PIC18F4431-E/ML Microchip Technology, PIC18F4431-E/ML Datasheet - Page 133

• Manufacturer Part Number: PIC18F4431-E/ML
• Description: IC MCU FLASH 8KX16 44QFN
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F4431-E/ML

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, Power Control PWM, QEI, POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 9x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 44-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

13.2
A crystal oscillator circuit is built in-between pins, T1OSI
(input) and T1OSO (amplifier output). It is enabled by
setting control bit, T1OSCEN (T1CON<3>). The oscilla-
tor is a low-power oscillator rated for 32 kHz crystals. It
will continue to run during all power-managed modes.
The circuit for a typical LP oscillator is shown in
Figure
for the Timer1 oscillator.
The user must provide a software time delay to ensure
proper start-up of the Timer1 oscillator.
FIGURE 13-3:
TABLE 13-1:
 2010 Microchip Technology Inc.
Osc Type
Note 1: Microchip suggests this value as a starting
Note:
LP
13-3.
2: Higher capacitance increases the stabil-
3: Since each resonator/crystal has its own
4: Capacitor values are for design guidance
Timer1 Oscillator
27 pF
27 pF
C1
C2
See the notes with
information about capacitor selection.
point in validating the oscillator circuit.
ity of the oscillator, but also increases the
start-up time.
characteristics, the user should consult
the resonator/crystal manufacturer for
appropriate
components.
only.
Table 13-1
32 kHz
32.768 kHz
XTAL
Freq
CAPACITOR SELECTION FOR
THE TIMER OSCILLATOR
EXTERNAL COMPONENTS
FOR THE TIMER1 LP
OSCILLATOR
shows the capacitor selection
values
Table 13-1
T1OSI
27 pF
T1OSO
C1
PIC18FXXXX
(1)
of
for additional
27 pF
PIC18F2331/2431/4331/4431
external
C2
(1)
13.3
The Timer1 oscillator for PIC18F2331/2431/4331/4431
devices incorporates an additional low-power feature.
When this option is selected, it allows the oscillator to
automatically reduce its power consumption when the
microcontroller is in Sleep mode. During normal device
operation, the oscillator draws full current. As high
noise environments may cause excessive oscillator
instability in Sleep mode, this option is best suited for
low noise applications, where power conservation is an
important design consideration.
The low-power option is enabled by clearing the
T1OSCMX bit (CONFIG3L<5>). By default, the option
is disabled, which results in a more or less constant
current draw for the Timer1 oscillator.
Due to the low-power nature of the oscillator, it may
also be sensitive to rapidly changing signals in close
proximity.
The oscillator circuit, shown in
located as close as possible to the microcontroller.
There should be no circuits passing within the oscillator
circuit boundaries other than V
Section 2.0 “Guidelines for Getting Started with
PIC18F Microcontrollers”
Timer1 Oscillator Layout
Considerations
for additional information
Figure
SS
DS39616D-page 133
or V
13-3, should be
DD
. Refer to