Manual

963
6264A–CAP–21-May-07
AT91CAP9S500A/AT91CAP9S250A
47.5 12 MHz Main Oscillator Characteristics
The following characteristics are applicable to the operating temperature range: T
A
= -40°C to 85°C and worst case of
power supply, unless otherwise specified.
Note: 1. Additional board load capacitance should be subtracted from C
LEXT
.
Figure 47-2. 12 MHz Crystal Connection
Table 47-7 gives the characteristics that the crystal must satisfy for correct operation with the oscillator.
Table 47-8 gives the Electrical Characteristics of the XIN pin when the oscillator is in Bypass Mode.
Table 47-6. Main Oscillator Characteristics
Symbol Parameter Conditions Min Typ Max Unit
1/(t
CPMAIN
) Crystal Oscillator Frequency 8 12 16 MHz
C
CRYSTAL
Crystal Load Capacitance 15 20 pF
C
LEXT
External Load Capacitance
C
CRYSTAL
= 15 pF
(1)
25
pF
C
CRYSTAL
= 20 pF
(1)
35
Duty Cycle 40 50 60 %
t
ST
Startup Time 2ms
I
DDST
Standby Current Consumption Standby mode 2 µA
P
ON
Drive Level 150 µW
I
DD ON
Current Dissipation @ 12MHz 450 700 µA
I
BYPASS
Bypass Current Dissipation 3.6 6.2 µW/MHz
Table 47-7. Crystal Characteristics
Symbol Parameter Conditions Min Typ Max Unit
ESR Equivalent Series Resistor Rs 60 Ω
C
M
Motional Capacitance 5 9 fF
C
S
Shunt Capacitance 7pF
Table 47-8. XIN Clock Electrical Characteristics in Bypass Mode
Symbol Parameter Conditions Min Max Units
1/(t
CPXIN
) XIN Clock Frequency 50 MHz
t
CPXIN
XIN Clock Period 20 ns
t
CHXIN
XIN Clock High Half-period 0.4 x t
CPXIN
0.6 x t
CPXIN
XIN XOUT
C
LEXT
C
LEXT
C
CRYSTAL
AT91CAP9
GNDUPLL