Under Battery Switch Operation on LP3972 data sheet page 16/62, It is stated that the battery switch may be disabled when only a main battery is used by setting the “no back up battery bit” in the control register 8h’0B bit 7 NBUB.
Since…
Other Parts Discussed in Thread: LP3972 On LP3972 application note (literature Number: SNVA235):
The two I2C lines are pulled-up to 3.3V in reference design board.
On LP3972 data sheet (literature Number: SNVS468J):
It is stated in page 4/62 that the two…