PIC18F2550-I/SO Microchip Technology, PIC18F2550-I/SO Datasheet - Page 275

• Manufacturer Part Number: PIC18F2550-I/SO
• Description: IC PIC MCU FLASH 16KX16 28SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F2550-I/SO

• Program Memory Type: FLASH
• Program Memory Size: 32KB (16K x 16)
• Package / Case: 28-SOIC (7.5mm Width)
• 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: 24
• Eeprom Size: 256 x 8
• Ram Size: 2K 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
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: SPI/I2C/EAUSART
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 24
• Number Of Timers: 4
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DM163025, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10-ch x 10-bit
• Package: 28SOIC W
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 48 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT28SO-1 - SOCKET TRANSITION 28SOIC 300MILI3-DB18F4550 - BOARD DAUGHTER ICEPIC3DM163025 - PIC DEM FULL SPEED USB DEMO BRD
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

21.6
Figure 21-4 shows the operation of the A/D converter
after the GO/DONE bit has been set and the
ACQT2:ACQT0 bits are cleared. A conversion is
started after the following instruction to allow entry into
Sleep mode before the conversion begins.
Figure 21-5 shows the operation of the A/D converter
after
ACQT2:ACQT0 bits are set to ‘010’ and selecting a
4 T
Clearing the GO/DONE bit during a conversion will
abort the current conversion. The A/D Result register
pair will NOT be updated with the partially completed
A/D
ADRESH:ADRESL registers will continue to contain
the value of the last completed conversion (or the last
value written to the ADRESH:ADRESL registers).
FIGURE 21-4:
FIGURE 21-5:
© 2009 Microchip Technology Inc.
(Holding capacitor continues
acquiring input)
Set GO/DONE bit
AD
1
acquisition time before the conversion starts.
the
T
conversion
CY
Set GO/DONE bit
A/D Conversions
Holding capacitor is disconnected from analog input (typically 100 ns)
T
ACQ
Acquisition
- T
Automatic
2
GO/DONE
Time
AD
Conversion starts
Cycles
T
AD
3
1 T
sample.
A/D CONVERSION T
A/D CONVERSION T
AD
b9
4
bit
2 T
Conversion starts
(Holding capacitor is disconnected)
has
AD
b8
1
This
3 T
been
AD
b9
b7
2
means
4 T
set,
On the following cycle:
ADRESH:ADRESL is loaded, GO/DONE bit is cleared,
ADIF bit is set, holding capacitor is connected to analog input.
PIC18F2455/2550/4455/4550
AD
b8
3
b6
AD
AD
5 T
On the following cycle:
ADRESH:ADRESL is loaded, GO/DONE bit is cleared,
ADIF bit is set, holding capacitor is connected to analog input.
CYCLES (ACQT<2:0> = 000, T
CYCLES (ACQT<2:0> = 010, T
the
the
AD
b5
b7
4
6 T
AD
T
b4
5
b6
AD
7 T
Cycles
After the A/D conversion is completed or aborted, a
2 T
started. After this wait, acquisition on the selected
channel is automatically started.
21.7
The discharge phase is used to initialize the value of
the capacitor array. The array is discharged before
every sample. This feature helps to optimize the
unity-gain amplifier as the circuit always needs to
charge
charge/discharge based on previous measurement
values.
AD
Note:
b3
b5
6
CY
8
wait is required before the next acquisition can be
T
AD
b4
Discharge
b2
7
the
9 T
The GO/DONE bit should NOT be set in
the same instruction that turns on the A/D.
Code should wait at least 2 µs after
enabling the A/D before beginning an
acquisition and conversion cycle.
AD
b3
b1
8
10
capacitor
T
AD
ACQ
b0
b2
9
ACQ
11
= 0)
T
AD
= 4 T
10
b1
Discharge
(Typically 200 ns)
array,
1
AD
DS39632E-page 273
b0
11
)
rather
T
AD
Discharge
(Typically
200 ns)
1
than