Atmel SAM4L Xplained Pro Evaluation Kit Atmel ATSAM4L-XPRO ATSAM4L-XPRO Data Sheet
Product codes
ATSAM4L-XPRO
120
42023ES–SAM–07/2013
ATSAM4L8/L4/L2
9.7
Oscillator Characteristics
9.7.1
Oscillator 0 (OSC0) Characteristics
9.7.1.1
Digital Clock Characteristics
The following table describes the characteristics for the oscillator when a digital clock is applied
on XIN.
on XIN.
9.7.1.2
Crystal Oscillator Characteristics
The following table describes the characteristics for the oscillator when a crystal is connected
between XIN and XOUT as shown in
between XIN and XOUT as shown in
. The user must choose a crystal oscillator
where the crystal load capacitance
C
L
is within the range given in the table. The exact value of C
L
can be found in the crystal datasheet. The capacitance of the external capacitors (C
LEXT
) can
then be computed as follows:
where C
STRAY
is the capacitance of the pins and PCB,
C
SHUNT
is the shunt capacitance of the
crystal.
Table 9-22.
Digital Clock Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Units
f
CPXIN
XIN clock frequency
(1)
50
MHz
t
CPXIN
XIN clock duty cycle
40
60
%
t
STARTUP
Startup time
N/A
cycles
1.
These values are based on simulation. These values are not covered by test limits in production or characterization.
C
LEXT
2 C
L
C
STRAY
C
SHUNT
–
–
(
)
=
Table 9-23.
Crystal Oscillator Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
f
OUT
Crystal oscillator frequency
(1)
0.6
30
MHz
ESR
Crystal Equivalent Series Resistance
(2)
f = 0.455MHz, C
LEXT
= 100pF
SCIF.OSCCTRL.GAIN = 0
17000
Ω
f = 2MHz, C
LEXT
= 20pF
SCIF.OSCCTRL.GAIN = 0
2000
f = 4MHz, C
LEXT
= 20pF
SCIF.OSCCTRL.GAIN = 1
1500
f = 8MHz, C
LEXT
= 20pF
SCIF.OSCCTRL.GAIN = 2
300
f = 16MHz, C
LEXT
= 20pF
SCIF.OSCCTRL.GAIN = 3
350
f = 30MHz, C
LEXT
= 18pF
SCIF.OSCCTRL.GAIN = 4
45