Datasheet

50
32099G–06/2011
AT32UC3L016/32/64
7.7 Oscillator Characteristics
7.7.1 Oscillator 0 (OSC0) Characteristics
7.7.1.1 Digital Clock Characteristics
The following table describes the characteristics for the oscillator when a digital clock is applied
on XIN.
7.7.1.2 Crystal Oscillator Characteristics
The following table describes the characteristics for the oscillator when a crystal is connected
between XIN and XOUT as shown in Figure 7-3. 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
PCB
is the capacitance of the PCB and C
i
is the internal equivalent load capacitance.
Notes: 1. Please refer to the SCIF chapter for details.
2. Nominal crystal cycles.
3. These values are based on simulation and characterization of other AVR microcontrollers manufactured in the same pro-
cess technology. These values are not covered by test limits in production.
Table 7-11. Digital Clock Characteristics
Symbol Parameter Conditions Min Typ Max Units
f
CPXIN
XIN clock frequency 50 MHz
t
CPXIN
XIN clock duty cycle 40 60 %
t
STARTUP
Startup time 0 cycles
C
IN
XIN input capacitance
TQFP48 package 7.0
pF
QFN48 package 6.7
C
LEXT
2C
L
C
i
–()C
PCB
–=
Table 7-12. Crystal Oscillator Characteristics
Symbol Parameter Conditions Min Typ Max Unit
f
OUT
Crystal oscillator frequency 0.45 10 16 MHz
C
L
Crystal load capacitance 6 18
pF
C
i
Internal equivalent load capacitance 2
t
STARTUP
Startup time SCIF.OSCCTRL.GAIN = 2
(1)
30 000
(2)
cycles
I
OSC
Current consumption
Active mode, f = 0.45MHz,
SCIF.OSCCTRL.GAIN = 0
30
µA
Active mode, f = 10MHz,
SCIF.OSCCTRL.GAIN = 2
170