This anomaly applies to IC Rev. Engineering A, build codes SICA-BAA.
Symptoms
Leaving the regulators in LDO mode causes higher current consumption.
Conditions
Startup from reset.
Consequences
- The device current consumption will be higher. Exactly how much higher depends on the difference in efficiency in DC/DC and LDO regulators at a given supply level and the current draw of the device.
- The device is qualified using DC/DC converters. Qualifications and certificates created without DC/DC converters will hence be void.
Workaround
Application software needs to set the regulators into DC/DC mode before starting up the modem. Set registers at startup as described below. For secure mode:
*((volatile uint32_t *)0x50004A38) = 1;
NRF_REGULATORS_S->DCDCEN = REGULATORS_DCDCEN_DCDCEN_Enabled << REGULATORS_DCDCEN_DCDCEN_Pos;
For non-secure mode:
*((volatile uint32_t *)0x40004A38) = 1;
NRF_REGULATORS_NS->DCDCEN = REGULATORS_DCDCEN_DCDCEN_Enabled << REGULATORS_DCDCEN_DCDCEN_Pos;
Note: Workaround included as of MDK 8.21.0 and later releases.