PIC18F2221-I/ML Microchip Technology, PIC18F2221-I/ML Datasheet - Page 233

• Manufacturer Part Number: PIC18F2221-I/ML
• Description: IC PIC MCU FLASH 2KX16 28QFN
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F2221-I/ML

• 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, HLVD, POR, PWM, WDT
• Number Of I /o: 25
• 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 10x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Controller Family/series: PIC18
• No. Of I/o's: 25
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 512Byte
• Cpu Speed: 40MHz
• No. Of Timers: 4
• Package: 28QFN EP
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 40 MHz
• Operating Supply Voltage: 5 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 25
• Interface Type: I2C/SPI/USART
• On-chip Adc: 10-chx10-bit
• Number Of Timers: 4
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT28QFN4 - SOCKET TRANS ICE 28QFN W/CABLEAC164322 - MODULE SOCKET MPLAB PM3 28/44QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

The value in the ADRESH:ADRESL registers is not
modified for a Power-on Reset. The ADRESH:ADRESL
registers will contain unknown data after a Power-on
Reset.
After the A/D module has been configured as desired,
the selected channel must be acquired before the
conversion is started. The analog input channels must
have their corresponding TRIS bits selected as an
input. To determine acquisition time, see Section 19.1
“A/D Acquisition Requirements”. After this acquisi-
tion time has elapsed, the A/D conversion can be
started. An acquisition time can be programmed to
occur between setting the GO/DONE bit and the actual
start of the conversion.
The following steps should be followed to perform an A/D
conversion:
1.
2.
3.
4.
FIGURE 19-3:
© 2007 Microchip Technology Inc.
Configure the A/D module:
• Configure analog pins, voltage reference and
• Select A/D input channel (ADCON0)
• Select A/D acquisition time (ADCON2)
• Select A/D conversion clock (ADCON2)
• Turn on A/D module (ADCON0)
Configure A/D interrupt (if desired):
• Clear ADIF bit
• Set ADIE bit
• Set GIE bit
Wait the required acquisition time (if required).
Start conversion:
• Set GO/DONE bit (ADCON0 register)
digital I/O (ADCON1)
Legend: C
V
AIN
Rs
V
I
R
SS
C
R
LEAKAGE
ANALOG INPUT MODEL
T
PIN
IC
HOLD
SS
ANx
C
5 pF
PIN
= Input Capacitance
= Threshold Voltage
= Leakage Current at the pin due to
= Interconnect Resistance
= Sampling Switch
= Sample/Hold Capacitance (from DAC)
= Sampling Switch Resistance
various junctions
V
DD
V
V
T
T
= 0.6V
Preliminary
= 0.6V
I
±100 nA
5.
6.
7.
FIGURE 19-2:
LEAKAGE
PIC18F4321 FAMILY
R
Wait for A/D conversion to complete, by either:
• Polling for the GO/DONE bit to be cleared
OR
• Waiting for the A/D interrupt
Read A/D Result registers (ADRESH:ADRESL);
clear bit ADIF, if required.
For next conversion, go to step 1 or step 2, as
required. The A/D conversion time per bit is
defined as T
required before the next acquisition starts.
IC
3FFh
3FEh
003h
002h
001h
000h
≤ 1k
V
DD
SS
Sampling
Switch
AD
6V
5V
4V
3V
2V
R
. A minimum wait of 2 T
SS
A/D TRANSFER FUNCTION
Analog Input Voltage
Sampling Switch
1
V
SS
2
C
HOLD
3
DS39689E-page 231
= 25 pF
4
(kΩ)
AD
is