Datasheet

135
XMEGA D3 [DATASHEET]
Atmel-8134N-ATxmega32D3-64D3-128D3-192D3-256D3-384D3_datasheet–03/2014
Notes: 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 32-114. External 32.768kHz crystal oscillator and TOSC characteristics.
Note: 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
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
32.768 kHz crystal