PIC18LF4458-I/P Microchip Technology, PIC18LF4458-I/P Datasheet - Page 25

• Manufacturer Part Number: PIC18LF4458-I/P
• Description: 24KB Flash, 2KB RAM, 256 Bytes EEPROM, 35 I/O, USB, 12bit ADC 40 PDIP .600in TUB
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18LF4458-I/P

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 35
• Program Memory Size: 24KB (12K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 13x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The value in the ADRESH:ADRESL registers is
unknown following Power-on and Brown-out Resets,
and is not affected by any other 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 2.1
“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 2-3:
© 2009 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
ANALOG INPUT MODEL
V
I
R
SS
C
R
LEAKAGE
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
PIC18F2458/2553/4458/4553
DD
V
V
T
T
= 0.6V
= 0.6V
I
±100 nA
5.
6.
7.
FIGURE 2-2:
LEAKAGE
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.
FFEh
FFFh
IC
003h
002h
001h
000h
≤ 1k
V
Sampling
SS
DD
Switch
AD
6V
5V
4V
3V
2V
R
. A minimum wait of 2 T
Analog Input Voltage
SS
A/D TRANSFER FUNCTION
Sampling Switch
1
V
C
SS
2
HOLD
3
= 25 pF
DS39887C-page 25
4
(kΩ)
AD
is