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27. PAC - Peripheral Access Controller
19.5.9 Analog Connections
Not applicable.
19.6 Functional Description
19.6.1 Voltage Regulator System Operation
19.6.1.1 Enabling, Disabling, and Resetting
The LDO main voltage regulator is enabled after a power-reset. The main voltage regulator output supply
level is automatically defined by the sleep mode selected in the Power Manager module.
19.6.1.2 Initialization
After a power-reset, the LDO voltage regulator supplying VDDCORE is enabled.
19.6.1.3 Selecting a Voltage Regulator
In Active mode, the type of the main voltage regulator supplying VDDCORE can be switched on the fly.
The two alternatives are a LDO regulator and a Buck converter.
The main voltage regulator switching sequences are as follows:
The user changes the value of the Voltage Regulator Selection bit in the Voltage Regulator System
Control register (VREG.SEL)
The start of the switching sequence is indicated by clearing the Voltage Regulator Ready bit in the
STATUS register (STATUS.VREGRDY=0)
Once the switching sequence is completed, STATUS.VREGRDY will read '1'
The Voltage Regulator Ready (VREGRDY) interrupt can also be used to detect a zero-to-one transition of
the STATUS.VREGRDY bit.
19.6.1.4 Voltage Scaling Control
The VDDCORE supply will change under certain circumstances:
When a Sleep mode (Standby, Hibernate, Backup) is entered or exited
When a sleepwalking task is requested in Standby Sleep mode
To prevent high peak current on the main power supply and to have a smooth transition of VDDCORE,
the Voltage Scaling Period field in VREG (VREG.VSPER) can be controlled: VDDCORE is changed by a
typical 5 mV of the selected voltage scaling period (2
VSPER
) * T until the target voltage is reached.
The smooth transition of VDDCORE is enabled/disabled by setting/clearing the Voltage Scaling Enable
bit in VREG (VREG.VSEN).
The following waveform shows an example of exiting the Standby Sleep mode.
SAM D5x/E5x Family Data Sheet
SUPC – Supply Controller
© 2019 Microchip Technology Inc.
Datasheet
DS60001507E-page 238