PIC18F8723 Datasheet, PDF (34/60 Pages) Microchip Technology – 64/80-Pin, 1-Mbit,Enhanced Flash Microcontrollers with 12-Bit A/D and nanoWatt Technology

PIC18F8723 FAMILY
The analog reference voltage is software selectable to
either the device’s positive and negative supply voltage
(VDD and VSS), or the voltage level on the RA3/AN3/
VREF+ and RA2/AN2/VREF-/CVREF pins.
The A/D Converter has a unique feature of being able
to operate while the device is in Sleep mode. To oper-
ate in Sleep, the A/D conversion clock must be derived
from the A/D’s internal RC oscillator.
The output of the sample and hold is the input into the
converter, which generates the result via successive
approximation.
A device Reset forces all registers to their Reset state.
This forces the A/D module to be turned off and any
conversion in progress is aborted.
Each port pin associated with the A/D Converter can be
configured as an analog input or a digital I/O. The
ADRESH and ADRESL registers contain the result of
the A/D conversion. When the A/D conversion is com-
plete, the result is loaded into the ADRESH:ADRESL
register pair, the GO/DONE bit (ADCON0<1>) is cleared
and the A/D Interrupt Flag bit, ADIF, is set. The block
diagram of the A/D module is shown in Figure 2-1.
FIGURE 2-1:
A/D BLOCK DIAGRAM
CHS3:CHS0
1111
1110
1101
1100
1011
1010
1001
1000
0111
0110
0101
12-Bit
A/D
Converter
VAIN
(Input Voltage)
0100
0011
0010
VCFG1:VCFG0
0001
Reference
Voltage
VREF+
VREF-
AVDD⁽²⁾
X0
X1
1X
0X
0000
AVSS⁽²⁾
Note 1: Channels AN12 through AN15 are not available on PIC18F6628/6723 devices.
2: I/O pins have diode protection to VDD and VSS.
AN15⁽¹⁾
AN14⁽¹⁾
AN13⁽¹⁾
AN12⁽¹⁾
AN11
AN10
AN9
AN8
AN7
AN6
AN5
AN4
AN3
AN2
AN1
AN0
DS39894A-page 32
Preliminary
© 2007 Microchip Technology Inc.