PIC18F86J50-I/PT Microchip Technology, PIC18F86J50-I/PT Datasheet - Page 332

• Manufacturer Part Number: PIC18F86J50-I/PT
• Description: IC PIC MCU FLASH 32KX16 80TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F86J50-I/PT

• Core Size: 8-Bit
• Program Memory Size: 64KB (32K x 16)
• Oscillator Type: Internal
• Core Processor: PIC
• Speed: 48MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 65
• Program Memory Type: FLASH
• Ram Size: 3.8K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 12x10b
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-TFQFP
• Controller Family/series: PIC18
• No. Of I/o's: 65
• Ram Memory Size: 3904Byte
• Cpu Speed: 48MHz
• No. Of Timers: 5
• No. Of: RoHS Compliant
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 3904 B
• Interface Type: I2C, MSSP, SPI, EUSART
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 65
• Number Of Timers: 5
• 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, DM183022, DM183032
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 12 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC162087 - HEADER MPLAB ICD2 18F87J50 68/84MA180021 - MODULE PLUG-IN 18F87J50 FS USBAC164328 - MODULE SKT FOR 80TQFP
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

PIC18F87J50 FAMILY
22.6.3
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 22-11 shows a simple Dual
Power with Self-Power Dominance mode example,
which automatically switches between Self-Power Only
and USB Bus Power Only modes.
Dual power devices must also meet all of the special
requirements for inrush current and Suspend mode
current and must not enable the USB module until
V
Only” and Section 22.6.2 “Self-Power Only” for
descriptions of those requirements. Additionally, dual
power devices must never source current onto the 5V
V
FIGURE 22-11:
DS39775C-page 332
V
BUS
BUS
V
~3.3V
~5V
BUS
Note:
SELF
Low I
Regulator
pin of the USB cable.
is driven high. See Section 22.6.1 “Bus Power
100 kΩ
Q
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.
3.3V
100 kΩ
DUAL POWER EXAMPLE
Attach Sense
I/O pin
V
V
V
DD
USB
SS
22.6.4
The USB transceiver consumes a variable amount of
current depending on the characteristic impedance of
the USB cable, the length of the cable, the V
voltage and the actual data patterns moving across the
USB cable. Longer cables have larger capacitances
and consume more total energy when switching output
states.
Data patterns that consist of “IN” traffic consume far
more current than “OUT” traffic. IN traffic requires the
PIC
traffic requires that the host drive the USB cable.
The data that is sent across the USB cable is NRZI
encoded. In the NRZI encoding scheme, ‘0’ bits cause
a toggling of the output state of the transceiver (either
from a “J” state to a “K” state, or vise versa). With the
exception of the effects of bit-stuffing, NRZI encoded ‘1’
bits do not cause the output state of the transceiver to
change. Therefore, IN traffic consisting of data bits of
value, ‘0’, cause the most current consumption, as the
transceiver must charge/discharge the USB cable in
order to change states.
More details about NRZI encoding and bit-stuffing can
be found in the USB 2.0 specification’s section 7.1,
although knowledge of such details is not required to
make USB applications using the PIC18F87J10 family
of microcontrollers. Among other things, the SIE han-
dles bit-stuffing/unstuffing, NRZI encoding/decoding
and CRC generation/checking in hardware.
The total transceiver current consumption will be
application-specific. However, to help estimate how
much current actually may be required in full-speed
applications, Equation 22-1 can be used.
Example 22-2 shows how this equation can be used for
a theoretical application.
®
device to drive the USB cable, whereas OUT
USB TRANSCEIVER CURRENT
CONSUMPTION
© 2009 Microchip Technology Inc.
USB
supply