LM3S101 Luminary Micro, Inc., LM3S101 Datasheet - Page 261

• Manufacturer Part Number: LM3S101
• Description: Microcontroller
• Manufacturer: Luminary Micro, Inc.

13
13.1
13.2
October 5, 2006
1.Not all comparators have the option to drive an output pin. See Table 13-1 and Table 13-2 for more
information.
Analog Comparators
An analog comparator is a peripheral that compares two analog voltages, and provides a logical
output that signals the comparison result.
The LM3S101 controller provides two independent integrated analog comparators that can be
configured to drive an output
A comparator can compare a test voltage against any one of these voltages:
The comparator can provide its output to a device pin, acting as a replacement for an analog
comparator on the board, or it can be used to signal the application via interrupts to cause it to
start capturing a sample sequence. The interrupt generation logic is separate.
Block Diagram
Figure 13-1. Analog Comparator Module Block Diagram
Functional Description
Important:
The comparator compares the VIN- and VIN+ inputs to produce an output, VOUT.
An individual external reference voltage
A shared single external reference voltage
A shared internal reference voltage
It is recommended that the Digital-Input enable (the GPIODEN bit in the GPIO
module) for the analog input pin be disabled to prevent excessive current draw from
the I/O pads.
<none>
internal
C0+
C1-
C0-
bus
1
or generate an interrupt.
ACREFCTL
Voltage
Ref
Preliminary
-ve input
+ve input
+ve input (alternate)
reference input
-ve input
+ve input
+ve input (alternate)
reference input
ACSTAT1
ACSTAT0
ACCTL1
ACCTL0
Comparator 1
Comparator 0
interrupt
interrupt
output
output
<none>
interrupt
C0o
interrupt
LM3S101 Data Sheet
261