Power and clock management in nRF52840 is designed to automatically ensure maximum power efficiency.

The core of the power and clock management system is the power management unit (PMU) illustrated in the following figure.

Figure 1. Power management unit

Page-1 Rectangle.4 MCU MCU Rectangle.40 Rectangle.46 Internal voltage regulators Internal voltage regulators Rectangle.50 Dynamic connector.173 Rectangle.260 External power sources External power sources Rectangle.261 External crystals External crystals Rectangle.263 Internal oscillators Internal oscillators Dynamic connector.264 Dynamic connector.265 Dynamic connector.266 Dynamic connector.273 Dynamic connector.284 Dynamic connector.287 Rectangle.267 PMU PMU Rectangle.270 CPU CPU Rectangle.276 Memory Memory Rectangle.278 Peripheral Peripheral Dynamic connector.289 Dynamic connector.290 Dynamic connector.292 Dynamic connector.294

The PMU automatically detects which power and clock resources are required by the different system components at any given time. The PMU will then automatically start/stop and choose operation modes in supply regulators and clock sources, to achieve the lowest power consumption possible.