17
SAM4CP [DATASHEET]
43051E–ATPL–08/14
5.1.5.3 Single Power Supply using One Main Battery and LCD Controller in Backup Mode
Figure 5-4
below shows a typical power supply scheme when the system needs to continue working and/or has to
maintain display in backup mode when the main voltage is not present.
In this power supply scheme, the SAM4CP can wake up both from an internal wake-up source, such as RTT, RTC and
VDDIO Supply Monitor, and from an external source, such as generic wake-up pins (WKUPx), anti-tamper inputs (TMPx)
or force wake-up (FWUP).
Note that PLC transceiver is not functional when working in backup mode.
Note:
The VDDIO supply monitor only wakes up the device from Backup mode on a negative-going VDDIO supply (as
system alert). Thus, the supply monitor cannot be used to wake up the device when the VDDIO supply is rising
at power cycle. See the Supply Controller section for more information about the VDDIO supply monitor.
Figure 5-4.
Single Power Supply using Battery and LCD Controller in Backup Mode
Notes: 1.
VDDIO corresponds to the following pins: 37, 64, 90, 105, 120, 139, 156 and 171.
VDDIO corresponds to the following pins: 1, 59, 62, 88 and 136.
Internal LCD Voltage Regulator can be disabled to save its operating current. VDDLCD must then be pro-
vided externally.
The STATE output of the power switch indicates to the MCU that the main supply is back and forces the sys-
tem to wake up.
2.
3.
4.
- 10-bit ADC
- Temp. Sensor
- Voltage Ref.
Automatic
Power Switch
Backup Region
RTC, RTT
and
Backup Registers
VDDIN
Core Voltage
Regulator
VDDOUT
Main Supply
(3.0V-3.6V)
VDDCORE
VDDBU
VDDPLL
LCD Voltage
Regulator
(3)
VDDLCD
VDDIO
(2)
Main Supply
Voltage
Regulator
IN
OUT
ON/OFF
PRIME PLC
Transceiver
LCD Buffers
+
LCD Switch Array
VDDIN AN
PLC Analog
Voltage
Regulator
VDDOUT AN
ADC PLC
VDDIN PLC
VDDOUT PLC
VDDPLL PLC
Shutdown (SHDN)
(5)
Force Wake-Up (FWUP)
(4)
STATE = 0 when main supply is OFF
Automatic
Power Switch
STATE
+
-
Battery
Generic Wake-Up pin (WKUPx)
VDDIO
(1)
PLC Digital
Voltage
Regulator
NRST
(6)
to PLL INIT