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Motorola Sensor Device Data
www.motorola.com/semiconductors
Go to: www.freescale.com
Prepared by: Leticia Gomez and Diana Pelletier
Sensor Applications Engineering
Motorola Semiconductor Products Sector
Phoenix, Arizona
INTRODUCTION
The MC14600, an IC designed for alarm applications, is a
versatile part that can easily be configured with a minimum
number of external components to serve a wide range of alarm
applications and circuit configurations. For example, the
MC14600 can be used in systems that detect pressure and
temperature change, liquid levels, motion or intrusion. This
application note presents considerations in interfacing exter-
nal components to the MC14600 and an approach for config-
uring it with a latch.
The MC14600 Alarm IC can be simply described as a
comparator that determines whether an alarm condition exists
and in response drives a piezo horn. As illustrated in Figure 1
the MC14600 is more than a comparator and a horn driver. It
drives an LED to indicate the device is working and has inter-
nal low battery detection circuitry. In the event of a low battery
the MC14600 provides the signal to chirp the piezo horn. It
also has a logical output that can be used to drive other out-
puts such as an LED. The MC14600 alarm threshold and
oscillator speed are set externally providing system design
flexibility. Figure 2 is a detailed block diagram of the MC14600
that includes the pin numbers referenced in this document.
Figure 1. Alarm IC Concept
INPUT
+
–
ALARMTHRESHOLD
LOW BATTERY
DETECTION
LOGICAL OUTPUT
PIEZO HORN
LED
Figure 2. MC14600 Block Diagram
11
10
8
HORN FEEDBACK
HORN
OUT 2
HORN
OUT 1
ALARM
LOGIC
OSC
AND
TIMING
5
LED
VDD = PIN 6
VSS = PIN 9
Rbias
7
VDD
+
–
LOW BATTERY
COMPARATOR
VDD
LOW V COMP.
OUT
4
VDD
3
LOW V SET
1
DETECT
COMPARATOR OUT
+
–
13
DETECT
COMPARATOR
ALARM
THRESHOLD
15
ALARMDETECT
INPUT
+
–
VDD
HI–Z
16
GUARD
AMP
12
Cosc
SEMICONDUCTOR APPLICATION NOTE
REV 3
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Freescale Semiconductor, Inc.
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