Datasheet

 2010 Microchip Technology Inc. DS41303G-page 265
PIC18F2XK20/4XK20
19.0 ANALOG-TO-DIGITAL
CONVERTER (ADC) MODULE
The Analog-to-Digital Converter (ADC) allows
conversion of an analog input signal to a 10-bit binary
representation of that signal. This device uses analog
inputs, which are multiplexed into a single sample and
hold circuit. The output of the sample and hold is
connected to the input of the converter. The converter
generates a 10-bit binary result via successive
approximation and stores the conversion result into the
ADC result registers (ADRESL and ADRESH).
The ADC voltage reference is software selectable to
either V
DD or a voltage applied to the external reference
pins.
The ADC can generate an interrupt upon completion of
a conversion. This interrupt can be used to wake-up the
device from Sleep.
Figure 19-1 shows the block diagram of the ADC.
FIGURE 19-1: ADC BLOCK DIAGRAM
AN0
ADC
AN1
AN2
AN4
AVDD
VREF+
ADON
GO/DONE
VCFG0 = 1
VCFG0 = 0
CHS<3:0>
ADRESH ADRESL
10
10
ADFM
VSS
AN5
AN6
AN7
AN3
AN8
AN9
AN10
AN11
AN12
AVSS
VREF-
VCFG1 = 1
VCFG1 = 0
FVR
0000
0001
0010
0011
0100
0101
0111
0110
1000
1001
1010
1011
1100
1101
1110
1111
Unused
Unused
0 = Left Justify
1 = Right Justify