at91cap7e ATMEL Corporation, at91cap7e Datasheet - Page 484

• Manufacturer Part Number: at91cap7e
• Description: Customizable Microcontroller
• Manufacturer: ATMEL Corporation

33.4
The following characteristics are applicable to the operating temperature range: T
power supply, unless otherwise specified.
Table 33-5.
Notes:
Figure 33-2. 32kHz Crystal Connection
484
Symbol
1/(t
C
C
t
ST
CRYSTAL32
LEXT32
CP32KHz
32 kHz Crystal Oscillator Characteristics
1. R
2. C
3. Additional board load capacitance should be subtracted from C
(2)
AT91CAP7E
)
S
LEXT32
is the equivalent series resistance, C
32 kHz Oscillator Characteristics
Parameter
Crystal Oscillator Frequency
Crystal Load Capacitance
External Load Capacitance
Duty Cycle
Startup Time
is determined by taking into account internal parasitic and package load capacitance.
C C
C
X IN 3 2
XIN32
L E X T 3 2
LEXT32
3 2
Conditions
Crystal @ 32.768 kHz
C
C
R
R
R
R
2
L
3
CRYSTAL32
CRYSTAL32
S
S
S
S
is the equivalent load capacitance.
AT91CAP7
= 50 kΩ, C
= 50 kΩ, C
= 100 kΩ, C
= 100 kΩ, C
C
C R Y S T A L 3 2
CRYSTAL32
= 6 pF
= 12.5 pF
L
L
L
L
= 6pF
= 12.5 pF
L 3 2
= 6pF
= 12.5 pF
3
(3)
C
X O U T 3 2
XOUT32
(3)
L E X T 3 2
LEXT32
(1)
(1)
LEXT32
(1)
(1)
3 2
3 2
.
2
G N D B U
GNDBU
A
Min
= -40°C to 85°C and worst case of
40
6
32.768
Typ
21
8
1200
Max
12.5
300
900
600
60
8549A–CAP–10/08
Unit
kHz
ms
ms
ms
ms
pF
pF
pF
%