LM3S101_0610 Datasheet, PDF (261/300 Pages) List of Unclassifed Manufacturers – Microcontroller

LM3S101 Data Sheet
13
13.1
13.2
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 output¹ or generate an interrupt.
A comparator can compare a test voltage against any one of these voltages:
„ An individual external reference voltage
„ A shared single external reference voltage
„ A shared internal reference voltage
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
C1-
<none>
-ve input _{Comparator 1}
+ve input
output
+ve input (alternate)
ACCTL1
ACSTAT1
interrupt
reference input
<none>
interrupt
C0-
-ve input _{Comparator 0}
C0+
+ve input
output
C0o
+ve input (alternate)
ACCTL0
ACSTAT0
interrupt
reference input
interrupt
internal
bus
Voltage
Ref
ACREFCTL
Functional Description
Important: 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.
The comparator compares the VIN- and VIN+ inputs to produce an output, VOUT.
1.Not all comparators have the option to drive an output pin. See Table 13-1 and Table 13-2 for more
information.
October 5, 2006
261
Preliminary