PIC18F64J90-I/PT Microchip Technology, PIC18F64J90-I/PT Datasheet - Page 299

• Manufacturer Part Number: PIC18F64J90-I/PT
• Description: Microcontroller
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F64J90-I/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, LVD, POR, PWM, WDT
• Number Of I /o: 51
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TFQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC162079 - HEADER MPLAB ICD2 18F85J90 64/80AC164327 - MODULE SKT FOR 64TQFP
• Eeprom Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

23.3
All of the PIC18F85J90 family devices power their core
digital logic at a nominal 2.5V. For designs that are
required to operate at a higher typical voltage, such as
3.3V, all devices in the PIC18F85J90 family incorporate
an on-chip regulator that allows the device to run its
core logic from V
The regulator is controlled by the ENVREG pin. Tying
V
vides power to the core from the other V
the regulator is enabled, a low-ESR filter capacitor
must be connected to the V
(Figure 23-2). This helps to maintain the stability of the
regulator. The recommended value for the filter capac-
itor is provided in Section 26.3 “DC Characteristics:
PIC18F84J90 Family (Industrial)”.
If ENVREG is tied to V
this case, separate power for the core logic at a nomi-
nal 2.5V must be supplied to the device on the
V
levels, typically 3.3V. Alternatively, the V
and V
nominal voltage. Refer to Figure 23-2 for possible
configurations.
23.3.1
When it is enabled, the on-chip regulator provides a
constant voltage of 2.5V nominal to the digital core
logic. The regulator can provide this level from a V
about 2.5V, all the way up to the device’s V
does not have the capability to boost V
2.5V.
In order to prevent “brown-out” conditions, when the
voltage drops too low for the regulator, the regulator
enters Tracking mode. In Tracking mode, the regulator
output follows V
100 mV.
The on-chip regulator includes a simple Low-Voltage
Detect (LVD) circuit. If V
approximately 2.45V on V
Low-Voltage Detect Interrupt Flag, LVDIF (PIR2<2>),
and clears the REGSLP (WDTCON<7>) bit if it was set.
This can be used to generate an interrupt and put the
application into a low-power operational mode, or trig-
ger an orderly shutdown. Low-Voltage Detection is only
available when the regulator is enabled.
 2010 Microchip Technology Inc.
DD
DDCORE
to the pin enables the regulator, which in turn, pro-
DD
pins can be tied together to operate at a lower
On-Chip Voltage Regulator
/V
CAP
VOLTAGE REGULATION AND
LOW-VOLTAGE DETECTION
pin to run the I/O pins at higher voltage
DD
DD
.
, with a typical voltage drop of
SS
DD
, the regulator is disabled. In
DDCORE
drops too low to maintain
, the circuit sets the
DDCORE
DD
DD
DDCORE
levels below
pins. When
/V
DDMAX
CAP
/V
DD
CAP
pin
. It
of
PIC18F85J90 FAMILY
FIGURE 23-2:
Regulator Enabled (ENVREG tied to V
Regulator Disabled (ENVREG tied to ground):
Regulator Disabled (V
Note 1: These are typical operating voltages. Refer
2.5V
2.5V
C
(1)
to Section 26.1 “DC Characteristics:
Supply Voltage” for the full operating
ranges of V
(1)
F
3.3V
3.3V
(1)
CONNECTIONS FOR THE
ON-CHIP REGULATOR
DD
V
ENVREG
V
V
DD
DD
DDCORE
SS
and V
PIC18F85J90
V
ENVREG
V
V
V
ENVREG
V
V
tied to V
DD
DDCORE
SS
DD
DDCORE
SS
PIC18F85J90
PIC18F85J90
DDCORE
/V
CAP
/V
/V
DDCORE
DS39770C-page 299
CAP
CAP
.
DD
):
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