Datasheet

DRAFT
SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
1396
45.4.4 32.768 kHz Crystal Characteristics
45.4.5 32.768 kHz XIN32 Clock Input Characteristics in Bypass Mode
Note: 1. These characteristics apply only when the 32.768 kHz crystal oscillator is in Bypass mode (i.e., when
SUPC_MR.OSCBYPASS = 1 and SUPC_CR.XTALSEL = 1.)
Figure 45-13. XIN32 Clock Timing
Table 45-18. Crystal Characteristics
Symbol Parameter Conditions Min Typ Max Unit
ESR Equivalent Series Resistor (R
S
)
Crystal @ 32.768 kHz
50 100 kΩ
C
m
Motional capacitance 0.6 3 fF
C
SHUNT
Shunt capacitance 0.6 2 pF
Table 45-19. XIN32 Clock Electrical Characteristics (In Bypass Mode)
Symbol Parameter Conditions Min Max Unit
1/(t
CPXIN32
) XIN32 Clock Frequency
(1)
44 kHz
t
CPXIN32
XIN32 Clock Period
(1)
22 µs
t
CHXIN32
XIN32 Clock High Half-period
(1)
11 µs
t
CLXIN32
XIN32 Clock Low Half-period
(1)
11 µs
t
CLCH
Rise Time 400 ns
t
CHCL
Fall Time 400 ns
C
IN
XIN32 Input Capacitance 6 pF
R
IN
XIN32 Pull-down Resistor 3 5 MΩ
V
XIN32_IL
V
XIN32
Input Low-level Voltage -0.3 0.3 × V
DDBU
V
V
XIN32_IH
V
XIN32
Input High-level Voltage 0.7 × V
DDBU
V
DDBU
+ 0.3 V
t
CPXIN32
t
CLXIN32
t
CHXIN32
t
CLCH
t
CHCL
V
XIN32_IL
V
XIN32_IH