PIC18F2450-I/SO Microchip Technology, PIC18F2450-I/SO Datasheet - Page 151

• Manufacturer Part Number: PIC18F2450-I/SO
• Description: IC PIC MCU FLASH 8KX16 28SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F2450-I/SO

• Program Memory Type: FLASH
• Program Memory Size: 16KB (8K x 16)
• Package / Case: 28-SOIC (7.5mm Width)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: UART/USART, USB
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 23
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 10x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 768 B
• Interface Type: EUSART/USB
• Maximum Clock Frequency: 48 MHZ
• Number Of Programmable I/os: 23
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DM163014, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Package: 28SOIC W
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 48 MHz
• A/d Bit Size: 10 bit
• A/d Channels Available: 10
• Height: 2.31 mm
• Length: 17.87 mm
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2 V
• Width: 7.49 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164322 - MODULE SOCKET MPLAB PM3 28/44QFNDM163025 - PIC DEM FULL SPEED USB DEMO BRD
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

14.6
Many USB applications will likely have several different
sets of power requirements and configuration. The
most common power modes encountered are Bus
Power Only, Self-Power Only and Dual Power with
Self-Power Dominance. The most common cases are
presented here.
14.6.1
In Bus Power Only mode, all power for the application
is drawn from the USB (Figure 14-10). This is
effectively the simplest power method for the device.
FIGURE 14-10:
14.6.2
In Self-Power Only mode, the USB application provides
its own power, with very little power being pulled from
the USB. Figure 14-11 shows an example. Note that an
attach indication is added to indicate when the USB
has been connected.
FIGURE 14-11:
© 2007 Microchip Technology Inc.
USB Power Modes
V
V
V
100 kΩ
SELF
~5V
~5V
BUS
~5V
BUS
SELF-POWER ONLY
BUS POWER ONLY
Attach Sense
BUS POWER ONLY
SELF-POWER ONLY
100 kΩ
I/O pin
V
V
V
V
V
V
DD
USB
SS
USB
DD
SS
Preliminary
14.6.3
Some applications may require a dual power option.
This allows the application to use internal power prima-
rily, but switch to power from the USB when no internal
power is available. Figure 14-12 shows a simple Dual
Power with Self-Power Dominance example, which
automatically switches between Self-Power Only and
USB Bus Power Only modes.
FIGURE 14-12:
14.7
The USB module has specific clock requirements. For
full-speed operation, the clock source must be 48 MHz.
Even so, the microcontroller core and other peripherals
are not required to run at that clock speed or even from
the same clock source. Available clocking options are
described in detail in Section 2.3 “Oscillator Settings
for USB”.
14.8
Microchip provides a number of application-specific
resources, such as USB firmware and driver support.
Refer to www.microchip.com for the latest firmware and
driver support.
V
Note:
V
SELF
~5V
~5V
BUS
100 kΩ
Oscillator
USB Firmware and Drivers
PIC18F2450/4450
DUAL POWER WITH SELF-POWER
DOMINANCE
Users should keep in mind the limits for
devices drawing power from the USB.
According to USB Specification 2.0, this
cannot exceed 100 mA per low-power
device or 500 mA per high-power device.
100 kΩ
DUAL POWER EXAMPLE
Attach Sense
DS39760C-page 149
I/O pin
V
V
V
DD
USB
SS