MA180025 Microchip Technology, MA180025 Datasheet - Page 293

• Manufacturer Part Number: MA180025
• Description: MODULE PLUG-IN PIC18F87J90 PIM
• Manufacturer: Microchip Technology
• Series: PIC®r

Specifications of MA180025

• Accessory Type: Plug-In Module (PIM) - PIC18F87J90
• Product: Microcontroller Modules
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC18
• Silicon Core Number: PIC18F
• Silicon Family Name: PIC18FxxJxx
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: PICDEM LCD 2 Demonstration Board (DM163030)
• For Use With: DM163030 - KIT DEV PICDEM LCD2
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

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 inputs.
To determine acquisition time, see Section 21.1 “A/D
Acquisition Requirements”. After this acquisition
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 do an A/D
conversion:
1.
2.
FIGURE 21-2:
 2010 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 the ADIF bit
• Set the ADIE bit
• Set the GIE bit
digital I/O (ADCON1)
Legend: C
V
AIN
R
S
V
I
R
SS
C
R
LEAKAGE
T
PIN
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
V
V
T
T
= 0.6V
= 0.6V
PIC18F87J90 FAMILY
I
±100 nA
LEAKAGE
3.
4.
5.
6.
7.
R
IC
Wait the required acquisition time (if required).
Start conversion:
• Set GO/DONE bit (ADCON0<1>)
Wait for the 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 the ADIF bit, if required.
For the 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
SS
Sampling
Switch
V
DD
AD
R
SS
. A minimum wait of 2 T
Sampling Switch
1
V
SS
C
2
HOLD
3
DS39933D-page 293
= 25 pF
(k)
4
AD
is