Data Sheet

1091
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181G–SAM-D21_Datasheet–09/2015
Figure A-4. Oscillator Connection
A.8.2 External 32kHz Crystal Oscillator (XOSC32K) Characteristics
Digital Clock Characteristics
The following table describes the characteristics for the oscillator when a digital clock is applied on XIN32 pin.
Table A-38. Digital Clock Characteristics
Crystal Oscillator Characteristics
Figure A-4 and the equation in “Crystal Oscillator (XOSC) Characteristics” on page 1088 also applies to the 32kHz
oscillator connection. The user must choose a crystal oscillator where the crystal load capacitance C
L
is within the range
given in the table. The exact value of C
L
can be found in the crystal datasheet.
C
SHUNT
L
M
R
M
C
M
C
STRAY
C
LEXT
C
LEXT
Xin
Crystal
Xout
Symbol Parameter Conditions Min. Typ. Max. Units
f
CPXIN32
XIN32 clock frequency
I
- 32.768 - kHz
I
XIN32 clock duty cycle
I
- 50 - %