ATA6613 ATMEL Corporation, ATA6613 Datasheet - Page 55

• Manufacturer Part Number: ATA6613
• Description: Ata6613
• Manufacturer: ATMEL Corporation

6.6.4
9111C–AUTO–02/08
Full Swing Crystal Oscillator
Pins XTAL1 and XTAL2 are input and output, respectively, of an inverting amplifier which can be
configured for use as an On-chip Oscillator, as shown in
crystal or a ceramic resonator may be used.
This Crystal Oscillator is a full swing oscillator, with rail-to-rail swing on the XTAL2 output. This is
useful for driving other clock inputs and in noisy environments. The current consumption is
higher than the
Oscillator will only operate for V
C1 and C2 should always be equal for both crystals and resonators. The optimal value of the
capacitors depends on the crystal or resonator in use, the amount of stray capacitance, and the
electromagnetic noise of the environment. Some initial guidelines for choosing capacitors for
use with crystals are given in
ues given by the manufacturer should be used.
The operating mode is selected by the fuses CKSEL3..1 as shown in
Table 6-8.
Notes:
Figure 6-13. Crystal Oscillator Connections
Frequency Range
1. The frequency ranges are preliminary values. Actual values are TBD.
2. If 8 MHz frequency exceeds the specification of the device (depends on V
Fuse can be programmed in order to divide the internal frequency by 8. It must be ensured
that the resulting divided clock meets the frequency specification of the device.
0.4 - 20
Full Swing Crystal Oscillator Operating Modes
“Low Power Crystal Oscillator” on page
(1)
(MHz)
Table 6-9 on page
CC
= 2.7 - 5.5V.
CKSEL3..1
C2
C1
011
56. For ceramic resonators, the capacitor val-
Recommended Range for Capacitors C1
XTAL2
XTAL1
GND
Figure 6-12 on page
53. Note that the Full Swing Crystal
ATA6612/ATA6613
(2)
and C2 (pF)
Table
12 - 22
6-8.
53. Either a quartz
CC
), the CKDIV8
55