21.5.1 Voltage Regulators

Two embedded voltage regulators are used to provide VDDCORE to the device:
  • The Main voltage regulator (MAINVREG)
  • The Low-Power voltage regulator (LPVREG) used when the device is in Standby Sleep mode

The Main Voltage Regulator has two modes:

  • Linear (LDO) mode: The default mode after reset.
  • Switching (BUCK) mode: The most power efficient mode when the CPU and peripherals are running (Active mode) and which requires an external inductor between VDDOUT and VDDCORE.
    Note: In Active mode, the voltage regulator can be selected on the fly between LDO (low-dropout) type regulator and Buck converter using the Supply Controller (SUPC)

One embedded voltage regulator (VREGPLL) is used to provide VDDPLL to the device.