Datasheet

PIC18F97J94 FAMILY
DS30575A-page 486  2012 Microchip Technology Inc.
FIGURE 22-21: 12-BIT A/D TRANSFER FUNCTION
For the 10-bit transfer function (when 10-bit resolution
is available):
• The first code transition occurs when the input
voltage is ((VR+) - (VR-))/1024 or 1.0 LSb.
•The '00 0000 0001' code is centered at VR- +
(1.5 * (((VR+) - (VR-)) / 1024).
•The '10 0000 0000' code is centered at VREFL
+ (512.5 * (((VR+) - (VR-)) /1024).
• An input voltage less than VR- + (((VR-) - (VR-)) /
1024) converts as '00 0000 0000'.
• An input voltage greater than (VR-) + ((1023
(VR+)) - (VR-))/1024) converts as '11 1111
1111'.
0010 0000 0001 (2049)
0010 0000 0010 (2050)
0010 0000 0011 (2051)
0001 1111 1101 (2045)
0001 1111 1110 (2046)
0001 1111 1111 (2047)
1111 1111 1110 (4094)
1111 1111 1111 (4095)
0000 0000 0000 (0)
0000 0000 0001 (1)
Output Code
0010 0000 0000 (2048)
(VINH – VINL)
V
R-
VR+ – VR-
4096
2048 * (VR+ – VR-)
4096
VR+
V
R- +
V
R- +
4095 * (VR + – VR-)
4096
VR- +
0
(Binary (Decimal))
Voltage Level