PIC18LF4455-I/PT Microchip Technology, PIC18LF4455-I/PT Datasheet - Page 188

• Manufacturer Part Number: PIC18LF4455-I/PT
• Description: IC PIC MCU FLASH 12KX16 44TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18LF4455-I/PT

• Core Size: 8-Bit
• Program Memory Size: 24KB (12K x 16)
• Core Processor: PIC
• Speed: 48MHz
• Connectivity: I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 35
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 13x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Controller Family/series: PIC18
• No. Of I/o's: 36
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 2048Byte
• Cpu Speed: 48MHz
• No. Of Timers: 4
• Processor Series: PIC18LF
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: SPI, I2C, EAUSART
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 35
• Number Of Timers: 4
• 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, DV164136, DM163025
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 13 Channel
• Package: 44TQFP
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 48 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

PIC18F2455/2550/4455/4550
17.6
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.
17.6.1
In Bus Power Only mode, all power for the application
is drawn from the USB (Figure 17-10). This is
effectively the simplest power method for the device.
In order to meet the inrush current requirements of the
USB 2.0 specifications, the total effective capacitance
appearing across V
than 10 μF. If not, some kind of inrush limiting is
required. For more details, see Section 7.2.4 of the
USB 2.0 specification.
According to the USB 2.0 specification, all USB devices
must also support a Low-Power Suspend mode. In the
USB Suspend mode, devices must consume no more
than 2.5 mA from the 5V V
The host signals the USB device to enter the Suspend
mode by stopping all USB traffic to that device for more
than 3 ms. This condition will cause the IDLEIF bit in
the UIR register to become set.
During the USB Suspend mode, the D+ or D- pull-up
resistor must remain active, which will consume some
of the allowed suspend current: 2.5 mA budget.
FIGURE 17-10:
17.6.2
In Self-Power Only mode, the USB application provides
its own power, with very little power being pulled from
the USB. Figure 17-11 shows an example. Note that an
attach indication is added to indicate when the USB
has been connected and the host is actively powering
V
In order to meet compliance specifications, the USB
module (and the D+ or D- pull-up resistor) should not
be enabled until the host actively drives V
of the I/O pins may be used for this purpose.
DS39632E-page 186
BUS
.
V
~5V
BUS
USB Power Modes
BUS POWER ONLY
SELF-POWER ONLY
BUS
BUS POWER ONLY
and ground must be no more
BUS
line of the USB cable.
V
V
V
USB
DD
SS
BUS
high. One
The application should never source any current onto
the 5V V
FIGURE 17-11:
17.6.3
Some applications may require a dual power option.
This allows the application to use internal power pri-
marily, but switch to power from the USB when no inter-
nal power is available. Figure 17-12 shows a simple
Dual Power with Self-Power Dominance example,
which automatically switches between Self-Power Only
and USB Bus Power Only modes.
Dual power devices also must meet all of the special
requirements for inrush current and Suspend mode
current and must not enable the USB module until
V
ments, see Section 17.6.1 “Bus Power Only” and
Section 17.6.2 “Self-Power Only”.
Additionally, dual power devices must never source
current onto the 5V V
FIGURE 17-12:
BUS
V
V
Note:
SELF
~5V
~5V
BUS
100 kΩ
is driven high. For descriptions of those require-
BUS
V
V
100 kΩ
SELF
~5V
~5V
BUS
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.
pin of the USB cable.
100 kΩ
Attach Sense
BUS
SELF-POWER ONLY
DUAL POWER EXAMPLE
Attach Sense
© 2009 Microchip Technology Inc.
100 kΩ
pin of the USB cable.
I/O pin
V
V
V
USB
DD
SS
I/O pin
V
V
V
DD
USB
SS