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Figure 3-7. VDDFUSE Regulator
VDD_3V3
GND_POWER
VDDFUSE
EN_1
12
C16
1uF
C0603
U5
MIC5366-2.5YMT
MLF1x1mm
VIN
4
GND
2
VOUT
1
EN
3
E
P
A
D
5
C15
1uF
C0603
3.2.2.7
Backup Power Supply
The SAMA5D2-PTC-EK board requires a power source in order to permanently power the backup part of
the SAMA5D2 device (refer to SAMA5D2 Series datasheet). The super capacitor C17 sustains such
permanent power to VDDBU when all system power sources are off.
Figure 3-8. VDDBU Powering Options
(Super)-Capacitor
energy storage
VDDBU
GND_POWER
GND_POWER
VDD_3V3
C18
100nF
C0402
JP6
Header 1X2
1 2
+
C17
0.2F/3.3V
c117x68
D2
PMEG6010CEGWX
sod123
R14
100R-1%
R0402
D3
BAT54C
SOT23_123
3
1
2
3.2.3
Reset Circuitry
The reset sources for the SAMA5D2-PTC-EK board are:
•
Power-on reset from the power management unit,
•
Push button reset BP3,
•
JTAG or JLINK-OB reset from an in-circuit emulator.
Figure 3-9. Main Reset Control
STARTB
GND_POWER
VDD_MAIN_5V
VDD_3V3
NRST
R13
39K
R0402
R12
220K
R0402
R11
100K
R0402
D1
PMEG6010CEGWX
sod123
Q3
BSS138
SOT23_123
1
3
2
Q4
BC847C
SOT-23
1
3
2
C14
2.2uF
C0603
PowerGood VDD_1V25
3.2.4
Shutdown Circuitry
The SHDN signal, output of Shutdown Controller (SHDN), drives the shutdown request to the power
supply. This output signal is supplied by VDDBU, which is present in Backup mode.
The Shutdown Controller manages the main power supply and is connected to the ENABLE input pin of
the DC/DC converter providing the main power supplies of the system.
SAMA5D2-PTC-EK
Board Components
©
2017 Microchip Technology Inc.
DS50002709A-page 13