Datasheet

DRAFT
1397
SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
45.4.6 3 to 20 MHz Crystal Oscillator Characteristics
Figure 45-14. 3 to 20 MHz Crystal Oscillator Schematic
C
LEXT
= 2 × (C
crystal
- C
LOAD
- C
PCB
)
where:
C
PCB
is the capacitance of the printed circuit board (PCB) track layout from the crystal to the SAM3 pin.
Table 45-20. 3 to 20 MHz Crystal Oscillator Characteristics
Symbol Parameter Conditions Min Typ Max Unit
f
OSC
Operating Frequency Normal mode with crystal 3 16 20 MHz
f
OSC(bypass)
Operating Frequency In Bypass Mode External Clock on XIN 50 MHz
V
rip(VDDPLL)
Supply Ripple Voltage (on VDDPLL) RMS value, 10 kHz to 10 MHz 30 mV
Duty Cycle 40 50 60 %
t
START
Startup Time
3 MHz, C
SHUNT
= 3 pF
8 MHz, C
SHUNT
= 7 pF
12 to 16 MHz, C
SHUNT
= 7 pF
20 MHz, C
SHUNT
= 7 pF
14.5
4
1.4
1
ms
I
DDON
Current Consumption
3 MHz
8 MHz
12 to 16 MHz
20 MHz
150
150
300
400
250
250
450
550
µA
I
DD(standby)
Standby Current Consumption Standby mode @ 3.6V 5 nA
P
ON
Drive Level
3 MHz
8 MHz
12 MHz, 16 MHz, 20 MHz
15
30
50
µW
R
f
Internal Resistor Between XIN and XOUT 1 MΩ
C
LEXT
Maximum external capacitor on XIN and
XOUT
10 pF
C
crystal
Allowed Crystal Capacitance Load From crystal specification 12.5 17.5 pF
C
LOAD
Internal Equivalent Load Capacitance
Integrated Load Capacitance (XIN and
XOUT in series)
7.5 9.5 12 pF
XIN
XOUT
C
LEXT
C
LOAD
C
LEXT
C
crystal
SAM3
R = 1K if crystal frequency is lower than 8 MHz