LM3S1968 Datasheet, PDF (400/709 Pages) List of Unclassifed Manufacturers – Microcontroller

Analog-to-Digital Converter (ADC)
Figure 11-2 on page 400 shows an example of the negative input centered at 1.5 V. In this
configuration, the differential range spans from -1.5 V to 1.5 V. Figure 11-3 on page 400 shows an
example where the negative input is centered at -0.75 V, meaning inputs on the positive input
saturate past a differential voltage of -0.75 V since the input voltage is less than 0 V. Figure
11-4 on page 401 shows an example of the negative input centered at 2.25 V, where inputs on the
positive channel saturate past a differential voltage of 0.75 V since the input voltage would be greater
than 3 V.
Figure 11-2. Differential Sampling Range, V_{IN_ODD} = 1.5 V
ADC Conversion Result
0x3FF
0x1FF
0V
-1.5 V
1.5 V
0V
V_{IN_ODD} = 1.5 V
- Input Saturation
Figure 11-3. Differential Sampling Range, V_{IN_ODD} = 0.75 V
ADC Conversion Result
3.0 V V_{IN_EVEN}
1.5 V DV
0x3FF
-1.5 V
0x1FF
0x0FF
0V
-0.75 V
+0.75 V
- Input Saturation
+2.25 V V_{IN_EVEN}
+1.5 V DV
400
July 15, 2014
Texas Instruments-Production Data