PIC18F4321-I/PT Microchip Technology, PIC18F4321-I/PT Datasheet - Page 246

• Manufacturer Part Number: PIC18F4321-I/PT
• Description: IC PIC MCU FLASH 4KX16 44TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F4321-I/PT

• Program Memory Type: FLASH
• Program Memory Size: 8KB (4K x 16)
• Package / Case: 44-TQFP, 44-VQFP
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 36
• Eeprom Size: 256 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 13x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Interface Type: EUSART/I2C/MSSP/SPI
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 36
• Number Of Timers: 4
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 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
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 13-ch x 10-bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT44PT3 - SOCKET TRAN ICE 44MQFP/TQFPAC164305 - MODULE SKT FOR PM3 44TQFP444-1001 - DEMO BOARD FOR PICMICRO MCUAC164020 - MODULE SKT PROMATEII 44TQFP
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F4321 FAMILY
FIGURE 21-1:
21.2
The full range of voltage reference cannot be realized
due to the construction of the module. The transistors
on the top and bottom of the resistor ladder network
(Figure 21-1) keep CV
reference source rails. The voltage reference is derived
from the reference source; therefore, the CV
changes with fluctuations in that source. The tested
absolute accuracy of the voltage reference can be
found in Section 26.0 “Electrical Characteristics”.
21.3
When the device wakes up from Sleep through an
interrupt or a Watchdog Timer time-out, the contents of
the CVRCON register are not affected. To minimize
current consumption in Sleep mode, the voltage
reference should be disabled.
DS39689E-page 244
Voltage Reference Accuracy/Error
Operation During Sleep
CVRR
V
V
CVREN
V
REF
DD
REF
COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
+
-
REF
CVRSS = 0
CVRSS = 1
from approaching the
CVRSS = 1
CVRSS = 0
16 Steps
REF
output
Preliminary
8R
R
R
R
R
R
R
R
21.4
A device Reset disables the voltage reference by
clearing bit, CVREN (CVRCON<7>). This Reset also
disconnects the reference from the RA2 pin by clearing
bit, CVROE (CVRCON<6>) and selects the high-voltage
range by clearing bit, CVRR (CVRCON<5>). The CVR
value select bits are also cleared.
21.5
The voltage reference module operates independently
of the comparator module. The output of the reference
generator may be connected to the RA2 pin if the
CVROE bit is set. Enabling the voltage reference
output onto RA2 when it is configured as a digital input
will increase current consumption. Connecting RA2 as
a digital output with CVRSS enabled will also increase
current consumption.
The RA2 pin can be used as a simple D/A output with
limited drive capability. Due to the limited current drive
capability, a buffer must be used on the voltage
reference output for external connections to V
Figure 21-2 shows an example buffering technique.
8R
Effects of a Reset
Connection Considerations
CVR3:CVR0
© 2007 Microchip Technology Inc.
CV
REF
REF
.