1108
11100B–ATARM–31-Jul-12
SAM4S Series [Preliminary]
42.4.3
32.768 kHz Crystal Oscillator Characteristics
Note:
1. R
S
is the series resitor.
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.
42.4.4
32.768 kHz Crystal Characteristics
Table 42-17. 32.768 kHz Crystal Oscillator Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
F
req
Operating Frequency
Normal mode with crystal
32.768
KHz
Supply Ripple Voltage (on VDDIO)
Rms value, 10 KHz to 10 MHz
30
mV
Duty Cycle
40
50
60
%
Startup Time
Rs < 50K
Ω
Rs < 100K
Ω
C
crystal
= 12.5pF
C
crystal
= 6pF
C
crystal
= 12.5pF
C
crystal
= 6pF
900
300
1200
500
ms
Iddon
Current consumption
Rs < 50K
Ω
Rs < 100K
Ω
C
crystal
= 12.5pF
C
crystal
= 6pF
C
crystal
= 12.5pF
C
crystal
= 6pF
550
380
820
530
1150
980
1600
1350
nA
P
ON
Drive level
0.1
µW
R
f
Internal resistor
between XIN32 and XOUT32
10
M
Ω
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 42-18. Crystal Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
ESR
Equivalent Series Resistor (R
S)
Crystal @ 32.768 KHz
50
100
K
Ω
C
M
Motional capacitance
Crystal @ 32.768 KHz
0.6
3
fF
C
SHUNT
Shunt capacitance
Crystal @ 32.768 KHz
0.6
2
pF
Содержание SAM4S Series
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Страница 1142: ...1142 11100B ATARM 31 Jul 12 SAM4S Series Preliminary Figure 43 3 100 ball VFBGA Package Drawing ...
Страница 1143: ...1143 11100B ATARM 31 Jul 12 SAM4S Series Preliminary Figure 43 4 64 lead LQFP Package Drawing ...
Страница 1145: ...1145 11100B ATARM 31 Jul 12 SAM4S Series Preliminary Figure 43 5 64 lead QFN Package Drawing ...