PIC18LF4458T-I/ML Microchip Technology, PIC18LF4458T-I/ML Datasheet - Page 27
![24KB Flash, 2KB RAM, 256 Bytes EEPROM, 35 I/O, USB, 12bit ADC 44 QFN 8x8x0.9mm T](/photos/6/81/68122/150-44-qfn_sml.jpg)
PIC18LF4458T-I/ML
Manufacturer Part Number
PIC18LF4458T-I/ML
Description
24KB Flash, 2KB RAM, 256 Bytes EEPROM, 35 I/O, USB, 12bit ADC 44 QFN 8x8x0.9mm T
Manufacturer
Microchip Technology
Series
PIC® 18Fr
Datasheets
1.PIC18F2221-ISO.pdf
(46 pages)
2.PIC18F2458-ISO.pdf
(46 pages)
3.PIC18F2458-ISO.pdf
(6 pages)
4.PIC18F2458-ISO.pdf
(6 pages)
5.PIC18F2458-ISO.pdf
(6 pages)
Specifications of PIC18LF4458T-I/ML
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
44-QFN
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
2.2
The ADCON2 register allows the user to select an
acquisition time that occurs each time the GO/DONE
bit is set. It also gives users the option to use an
automatically determined acquisition time.
Acquisition time may be set with the ACQT2:ACQT0
bits (ADCON2<5:3>), which provides a range of 2 to
20 T
continues to sample the input for the selected acquisi-
tion time, then automatically begins a conversion.
Since the acquisition time is programmed, there may
be no need to wait for an acquisition time between
selecting a channel and setting the GO/DONE bit.
Manual
ACQT2:ACQT0 = 000. When the GO/DONE bit is set,
sampling is stopped and a conversion begins. The user
is responsible for ensuring the required acquisition time
has passed between selecting the desired input
channel and setting the GO/DONE bit. This option is
also the default Reset state of the ACQT2:ACQT0 bits
and is compatible with devices that do not offer
programmable acquisition times.
In either case, when the conversion is completed, the
GO/DONE bit is cleared, the ADIF flag is set and the
A/D begins sampling the currently selected channel
again. If an acquisition time is programmed, there is
nothing to indicate if the acquisition time has ended or
if the conversion has begun.
TABLE 2-1:
© 2009 Microchip Technology Inc.
Note 1:
AD
. When the GO/DONE bit is set, the A/D module
2:
Selecting and Configuring
Acquisition Time
The RC source has a typical T
For device frequencies above 1 MHz, the device must be in Sleep for the entire conversion or a F
divider should be used instead; otherwise, the A/D accuracy specification may not be met.
acquisition
Operation
16 T
32 T
64 T
2 T
4 T
8 T
T
RC
AD
OSC
OSC
OSC
OSC
OSC
OSC
(1)
vs. DEVICE OPERATING FREQUENCIES
A/D Clock Source (T
is
selected
AD
time of 2.5 μs.
PIC18F2458/2553/4458/4553
AD
when
)
ADCS2:ADCS0
000
100
001
101
010
110
x11
2.3
The A/D conversion time per bit is defined as T
A/D conversion requires 13 T
The source of the A/D conversion clock is software
selectable. There are seven possible options for T
• 2 T
• 4 T
• 8 T
• 16 T
• 32 T
• 64 T
• Internal RC Oscillator
For correct A/D conversions, the A/D conversion clock
(T
minimum
information).
Table 2-1 shows the resultant T
the device operating frequencies and the A/D clock
source selected.
AD
) must be as short as possible, but greater than the
OSC
OSC
OSC
OSC
OSC
OSC
Selecting the A/D Conversion
Clock
T
AD
(see
Assumes T
parameter
Maximum F
1.00 MHz
10.00 MHz
20.00 MHz
40.00 MHz
48.00 MHz
AD
2.50 MHz
5.00 MHz
AD
AD
per 12-bit conversion.
times derived from
Min. = 0.8 μs
DS39887C-page 27
130
(2)
OSC
for
OSC
AD
. The
more
AD
: