PIC18F25K80 MICROCHIP [Microchip Technology], PIC18F25K80 Datasheet - Page 60

• Manufacturer Part Number: PIC18F25K80
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F66K80 FAMILY
3.5
3.5.1
In HS or HSPLL Oscillator modes, a crystal or ceramic
resonator is connected to the OSC1 and OSC2 pins to
establish
connections.
The oscillator design requires the use of a crystal rated
for parallel resonant operation.
TABLE 3-2:
DS39977C-page 60
Capacitor values are for design guidance only.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
V
to the following application notes for oscillator-specific
information:
• AN588, “PIC
• AN826, “Crystal Oscillator Basics and Crystal
• AN849, “Basic PIC
• AN943, “Practical PIC
• AN949, “Making Your Oscillator Work”
See the notes following
information.
Note:
DD
Mode
Guide”
Selection for rfPIC
Design”
HS
and temperature range for the application. Refer
External Oscillator Modes
Typical Capacitor Values Used:
oscillation.
CRYSTAL OSCILLATOR/CERAMIC
RESONATORS (HS MODES)
Use of a crystal rated for series resonant
operation may give a frequency out of the
crystal manufacturer’s specifications.
16.0 MHz
8.0 MHz
Freq.
®
Microcontroller Oscillator Design
CAPACITOR SELECTION FOR
CERAMIC RESONATORS
®
®
and PIC
Oscillator Design”
Figure 3-4
®
Oscillator Analysis and
Table 3-3
OSC1
27 pF
22 pF
®
Devices”
shows
for additional
OSC2
27 pF
22 pF
the
Preliminary
pin
TABLE 3-3:
FIGURE 3-4:
Osc Type
Capacitor values are for design guidance only.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
V
Refer to the Microchip application notes cited in
Table 3-2
the
information.
DD
Note 1: See
Note 1: Higher capacitance increases the stability
HS
and temperature range for the application.
notes
C1
C2
2: A series resistor (R
3: R
2: Since each resonator/crystal has its own
3: Rs may be required to avoid overdriving
4: Always verify oscillator performance over
(1)
(1)
for oscillator specific information. Also see
C1 and C2.
strip cut crystals.
of oscillator but also increases the start-up
time.
characteristics, the user should consult
the resonator/crystal manufacturer for
appropriate
components.
crystals with low drive level specification.
the V
expected for the application.
F
following
varies with the oscillator mode chosen.
Crystal
20 MHz
XTAL
4 MHz
8 MHz
Table 3-2
Freq.
R
CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
DD
S
(2)
OSC1
OSC2
and temperature range that is
CRYSTAL/CERAMIC
RESONATOR OPERATION
(HS OR HSPLL
CONFIGURATION)
 2011 Microchip Technology Inc.
and
this
Typical Capacitor Values
Table 3-3
values
S
27 pF
22 pF
15 pF
) may be required for AT
R
C1
table
F
PIC18F66K80
(3)
Tested:
for initial values of
for
of
Sleep
additional
27 pF
22 pF
15 pF
external
To
Internal
Logic
C2