Datasheet

78
XMEGA C3 [DATASHEET]
8492F–AVR–07/2013
Note: 1. Numbers for negative impedance are not tested in production but guaranteed from design and characterization.
33.1.13.8 External 32.768kHz crystal oscillator and TOSC characteristics
Table 33-27. External 32.768kHz crystal oscillator and TOSC characteristics.
Note: See Figure 33-4 for definition.
Figure 33-4. TOSC input capacitance.
The parasitic capacitance between the TOSC pins is C
L1
+ C
L2
in series as seen from the crystal when oscillating without
external capacitors.
C
XTAL1
Parasitic capacitance
XTAL1 pin
5.9
pF
C
XTAL2
Parasitic capacitance
XTAL2 pin
8.3
C
LOAD
Parasitic capacitance load 3.5
Symbol Parameter Condition Min. Typ. Max. Units
ESR/R1
Recommended crystal equivalent
series resistance (ESR)
Crystal load capacitance 6.5pF 60
k
Crystal load capacitance 9.0pF 35
Crystal load capacitance 12pF 28
C
TOSC1
Parasitic capacitance TOSC1 pin 3.5
pF
C
TOSC2
Parasitic capacitance TOSC2 pin 3.5
Recommended safety factor
capacitance load matched to
crystal specification
3
Symbol Parameter Condition Min. Typ. Max. Units
C
L1
C
L2
2CS
O
T
1
CS
O
T
Device internal
External