ATXMEGA128B1_14 Datasheet, PDF (87/142 Pages) ATMEL Corporation – 8/16-bit Atmel XMEGA B1 Microcontroller

Symbol Parameter
Condition
C_XTAL1
Parasitic capacitance
C_XTAL2
Parasitic capacitance
C_LOAD
Parasitic capacitance load
Note:
1. Numbers for negative impedance are not tested but guaranteed from design and characterization.
Min.
Typ.
5.9
8.3
3.5
Max.
Units
pF
36.14.8 External 32.768kHz crystal oscillator and TOSC characteristics
Table 36-28. External 32.768kHz crystal oscillator and TOSC characteristics.
Symbol Parameter
Condition
Min
Typ
Max Units
ESR/R1
Recommended crystal equivalent
series resistance (ESR)
Crystal load capacitance 6.5pF
Crystal load capacitance 9.0pF
Crystal load capacitance 12.0pF
60
35
k
28
C_{IN_TOSC} Input capacitance between TOSC pins
Normal mode
Low power mode
3.5
pF
3.5
Recommended Safety factor
capacitance load matched to
crystal specification
3
Long term Jitter (SIT)
0
%
Note:
1. See Figure 36-4 on page 87 for definition
Figure 36-4. TOSC input capacitance
TOSC1
C_L1
C_L2
Device internal
External
TOSC2
32.768 kHz crystal
The input capacitance between the TOSC pins is C_L1 + C_L2 in series as seen from the crystal when oscillating without
external capacitors.
XMEGA B1 [DATASHEET] 87
Atmel-8330F-AVR-ATxmega64B1-128B1_datasheet–02/2014