Datasheet

57
9166DS–AVR-01/12
AT32UC3C
Notes: 1. Please refer to the SCIF chapter for details.
7.6.2 32KHz Crystal Oscillator (OSC32K) Characteristics
7.6.2.1 Digital Clock Characteristics
The following table describes the characteristics for the oscillator when a digital clock is applied
on XIN32.
7.6.2.2 Crystal Oscillator Characteristics
Figure 7-2 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..
Table 7-8. Crystal Oscillator Characteristics
Symbol Parameter Conditions Min Typ Max Unit
f
OUT
Crystal oscillator frequency 0.4 20 MHz
C
i
Internal equivalent load capacitance 1.7 pF
t
STARTUP
Startup time
f
OUT
= 8MHz
SCIF.OSCCTRL.GAIN = 1
(1)
975 us
f
OUT
= 16MHz
SCIF.OSCCTRL.GAIN = 2
(1)
1100 us
Table 7-9. Digital 32KHz Clock Characteristics
Symbol Parameter Conditions Min Typ Max Units
f
CPXIN
XIN32 clock frequency 32.768 5000 KHz
t
CPXIN
XIN32 clock period 200 ns
t
CHXIN
XIN32 clock high half-priod 0.4 x t
CPXIN
0.6 x t
CPXIN
ns
t
CLXIN
XIN32 clock low half-priod 0.4 x t
CPXIN
0.6 x t
CPXIN
ns
C
IN
XIN32 input capacitance 2 pF
Table 7-10. 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
= 50 kOhm, C
L
= 12.5pF 2 s
C
L
Crystal load capacitance 6 15 pF
C
i
Internal equivalent load
capacitance
1.4 pF