Datasheet

907
32142D–06/2013
ATUC64/128/256L3/4U
35.6.2 32KHz Crystal Oscillator (OSC32K) Characteristics
Figure 35-3 and the equation above also applies to the 32KHz oscillator connection. 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 then be found in the crystal datasheet.
Notes: 1. Nominal crystal cycles.
2. 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.
35.6.3 Phase Locked Loop (PLL) Characteristics
Note: 1. 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 35-12. 32 KHz Crystal Oscillator Characteristics
Symbol Parameter Conditions Min Typ Max Unit
f
OUT
Crystal oscillator frequency 32 768 Hz
t
STARTUP
Startup time R
S
= 60kOhm, C
L
= 9pF 30 000
(1)
cycles
C
L
Crystal load capacitance
(2)
612.5
pF
C
i
Internal equivalent load
capacitance
2
I
OSC32
Current consumption 0.6 µA
R
S
Equivalent series resistance
(2)
32 768Hz 35 85 kOhm
Table 35-13. Phase Locked Loop Characteristics
Symbol Parameter Conditions Min Typ Max Unit
f
OUT
Output frequency
(1)
40 240
MHz
f
IN
Input frequency
(1)
416
I
PLL
Current consumption 8 µA/MHz
t
STARTUP
Startup time, from enabling
the PLL until the PLL is
locked
f
IN
= 4MHz 200
µs
f
IN
= 16MHz 155