PIC18F27J53T-I/SO Microchip Technology, PIC18F27J53T-I/SO Datasheet - Page 38

• Manufacturer Part Number: PIC18F27J53T-I/SO
• Description: 28-pin, USB, 128KB Flash, 4KB RAM, 12 MIPS, 12-bit ADC, NanoWatt XLP 28 SOIC .30
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F27J53T-I/SO

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: I²C, LIN, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 128KB (64K x 16)
• Program Memory Type: FLASH
• Ram Size: 3.8K x 8
• Voltage - Supply (vcc/vdd): 2.15 V ~ 3.6 V
• Data Converters: A/D 10x10b/12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 3.8 KB
• Interface Type: I2C, SPI, USART
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 16
• Number Of Timers: 8
• Operating Supply Voltage: 2.15 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

PIC18F47J53 FAMILY
3.2.3
The EC and ECPLL Oscillator modes require an
external clock source to be connected to the OSC1 pin.
There is no oscillator start-up time required after a
Power-on Reset (POR) or after an exit from Sleep
mode.
In the EC Oscillator mode, the oscillator frequency
divided by 4, is available on the OSC2 pin. In the
ECPLL Oscillator mode, the PLL output, divided by 4,
is available on the OSC2 pin. This signal may be used
for test purposes or to synchronize other logic.
Figure 3-3 displays the pin connections for the EC
Oscillator mode.
FIGURE 3-3:
3.2.4
PIC18F47J53 family devices include a PLL circuit. This
is provided specifically for USB applications with lower
speed oscillators and can also be used as a
microcontroller clock source.
The PLL can be enabled in HSPLL, ECPLL,
INTOSCPLL and INTOSCPLLO Oscillator modes by
setting the PLLEN bit (OSCTUNE<6>). It is designed
to produce a fixed 96 MHz reference clock from a
fixed 4 MHz input. The output can then be divided and
used for both the USB and the microcontroller core
clock. Because the PLL has a fixed frequency input
and output, there are eight prescaling options to
match the oscillator input frequency to the PLL. This
prescaler allows the PLL to be used with crystals, res-
onators and external clocks, which are integer multiple
frequencies of 4 MHz. For example, a 12 MHz crystal
could be used in a prescaler Divide-by-Three mode to
drive the PLL.
DS39964B-page 38
Clock from
Ext. System
EXTERNAL CLOCK INPUT
PLL FREQUENCY MULTIPLIER
F
OSC
/4
EXTERNAL CLOCK INPUT
OPERATION (EC AND
ECPLL CONFIGURATION)
OSC1/CLKI
OSC2/CLKO
PIC18F47J53
Preliminary
There is also a CPU divider, which can be used to derive
the microcontroller clock from the PLL. This allows the
USB peripheral and microcontroller to use the same
oscillator input and still operate at different clock speeds.
The CPU divider can reduce the incoming frequency by
a factor of 1, 2, 3 or 6.
3.2.5
The PIC18F47J53 family devices include an internal
oscillator block which generates two different clock
signals; either can be used as the microcontroller’s
clock source. The internal oscillator may eliminate the
need for external oscillator circuits on the OSC1 and/or
OSC2 pins.
The main output (INTOSC) is an 8 MHz clock source
which can be used to directly drive the device clock. It
also drives the INTOSC postscaler which can provide a
range of clock frequencies from 31 kHz to 8 MHz.
Additionally, the INTOSC may be used in conjunction
with the PLL to generate clock frequencies up to
48 MHz.
The other clock source is the internal RC oscillator
(INTRC) which provides a nominal 31 kHz output.
INTRC is enabled if it is selected as the device clock
source. It is also enabled automatically when any of the
following are enabled:
• Power-up Timer
• Fail-Safe Clock Monitor
• Watchdog Timer
• Two-Speed Start-up
These features are discussed in larger detail in
Section 28.0 “Special Features of the CPU”.
The clock source frequency (INTOSC direct, INTRC
direct or INTOSC postscaler) is selected by configuring
the IRCF bits of the OSCCON register (page 43).
INTERNAL OSCILLATOR BLOCK
 2010 Microchip Technology Inc.