Atmel SAM4S Xplained Pro Starter and Evaluation Kit ATSAM4S-XPRO ATSAM4S-XPRO Data Sheet
Product codes
ATSAM4S-XPRO
1145
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
44.5.3 32.768 kHz Crystal Oscillator Characteristics
Note:
1. R
S
is the series resistor.
C
LEXT
= 2x(
C
CRYSTAL
–
C
para
–
C
PCB
).
Where
C
PCB
is the capacitance of the printed circuit board (PCB) track layout from the crystal to the SAM4 pin.
44.5.4 32.768 kHz Crystal Characteristics
Table 44-27.
32.768 kHz Crystal Oscillator Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
f
req
Operating Frequency
Normal mode with crystal
32.768
kHz
Duty Cycle
40
50
60
%
Startup Time
Rs < 50 KΩ
Rs < 100 KΩ
C
crystal
= 12.5 pF
C
crystal
= 6 pF
C
crystal
= 12.5 pF
C
crystal
= 6 pF
—
—
900
300
300
1200
500
ms
I
DD_ON
Current Consumption
Rs < 50 KΩ
Rs < 100 KΩ
C
crystal
= 12.5 pF
C
crystal
= 6 pF
C
crystal
= 12.5 pF
C
crystal
= 6 pF
—
550
380
820
530
380
820
530
1150
980
1600
1350
1350
nA
P
ON
Drive Level
—
—
0.1
µW
R
f
Internal Resistor
Between XIN32 and XOUT32
—
10
MΩ
C
LEXT
Maximum External Capacitor
on XIN32 and XOUT32
—
—
20
pF
C
para
Internal Parasitic Capacitance
0.6
0.7
0.8
pF
XIN32
XOUT32
C
LEXT
C
LEXT
SAM4
Table 44-28.
Crystal Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
ESR
Equivalent Series Resistor (R
S)
Crystal @ 32.768 kHz
—
50
100
KΩ
C
M
Motional Capacitance
Crystal @ 32.768 kHz
0.6
—
3
fF
C
SHUNT
Shunt Capacitance
Crystal @ 32.768 kHz
0.6
—
2
pF