Datasheet

Table Of Contents
PIC18F87J72 FAMILY
DS39979A-page 446 Preliminary 2010 Microchip Technology Inc.
B.4.5.1 ADC Resolution as a Function of
OSR
The ADC resolution is a function of the OSR
(Section B.4.4 “SINC3 Filter”). The resolution is the
same for both channels. No matter what the resolution
is, the ADC output data is always presented in 24-bit
words, with added zeros at the end, if the OSR is not
large enough to produce 24-bit resolution (left
justification).
TABLE B-6: OSR = 256 OUTPUT CODE EXAMPLES
ADC Output Code (MSB First) Hexadecimal Decimal
011
1 1111 1111 1111 1111 1111 0x7FFFFF + 8,388,607
0111 1111 1111 1111 1111 1110 0x7FFFFE + 8,388,606
0000 0000 0000 0000 0000 0000 0x000000 0
1111 1111 1111 1111 1111 1111 0xFFFFFF -1
1000 0000 0000 0000 0000 0001 0x800001 - 8,388,607
1000 0000 0000 0000 0000 0000 0x800000 - 8,388,608
TABLE B-7: OSR = 128 OUTPUT CODE EXAMPLES
ADC Output Code (MSB First) Hexadecimal
Decimal
23-Bit Resolution
0111 1111 1111 1111 1111 1110 0x7FFFFE + 4,194,303
0111 1111 1111 1110 1111 1100 0x7FFFFC + 4,194,302
0000 0000 0000 0000 0000 0000 0x000000 0
1111 1111 1111 1111 1111 111
0 0xFFFFFE -1
1000 0000 0000 0000 0000 0010 0x800002 - 4,194,303
1000 0000 0000 0000 0000 0000 0x800000 - 4,194,304
TABLE B-8: OSR = 64 OUTPUT CODE EXAMPLES
ADC Output Code (MSB First) Hexadecimal
Decimal
20-Bit resolution
0111 1111 1111 1111 1111
0 0 0 0 0x7FFFF0 + 524, 287
0111 1111 1111 1111 1110 0 0 0 0 0x7FFFE0 + 524, 286
0000 0000 0000 0000 0000 0 0 0 0 0x000000 0
1111 1111 1111 1111 1111
0 0 0 0 0xFFFFF0 -1
1000 0000 0000 0000 0001 0 0 0 0 0x800010 - 524,287
1000 0000 0000 0000 0000 0 0 0 0 0x800000 - 524, 288
TABLE B-9: OSR = 32 OUTPUT CODE EXAMPLES
ADC Output Code (MSB First) Hexadecimal
Decimal
17-Bit resolution
0111 1111 1111 1111 1
0 0 0 0 0 0 0 0x7FFF80 + 65, 535
0111 1111 1111 1111 00 0 0 0 0 0 0 0x7FFF00 + 65, 534
0000 0000 0000 0000 00 0 0 0 0 0 0 0x000000 0
1111 1111 1111 1111 1
0 0 0 0 0 0 0 0xFFFF80 -1
1000 0000 0000 0000 10 0 0 0 0 0 0 0x800080 - 65,535
1000 0000 0000 0000 00 0 0 0 0 0 0 0x800000 - 65, 536