20 Feb
2017
20 Feb
'17
8:51 a.m.
ok turns out - from what i am reading of the datasheets - that the bq24193 can cope with running from 3.3v, it looks like it doesn't mind: the limit of the I2C and other pins is 6V.
the bq27542 is a different matter (i thought it was 1.8v, it's not: it's 2.5v). it has its own 2.5v LDO on-board but the maximum input voltage is 2.5v for its I2C and HDQ (status / IRQ pin). sooo what i've done is, connect the 2.5v output (REG25) to the level-shifter, and the other side to VREFTTL.
i updated the schematics pdfs.
l.