Datasheet

138
XMEGA D4 [DATASHEET]
8135P–AVR–01/2014
Note: 1. Numbers for negative impedance are not tested in production but guaranteed from design and characterization.
32.4.13.8 External 32.768kHz crystal oscillator and TOSC characteristics
Table 32-112. External 32.768kHz crystal oscillator and TOSC characteristics.
Note: 1. See Figure 32-25 for definition.
Figure 32-25.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
C
TOSC
Parasitic capacitance
Normal mode 4.7
pF
Low power mode 5.2
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
32.768KHz crystal