Atmel AT01080: XMEGA E Schematic Checklist [APPLICATION NOTE]
42087A
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AVR
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04/2013
7
Figure 3-3. Real-time oscillator without load capacitor.
Crystals specifying load capacitance (CL) higher than 3.0pF, require external capacitors applied as described in
Figure 3-4. Real-time oscillator with load capacitor.
32.768kHz
18pF
18pF
TOSC1
TOSC2
To find suitable load capacitance for a 32.768kHz crystal, please consult the crystal datasheet.
Table 3-4. External real-time oscillator checklist.
Signal name
Recommended pin connection
Description
TOSC1
Load capacitor 18pF
(1)(2)
Timer oscillator pin 1
TOSC2
Load capacitor 18pF
(1)(2)
Timer oscillator pin 2
Notes:
1. These values are given only as a typical example. Please refer to the crystal datasheet to determine the
capacitor value for the crystal used or refer to the applic” and “
2.
Load capacitors should be placed close to the crystal, GND and device oscillator pins.
