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SAM4CM Series [DATASHEET]
Atmel-11203C-ATARM-SAM4CM32-SAM4CM16-SAM4CM8-Datasheet_06-Oct-14
5.1.1
Core Voltage Regulator
The SAM4CM series embeds a core voltage regulator that is managed by the Supply Controller.
It features two operating modes:
In Normal mode, the quiescent current of the voltage regulator is less than 500 μA when sourcing maximum
load current, i.e. 120 mA. Internal adaptive biasing adjusts the regulator quiescent current depending on the
required load current. In Wait Mode, quiescent current is only 5 μA.
In Backup mode, the voltage regulator consumes less than 100 nA while its output (VDDOUT) is driven
internally to GND.
The default output voltage is 1.20V and the start-up time to reach Normal mode is less than 500 μs.
For further information, refer to Core Voltage Regulator characteristics in the section “Electrical Characteristics”.
5.1.2
LCD Voltage Regulator
The SAM4CM embeds an adjustable LCD voltage regulator that is managed by the Supply Controller.
This internal regulator is designed to supply the Segment LCD outputs. The LCD regulator output voltage is
software selectable with 16 levels to adjust the display contrast.
If not used, its output (VDDLCD) can be bypassed (Hi-z mode) and an external power supply can be provided onto
the VDDLCD pin. In this case, VDDIO still needs to be supplied.
The LCD voltage regulator can be used in all power modes (Backup, Wait, Sleep and Active).
For further information, refer to LCD Voltage Regulator characteristics in the section “Electrical Characteristics”.
5.1.3
Automatic Power Switch
The SAM4CM features an automatic power switch between VDDBU and VDDIO. When VDDIO is present, the
backup zone power supply is powered by VDDIO and current consumption on VDDBU is about zero (around 100
nA, typ.). When VDDIO is removed, the backup area of the device is supplied from VDDBU. Switching between
VDDIO and VDDBU is transparent to the user.
5.1.4
EMAFE Voltage Regulator
The SAM4CM series embeds a 2.8V voltage regulator to supply its Energy Metering Analog Front-End (the VDDA
pin). This regulator is under software control. When the EMAFE voltage regulator is turned off, its output stage is
placed in High-impedance mode and thus can be forced by an external voltage source.
5.1.5
Typical Powering Schematics
The SAM4CM series supports 1.6V to 3.6V single-supply operation. Restrictions on this range may apply
depending on enabled features. Refer to the section “Electrical Characteristics”.
Note:
Figure 5-2
,
Figure 5-3
and
Figure 5-4
show simplified schematics of the power section.
VDDCORE
VDDIN_AFE
1.08V to 1.32V
3.00V to 3.60V
Core logic, processors, memories and analog peripherals supply.
EMAFE regulator input.
EMAFE regulator output (2.8V).
EMAFE analog functions power supply input.
VDDA
2.70 to 2.90V
Table 5-1.
Power Supply Voltage Ranges (Continued)