PIC18F2431-I/SP Microchip Technology Inc., PIC18F2431-I/SP Datasheet - Page 24

• Manufacturer Part Number: PIC18F2431-I/SP
• Description: Microcontroller; 16 KB Flash; 768 RAM; 256 EEPROM; 24 I/O; 28-Pin-SPDIP
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F2431-I/SP

• A/d Inputs: 5-Channel, 10-Bit
• Cpu Speed: 10 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 24
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 28-pin SPDIP
• Programmable Memory: 16K Bytes
• Ram Size: 768 Bytes
• Speed: 40 MHz
• Timers: 1-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC18F2331/2431/4331/4431
TABLE 2-2:
DS39616B-page 22
Osc Type
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.
DD
Note 1: Higher capacitance increases the stability
XT
HS
LP
and temperature range for the application.
2: When operating below 3V V
3: Since each resonator/crystal has its own
4: Rs may be required to avoid overdriving
5: Always verify oscillator performance over
200 kHz
32 kHz
1 MHz
of oscillator, but also increases the start-
up time.
using certain ceramic resonators at any
voltage, it may be necessary to use the
HS mode or switch to a crystal oscillator.
characteristics, the user should consult
the resonator/crystal manufacturer for
appropriate
components.
crystals with low drive level specification.
the V
expected for the application.
200 kHz
Crystal
20 MHz
32 kHz
1 MHz
4 MHz
4 MHz
8 MHz
Freq
CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
DD
Crystals Used:
and temperature range that is
Typical Capacitor Values
values
33 pF
15 pF
33 pF
27 pF
27 pF
22 pF
15 pF
C1
Tested:
20 MHz
4 MHz
8 MHz
of
DD
, or when
33 pF
15 pF
33 pF
27 pF
27 pF
22 pF
15 pF
external
C2
Preliminary
An external clock source may also be connected to the
OSC1 pin in the HS mode, as shown in Figure 2-2.
FIGURE 2-2:
2.3
A Phase Locked Loop (PLL) circuit is provided as an
option for users who wish to use a lower frequency
crystal oscillator circuit, or to clock the device up to its
highest rated frequency from a crystal oscillator. This
may be useful for customers who are concerned with
EMI due to high-frequency crystals.
The HSPLL mode makes use of the HS mode oscillator
for frequencies up to 10 MHz. A PLL then multiplies the
oscillator output frequency by 4 to produce an internal
clock frequency up to 40 MHz.
The PLL is enabled only when the oscillator configura-
tion bits are programmed for HSPLL mode. If
programmed for any other mode, the PLL is not
enabled.
FIGURE 2-3:
Clock from
Ext. System
OSC2
OSC1
HSPLL
(from Configuration Register 1H)
HS Mode
Crystal
Osc
Open
HS Osc Enable
PLL Enable
F
F
EXTERNAL CLOCK INPUT
OPERATION (HS OSC
CONFIGURATION)
PLL BLOCK DIAGRAM
IN
OUT
4
 2003 Microchip Technology Inc.
OSC1
OSC2
Comparator
Loop
Filter
Phase
VCO
PIC18FXXXX
(HS Mode)
SYSCLK