PIC18F2525 MICROCHIP [Microchip Technology], PIC18F2525 Datasheet - Page 25

• Manufacturer Part Number: PIC18F2525
• Description: 28/40/44-Pin Enhanced Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

2.0
2.1
PIC18F2525/2620/4525/4620 devices can be operated
in ten different oscillator modes. The user can program
the configuration bits, FOSC3:FOSC0, in Configuration
Register 1H to select one of these ten modes:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. ECIO
2.2
In XT, LP, HS or HSPLL Oscillator modes, a crystal or
ceramic resonator is connected to the OSC1 and
OSC2 pins to establish oscillation. Figure 2-1 shows
the pin connections.
The oscillator design requires the use of a parallel cut
crystal.
 2004 Microchip Technology Inc.
Note:
LP
XT
HS
HSPLL High-Speed Crystal/Resonator
RC
RCIO
INTIO1 Internal Oscillator with F
INTIO2 Internal Oscillator with I/O on RA6
EC
OSCILLATOR
CONFIGURATIONS
Oscillator Types
Crystal Oscillator/Ceramic
Resonators
Use of a series cut crystal may give a fre-
quency out of the crystal manufacturer’s
specifications.
Low-Power Crystal
Crystal/Resonator
High-Speed Crystal/Resonator
with PLL enabled
External Resistor/Capacitor with
F
External Resistor/Capacitor with I/O
on RA6
on RA6 and I/O on RA7
and RA7
External Clock with F
External Clock with I/O on RA6
OSC
/4 output on RA6
OSC
OSC
/4 output
/4 output
PIC18F2525/2620/4525/4620
Preliminary
FIGURE 2-1:
TABLE 2-1:
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
See the notes following Table 2-2 for additional
information.
Note 1: See Table 2-1 and Table 2-2 for initial values of
DD
Mode
XT
and temperature range for the application.
C1
C2
2: A series resistor (R
3: R
(1)
(1)
Typical Capacitor Values Used:
C1 and C2.
strip cut crystals.
F
3.58 MHz
4.19 MHz
XTAL
R
varies with the oscillator mode chosen.
4 MHz
4 MHz
S
Freq
(2)
CAPACITOR SELECTION FOR
CERAMIC RESONATORS
OSC2
OSC1
CRYSTAL/CERAMIC
RESONATOR OPERATION
(XT, LP, HS OR HSPLL
CONFIGURATION)
S
OSC1
) may be required for AT
15 pF
15 pF
30 pF
50 pF
R
F
(3)
DS39626B-page 23
PIC18FXXXX
Sleep
To
OSC2
Internal
Logic
15 pF
15 pF
30 pF
50 pF