xmega a3u - Elfa
xmega a3u - Elfa
xmega a3u - Elfa
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
XMEGA A3U<br />
36.14.8 External 32.768kHz crystal oscillator and TOSC characteristics<br />
Table 36-30.<br />
External 32.768kHz crystal oscillator and TOSC characteristics.<br />
Symbol Parameter Condition Min. Typ. Max. Units<br />
ESR/R1<br />
Recommended crystal equivalent<br />
series resistance (ESR)<br />
Note: 1. See Figure 36-4 for definition.<br />
Crystal load capacitance 6.5pF 60<br />
Crystal load capacitance 9.0pF 35<br />
C TOSC1 Parasitic capacitance TOSC1 pin 4.2<br />
C TOSC2 Parasitic capacitance TOSC2 pin 4.3<br />
Recommended safety factor<br />
capacitance load matched to<br />
crystal specification<br />
3<br />
kΩ<br />
pF<br />
Figure 36-4.<br />
TOSC input capacitance.<br />
C L1 C L2<br />
2<br />
TOSC1<br />
Device internal<br />
External<br />
TOSC<br />
32.768KHz crystal<br />
The parasitic capacitance between the TOSC pins is C L1 + C L2 in series as seen from the crystal<br />
when oscillating without external capacitors.<br />
8386B–AVR–12/11<br />
87