PIC18F6680-I/L Microchip Technology, PIC18F6680-I/L Datasheet - Page 255

• Manufacturer Part Number: PIC18F6680-I/L
• Description: Microcontrollers (MCU) 64KB 3328 RAM 52 I/O
• Manufacturer: Microchip Technology

Specifications of PIC18F6680-I/L

• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 3.25 KB
• Interface Type: I2C/SPI/AUSART/CAN
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 53
• Number Of Timers: 5
• Operating Supply Voltage: 4.2 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, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 12-ch x 10-bit
• Program Memory Type: Flash
• Program Memory Size: 64 KB
• Package / Case: PLCC-68
• Lead Free Status / RoHS Status: 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 con-
version 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.
FIGURE 19-2:
 2004 Microchip Technology Inc.
Legend: C
V
AIN
Rs
V
I
R
SS
C
R
LEAKAGE
PIN
T
IC
HOLD
SS
ANALOG INPUT MODEL
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
PIC18F6585/8585/6680/8680
V
V
T
T
= 0.6V
= 0.6V
I
± 500 nA
LEAKAGE
The following steps should be followed to do an A/D
conversion:
1.
2.
3.
4.
5.
6.
7.
R
IC
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)
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 next acquisition starts.
1k
digital I/O (ADCON1)
V
DD
SS
Sampling
Switch
6V
5V
4V
3V
2V
AD
R
SS
. A minimum wait of 2 T
Sampling Switch
5 6 7 8 9 10 11
V
SS
C
HOLD
= 120 pF
DS30491C-page 253
(k )
AD
is