114
XMEGA C3 [DATASHEET]
8492F–AVR–07/2013
Table 33-83. External clock with prescaler (1)for system clock. Notes:
1.
System Clock Prescalers must be set so that maximum CPU clock frequency for device is not exceeded.
2.
The maximum frequency vs. supply voltage is linear between 1.6V and 2.7V, and the same applies for all other parameters with supply voltage conditions.
33.3.13.7 External 16MHz crystal oscillator and XOSC characteristics
Table 33-84. External 16MHz crystal oscillator and XOSC characteristics.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
1/t
CK
VCC = 1.6 - 1.8V
0
90
MHz
V
CC = 2.7 - 3.6V
0
142
tCK
Clock Period
V
CC = 1.6 - 1.8V
11
ns
VCC = 2.7 - 3.6V
7
tCH
Clock High Time
VCC = 1.6 - 1.8V
4.5
ns
V
CC = 2.7 - 3.6V
2.4
t
CL
Clock Low Time
VCC = 1.6 - 1.8V
4.5
ns
VCC = 2.7 - 3.6V
2.4
tCR
Rise Time (for maximum frequency)
V
CC = 1.6 - 1.8V
1.5
ns
VCC = 2.7 - 3.6V
1.0
tCF
Fall Time (for maximum frequency)
VCC = 1.6 - 1.8V
1.5
ns
V
CC = 2.7 - 3.6V
1.0
t
CK
Change in period from one clock cycle to the next
10
%
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
Cycle to cycle jitter
XOSCPWR=0
FRQRANGE=0
0
ns
FRQRANGE=1, 2, or 3
0
XOSCPWR=1
0
Long term jitter
XOSCPWR=0
FRQRANGE=0
0
FRQRANGE=1, 2, or 3
0
XOSCPWR=1
0
Frequency error
XOSCPWR=0
FRQRANGE=0
0.03
%
FRQRANGE=1
0.03
FRQRANGE=2 or 3
0.03
XOSCPWR=1
0.003
Duty cycle
XOSCPWR=0
FRQRANGE=0
50
FRQRANGE=1
50
FRQRANGE=2 or 3
50
XOSCPWR=1
50