Figure 3-6. SAMA7G54-EK Shutdown and Reset Schematic
SHDN
NRST
J7
SHDN
R9
NRST_OUT H4
SAMA7G54
U4G
0402
1%
10k
R23
VDD_3V3
100R
R227
1
4
2
3
TL3301NF260QG
SW2
0.1uF
C239
GND
GND
VDD_3V3
10k
0402
1%
R4
1k
0402
5%
R3
MCP16502TAB-E/S8B
nRSTO
2
PWRHLD
8
U1
MPU
mikroBUS connectors
AN
1
RST
2
3
4
5
6
7
8
PWM 16
J10
nRST_MBUS
AN
1
RST
2
CS
3
SCK
4
MISO
5
MOSI
6
+3.3V
7
GND
8
PWM 16
INT 15
RX 14
TX 13
SCL 12
SDA 11
+5V 10
GND 9
mikroBUS HOST
J12
0R
06
03
R
19
8
0R
06
03
R
19
9
PMIC
MX66LM1G45GXDI00
10
0R
04
02
1%
R1
34
10
0R
04
02
1%
R1
36
U9
RESET#
A4
Octal SPI
Memory
RESET_N
42
kSZ9131RNXC
10
0R
04
02
1%
R
16
5
10
0R
04
02
1%
R16
6
U14
Gigabit
Ethernet
RST
24
KSZ8081RNAIA-TR
10
0R
04
02
1%
R
17
9
10
0R
04
02
1%
R
18
0
U15
Ethernet
10/100
1
2
3
BAT54AL
D
5
SD
MM
C1
_R
ST
N_
PB
28
0R
04
02
R
11
9
100R
0402
1%
R253
I0B
5
I1B
6
YB 7
IDTQS3VH257PAG
U27
U26
SAM3U
J27
JTAG Connector
EN
4
MIC94085YFT
U7
SD-CARD
Power Switch
3.1.4
Battery Unit
A 5.0V battery (supercapacitor C23) is implemented to permanently maintain the VDDBU voltage. An LDO (U2 -
MCP1711) is assigned to this supercap to decrease the VDDBU voltage down to 1.8V. That allows the VDDBU
domain power consumption to be decreased. This LDO has an ultra-low quiescent current and can drive a very low
load. For more information on the device, refer to the product
This function allows the user to shut down the MPU and the system, thus entering a low-power mode, and still keep
the custom configuration that was previously set in the MPU backup area.
Jumper JP1/J2 must be in place for proper operation of the MPU, and can be removed if the user wants to bring the
MPU back to the initial configuration, by resetting the General Purpose Backup Registers (GPBR).
Figure 3-7. SAMA7G54-EK Backup Circuitry
JP1
RB160MM-60TR
D4
100R
0402
5%
R13
GND
2.2uF
16V
0603
C22
GND
5V_MAIN
2.2uF
16V
0603
C21
GND
VDDBU
0.22F
5.5V
C23
1
2
HDR-2.54 Male 1x2
J2
Backup
GND
VIN
1
SHDN
3
GND 2
NC
4
VOUT 5
MCP1711/1.8V
U2
WARNING
Make sure the board is powered off before removing the JP1/J2 jumper.
3.1.5
Power Measurement
One Microchip DC power/energy monitor is embedded on the SAMA7G54-EK board and provides a four-channel
current sense monitoring ensured by the PAC1934 device.
The device communicates with the MPU via a Two-Wire Interface (TWI) and an alert output signal.
The PAC1934 is a four-channel power/energy monitor with current sensor amplifier and bus voltage monitors that
feed high resolution ADCs. A digital circuitry performs power calculations and energy accumulation. The PAC1934
SAMA7G54-EK
Function Blocks
©
2022 Microchip Technology Inc.
and its subsidiaries
User Guide
DS50003273A-page 13