
PIC18F85J11 FAMILY
DS39774D-page 394
2010 Microchip Technology Inc.
B.1
Power Requirement Differences
The
most
significant
difference
between
the
PIC18F85J11 and PIC18F8722 device families is the
power requirements. PIC18F85J11 devices are
designed on a smaller process; this results in lower
maximum voltage and higher leakage current.
The operating voltage range for PIC18F85J11 devices is
2.0V to 3.6V. In addition, these devices have split power
requirements: one for the core logic and one for the I/O.
One of the VDD pins is separated for the core logic supply,
VDDCORE. This pin has specific voltage and capacitor
The current specifications for PIC18F85J11 devices
are yet to be determined.
B.2
Pin Differences
There are several differences in the pinout between the
PIC18F85J11 and the PIC18F8722 families:
Input voltage tolerance
Output current capabilities
Available I/O
Pins on the PIC18F85J11 that have digital only input
capability will tolerate voltages up to 5.5V and are thus
complete list.
In addition to input differences, there are output differ-
ences as well. PIC18F85J11 devices have three
classes of pin output current capability: high, medium
and low. Not all I/O pins can source or sink equal levels
of current. Only PORTB and PORTC support the
25 mA source/sink capability that is supported by all
complete list of output capabilities.
There are additional differences in how some pin func-
tions are implemented on PIC18F85J11 devices. First,
the MCLR pin is dedicated only to MCLR and cannot be
configured as an input (RG5). Finally, RF0 does not
exist on PIC18F85J11 devices.
All of these pin differences (including power pin
differences) should be accounted for when making a
conversion between PIC18F8722 and PIC18F85J11
devices.
B.3
Oscillator Differences
PIC18F8722 and PIC18F85J11 family devices share a
similar range of oscillator options. The major difference
is that PIC18F85J11 family devices support a smaller
number of primary (external) oscillator options, namely
HS and EC Oscillator modes.
While both device families have an internal PLL that
can be used with the primary oscillators, the PLL for the
PIC18F85J11 family is not enabled as a device
configuration option. Instead, it must be enabled in
software.
The clocking differences should be considered when
making a conversion between the PIC18F8722 and
PIC18F85J11 device families.
B.4
Peripherals
Peripherals must also be considered when making a
conversion between the PIC18F85J11 and the
PIC18F8722:
External Memory Bus: The External Memory
Bus (EMB) on the PIC18F85J11 does not support
Microcontroller mode; however, it does support
external address offset.
A/D Converter: There are only 12 channels on
PIC18F85J11 devices. The converters for these
devices also require a calibration step prior to
normal operation.
Data EEPROM: PIC18F85J11 devices do not
have this module.
BOR: PIC18F85J11 devices do not have a
programmable BOR. Simple Brown-out Reset
capability is provided through the use of the
internal voltage regulator.
LVD: PIC18F85J11 devices do not have a
separate programmable LVD module. Simple,
Low-Voltage Detection capability with a configu-
rable interrupt is provided through the use of the
internal voltage regulator.