LM3S2139 Luminary Micro, Inc, LM3S2139 Datasheet - Page 246

• Manufacturer Part Number: LM3S2139
• Description: Lm3s2139 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

Analog-to-Digital Converter (ADC)
11.2.6
11.2.7
246
Figure 11-4. Differential Sampling Range, V
Test Modes
There is a user-available test mode that allows for loopback operation within the digital portion of
the ADC module. This can be useful for debugging software without having to provide actual analog
stimulus. This mode is available through the ADC Test Mode Loopback (ADCTMLB) register (see
page 273).
Internal Temperature Sensor
The internal temperature sensor provides an analog temperature reading as well as a reference
voltage. The voltage at the output terminal SENSO is given by the following equation:
SENSO = 2.7 - ((T + 55) / 75)
This relation is shown in Figure 11-5 on page 246.
Figure 11-5. Internal Temperature Sensor Characteristic
0.75 V
-1.5 V
ADC Conversion Result
0x3FF
0x2FF
0x1FF
- Input Saturation
2.25 V
Preliminary
0.75 V
3.0 V
IN_ODD
= 2.25 V
1.5 V
V
V
IN_EVEN
July 25, 2008