagram, it's basically identical to the current PCB3 schematic, except LTC4155 is replaced by a combination of bq24193 plus txs0104 plus 1.8v regulator, and STC3115 is replace by BQ34Z100.
http://hands.com/~lkcl/eoma/laptop_15in/pcb3_diagram.png
key differences from what you *might* be expecting this Charger PCB to have:
1) there is NO 5V rail. 2) there is NO 12V rail 3 ) there is NO 3.3v rail 4) the (appx) 4.2V "SYS" voltage from the Charger IC goes straight out *as-is* 5) Digital GPIO requires a REF voltage to be safe and meaningful. this *has* to be EXTERNALLY SUPPLIED. 6) many devices are now USB-OTG compliant (2-way power), so that is a power output (***AND POWER INPUT***)
from what you wrote, you *may* have considered that something like this would be useful:
1) 5V DC output 2) 12V DC output 3) 3.3v output 4) DC charging input
such a board is not useful for this project, because such a design is for a standard laptop. this isn't a standard laptop, it's a USB-OTG-powered "embedded" device.
l.