Tom_Tom
(Tom Tom)
25
I’d recommend starting from the schematic of the BLF Q8 driver.
This is the classic FET+1, perfected by DEL, which is at the core of many subsequent drivers from other designers.
Note: R1 and R2, the old voltage divider, are not populated, current firmware uses a different method to measure cell voltage, and this, along with other firmare changes, reduced power consumption dramatically and freed up another pin (for e.g. driving a second bank of 7135s).
However if you want to experiment with e.g. BLF A6 or X6 drivers, and their simpler firmware, you would need to put them back.
DEL was generous enough to publish it, instead of only showing a PCB layout, and leaving it to the inquisitive to puzzle it out by reverse-engineering.
Here it is:
Open the image in a new tab and you’ll get the full size version from dropbox.