5 12 mhz main oscillator characteristics – Rainbow Electronics AT91CAP9S250A User Manual
Page 963
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
gives the characteristics that the crystal must satisfy for correct operation with the oscillator.
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
25
pF
C
CRYSTAL
= 20 pF
35
Duty Cycle
40
50
60
%
t
ST
Startup Time
2
ms
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
7
pF
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