PIC18F25J11-I/PT MICROCHIP [Microchip Technology], PIC18F25J11-I/PT Datasheet - Page 33

• Manufacturer Part Number: PIC18F25J11-I/PT
• Description: 28/44-Pin, Low-Power, High-Performance Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

2.2.2
In HS and HSPLL Oscillator modes, a crystal or
ceramic resonator is connected to the OSC1 and
OSC2 pins to establish oscillation. Figure 2-2 displays
the pin connections.
The oscillator design requires the use of a parallel cut
crystal.
FIGURE 2-2:
TABLE 2-2:
© 2009 Microchip Technology Inc.
Capacitor values are for design guidance only.
These capacitors were tested with the resonators
listed below for basic start-up and operation. These
values are not optimized.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
V
See the notes following Table 2-3 for additional
information.
Note 1:
Note:
DD
Mode
HS
and temperature range for the application.
C1
C2
2:
3:
(1)
(1)
Typical Capacitor Values Used:
CRYSTAL OSCILLATOR/CERAMIC
RESONATORS
Use of a series cut crystal may give a fre-
quency out of the crystal manufacturer’s
specifications.
See Table 2-2 and Table 2-3 for initial values
of C1 and C2.
A series resistor (R
strip cut crystals.
R
16.0 MHz
XTAL
R
F
8.0 MHz
S
varies with the selected oscillator mode.
Freq
(2)
Resonators Used:
CAPACITOR SELECTION FOR
CERAMIC RESONATORS
OSC2
OSC1
16.0 MHz
CRYSTAL/CERAMIC
RESONATOR OPERATION
(HS OR HSPLL
CONFIGURATION)
4.0 MHz
8.0 MHz
S
OSC1
27 pF
22 pF
R
) may be required for AT
PIC18F46J11
F
(3)
Sleep
OSC2
27 pF
22 pF
To
Internal
Logic
PIC18F46J11 FAMILY
TABLE 2-3:
An internal postscaler allows users to select a clock
frequency other than that of the crystal or resonator.
Frequency division is determined by the CPDIV
Configuration bits. Users may select a clock frequency
of the oscillator frequency, or 1/2, 1/3 or 1/6 of the
frequency.
Capacitor values are for design guidance only.
These capacitors were tested with the crystals listed
below for basic start-up and operation. These values
are not optimized.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
V
See the notes following this table for additional
information.
Osc Type
DD
Note 1: Higher capacitance not only increases
HS
and temperature range for the application.
2: Since each resonator/crystal has its own
3: Rs may be required to avoid overdriving
4: Always verify oscillator performance over
the stability 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.
20 MHz
Crystal
4 MHz
8 MHz
Freq
CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
DD
Crystals Used:
and temperature range that is
20 MHz
4 MHz
8 MHz
Typical Capacitor Values
values
27 pF
22 pF
15 pF
C1
Tested:
DS39932C-page 33
of
27 pF
22 pF
15 pF
external
C2