npm1300

[27] BUCK: Programming BUCK voltage increases current consumption

This anomaly applies to Engineering C, build codes QEAA-BA0, CAAA-BA0, QEAA-BC0.

Symptoms

Quiescent current of BUCK is higher than expected.

Conditions

Host software sets BUCK voltage for the first time after a power-up event, and the value is the same as the voltage already set by VSET resistor. This is done by setting BUCKnSWCTRLSEL to SWCTRL while BUCKnNORMVOUT and BUCKnVOUTSTATUS are equal.

Consequences

BUCK quiescent current increases by 1 mA.

Workaround

Host software must initially ensure BUCKnNORMVOUT and BUCKnVOUTSTATUS are not equal when BUCKnSWCTRLSEL is set. Host software can set BUCKnNORMVOUT equal to BUCKnVOUTSTATUS once an alternate BUCKnNORMVOUT has been set.