PIC18F4220-I/PT Microchip Technology, PIC18F4220-I/PT Datasheet - Page 229

• Manufacturer Part Number: PIC18F4220-I/PT
• Description: IC MCU FLASH 2KX16 A/D 44TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F4220-I/PT

• Core Size: 8-Bit
• Program Memory Size: 4KB (2K x 16)
• Core Processor: PIC
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Type: FLASH
• 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
• Package / Case: 44-TQFP, 44-VQFP
• Controller Family/series: PIC18
• No. Of I/o's: 36
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 512Byte
• Cpu Speed: 40MHz
• No. Of Timers: 4
• Core: PIC
• Processor Series: PIC18F
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 40 MHz
• Data Ram Size: 512 B
• Data Rom Size: 256 B
• On-chip Adc: Yes
• Number Of Programmable I/os: 36
• Number Of Timers: 2 x 8 bit
• Operating Supply Voltage: 2 V to 5.5 V
• Mounting Style: SMD/SMT
• A/d Bit Size: 10 bit
• A/d Channels Available: 13
• Height: 1 mm
• Interface Type: SPI, I2C, USART
• Length: 10 mm
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.2 V
• Width: 10 mm
• 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: Details

21.0
The comparator voltage reference is a 16-tap resistor
ladder network that provides a selectable voltage refer-
ence. The resistor ladder is segmented to provide two
ranges of CV
tion to conserve power when the reference is not being
used. The CVRCON register controls the operation of
the reference as shown in Register 21-1. The block
diagram is given in Figure 21-1.
The comparator reference supply voltage comes from
V
REGISTER 21-1:
© 2007 Microchip Technology Inc.
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7
bit 6
bit 5
bit 4
bit 3-0
Note 1:
DD
CVREN
and V
R/W-0
COMPARATOR VOLTAGE
REFERENCE MODULE
SS
CVROE overrides the TRISA<2> bit setting.
.
REF
CVREN: Comparator Voltage Reference Enable bit
1 = CV
0 = CV
CVROE: Comparator V
1 = CV
0 = CV
CVRR: Comparator V
1 = 0.00 V
0 = 0.25 V
Unimplemented: Read as ‘0’
CVR3:CVR0: Comparator V
When CVRR = 1:
CV
When CVRR = 0:
CV
values and has a power-down func-
CVROE
REF
REF
R/W-0
CVRCON: COMPARATOR VOLTAGE REFERENCE CONTROL REGISTER
= (CVR<3:0>) •
= 1/4 • (CV
REF
REF
REF
REF
(1)
DD
DD
circuit powered on
circuit powered down
voltage level is also output on the RA2/AN2/V
voltage is disconnected from the RA2/AN2/V
to 0.667 V
to 0.75 V
W = Writable bit
‘1’ = Bit is set
R/W-0
CVRR
RSRC
REF
REF
DD
) + (CVR<3:0> + 8) •
DD
V
Range Selection bit
, with V
24
DD
, with V
Output Enable bit
REF
PIC18F2220/2320/4220/4320
Value Selection 0 ≤ VR3:VR0 ≤ 15 bits
DD
U-0
—
DD
/32 step size
/24 step size
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
(1)
R/W-0
CVR3
21.1
The comparator voltage reference can output 16 distinct
voltage levels for each range. The equations used to cal-
culate the output of the comparator voltage reference
are as follows:
EQUATION 21-1:
The settling time of the comparator voltage reference
must be considered when changing the CV
output (see Table 26-2 in Section 26.0 “Electrical
Characteristics”).
V
32
DD
Configuring the Comparator
Voltage Reference
REF
REF
If CVRR = 1:
CV
If CVRR = 0:
CV
-/CV
-/CV
R/W-0
REF
REF
CVR2
REF
= (CVR<3:0>) •
= (CVR<3:0> + 8) •
REF
pin
pin
x = Bit is unknown
R/W-0
CVR1
V
DS39599G-page 227
24
DD
V
32
DD
R/W-0
CVR0
bit 0
REF