Evaluation Kit Hardware
4-4
SAM3S-EK Development Board User Guide
11031A–ATARM–14-Dec-09
PLLACK, the output of the Divider and 60 to 130 MHz programmable PLL (PLLA)
PLLBCK, the output of the Divider and 60 to 130 MHz programmable PLL (PLLB)
4.3.4
Reset Circuitry
On-board NRST button BP1 provides an external reset control of the SAM3S.
The NRST pin is bidirectional. It is handled by the on-chip reset controller. It can be driven low to provide
a reset signal out to the external components. Conversely, it can be asserted low from the outside to
reset the microcontroller Core and the peripherals. The NRST pin integrates a permanent pull-up resistor
of about 100 kOhm to VDDIO.
On the SAM3S-EK board, the NRST signal is connected to the LCD module and JTAG port.
4.3.5
Power Supply and Management
The SAM3S-EK board is supplied with an external 5V DC block through input J9. It is protected by a
PolyZen diode MN9 and an LC combinatory filter MN10. The PolyZen is used in the event of an incorrect
power supply connection.
The adjustable LDO regulator MN12 is used for the 3.3V rail main supply. It powers all the 3.3V compo-
nents on the board.
Figure 4-4.
Power Block
The SAM3S4/2/1 product series has different types of power supply pins:
VDDIN pin:
Power for the internal voltage regulator, ADC, DAC, and analog comparator power supplies.
The voltage ranges from 1.8V to 3.6V.
VDDIO pins:
Power for the Peripherals I/O lines.
The voltage ranges from 1.62V to 3.6V.
VDDOUT pin:
Output of the internal voltage regulator.
VDDCORE pins:
Power for the core, including the processor, embedded memories and peripherals.
The voltage ranges from 1.62V to 1.95V.
VDDPLL pin:
Power for the PLL A, PLL B and 12 MHz oscillator.
The voltage ranges from 1.62V to 1.95V.
DGND
+5V
+5V
+
3
V
3
C75
100
u
F
+
C75
100
u
F
C65
22
u
F
+
C65
22
u
F
C64
100nF
C64
100nF
MN10
BNX002-01
MN10
BNX002-01
S
V
1
S
G
2
CV
3
CG1
4
CG2
5
CG
3
6
C76
100nF
C76
100nF
C66
22
u
F
+
C66
22
u
F
MN9
ZEN056V1
3
0A24L
S
MN9
ZEN056V1
3
0A24L
S
1
2
3
R92
102K 1%
R92
102K 1%
MN12
MIC29152W U
Micrel'
s
1.5A LDO, TO26
3
-5
MN12
MIC29152W U
Micrel'
s
1.5A LDO, TO26
3
-5
VIN
2
VOUT
4
S
D
1
GND1
3
ADJ
5
GND2
6
R
8
9
169K 1%
R
8
9
169K 1%
J9
MP179P 2.1mm
J9
MP179P 2.1mm
1
2
3
