A question about nrF52832's DC/DC and LDO

Hi,

In nRF52832_OPS_v0.6.3.pdf chapter 16 Power-Power management. It describle as follow: Automatic switching between LDO and DC/DC regulator based on load to maximize efficiency Is it mean that if I set DCDCEN=1, LDO may also be used? For my understand , if use DC/DC, LDO will not be functional. Would you please to explain the work mode of DC/DC and LDO in 52832?

  • If you set DCDCEN = 1, LDO will be used when the current is low. The DC/DC converter needs some current to be operational, therefore it is not efficient to keep it on when the CPU is sleeping and the radio is off. The system will use the DC/DC only when it is beneficial.

  • Thanks for your answer. If DCDCEN=0, system only use LDO,is it right?

    You mention "it is not efficient to keep it on when the CPU is sleeping and the radio is off", I found in Errata "DCDC does not automatically switch off in System ON IDLE",does it mean DCDC shoud automatically switch off when CPU is sleeping and radio is off. I have another quesiton, I want to test TX/RX peak current compared with LDO and DCDC, how to achieve it? In ble_app_pwr_profiling example of nRF5_SDK_11.0.0-2.alpha_bc3f6a0, I don't find any setting of DCDCEN, does it mean it only use LDO? Looking forward for your answer.

  • If DCDCEN = 0, system will only use LDO (the hardware for DC/DC may not be available). The DC/DC should automatically turn off when CPU is sleeping and radio is off. The errata "DCDC does not automatically switch off in System ON IDLE" is only present on engineering sample A and B, it is fixed on the newest versions of the chip. See this tutorial for how to workaround this issue. You enable DCDC with

    sd_power_dcdc_mode_set(NRF_POWER_DCDC_ENABLE);
    
  • You're welcome :) If you liked the answer please mark it as correct (check mark to the left below the arrows).

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