MCP3301T MICROCHIP [Microchip Technology], MCP3301T Datasheet - Page 21

• Manufacturer Part Number: MCP3301T
• Description: 13-Bit Differential Input, Low Power A/D Converter with SPI Serial Interface
• Manufacturer: MICROCHIP [Microchip Technology]

6.0
6.1
The output code format is a binary two’s complement
scheme with a leading sign bit that indicates the sign of
the output. If the IN+ input is higher than the IN- input,
the sign bit will be a zero. If the IN- input is higher, the
sign bit will be a ‘1’.
The diagram shown in
code transfer function. In this diagram, the horizontal
axis is the analog input voltage and the vertical axis is
the output code of the ADC. It shows that when IN+ is
equal to IN-, both the sign bit and the data word are
zero. As IN+ gets larger, with respect to IN-, the sign bit
is a zero and the data word gets larger. The full scale
output code is reached at +4095 when the input [(IN+)
- (IN-)] reaches V
IN+, the two’s complement output codes will be seen
with the sign bit being a one. Some examples of analog
input levels and corresponding output codes are shown
in
TABLE 6-1:
 2011 Microchip Technology Inc.
Full Scale Positive
Full Scale Negative
Table
6-1.
SERIAL COMMUNICATIONS
Output Code Format
REF
BINARY TWO’S COMPLEMENT OUTPUT CODE EXAMPLES.
- 1 LSB. When IN- is larger than
Analog Input Levels
Figure 6-1
(IN+)-(IN-) = V
(IN+)-(IN-) = V
IN+ = (IN-) +2 LSB
IN+ = (IN-) +1 LSB
IN+ = IN-
IN+ = (IN-) - 1 LSB
IN+ = (IN-) - 2 LSB
IN
IN
+
+
- IN
- IN
-
-
= V
= -V
shows the output
REF
REF
REF
REF
+1 LSB
-1 LSB
-2 LSB
Sign
Bit
0
0
0
0
0
1
1
1
1
1111 1111 1111
1111 1111 1110
0000 0000 0010
0000 0000 0001
0000 0000 0000
1111 1111 1111
1111 1111 1110
0000 0000 0001
0000 0000 0000
Binary Data
MCP3301
DS21700D-page 21
Decimal
+4095
+4094
-4095
-4096
DATA
+2
+1
-1
-2
0