Freescale Semiconductor
Technical Data
MC145018
Rev 4, 05/2005
Low-Power CMOS
Ionization Smoke Detector IC with
Interconnect and Temporal
Horn Driver
The MC145018, when used with an ionization chamber and a small number
of external components, will detect smoke. When smoke is sensed, an alarm is
sounded via an external piezoelectric transducer and internal drivers. This circuit
is designed to operate in smoke detector systems that comply with UL217 and
UL268 specifications.
Features
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Ionization Type with On-Chip FET Input Comparator
Piezoelectric Horn Driver
Guard Outputs on Both Sides of Detect Input
Input-Protection Diodes on the Detect Input
Low-Battery Trip Point, Internally Set, can be Altered Via External Resistor
Detect Threshold, Internally Set, can be Altered Via External Resistor
Pulse Testing for Low Battery Uses LED for Battery Loading
Comparator Output for Detect
Internal Reverse Battery Protection
Strobe Output for External Trim Resistors
I/O Pin Allows Up to 40 Units to be Connected for Common Signaling
Supports NFPA 72, ANSi 53.41, and ISO 8201
Audible Emergency Evacuation Signals
Power-On Reset Places IC in Standby Mode
MC145018
IONIZATION SMOKE DETECTOR
IC WITH INTERCONNECT AND
TEMPORAL HORN DRIVER
P SUFFIX
PLASTIC DIP
CASE 648-08
Detect
Comp. Out
I/O
Low V Set
Strobe Out
LED
V
DD
Timing
Resistor
Feedback
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
Guard Hi-z
Detect Input
Guard Lo-Z
Sensitivity Set
OSC Capacitor
Silver
Brass
V
SS
ORDERING INFORMATION
Device
MC145018P
Case No.
648-08
Package
Plastic Dip
Figure 1. Pin Assignment
© Freescale Semiconductor, Inc., 2005. All rights reserved.
FREESCALE [ FREESCALE SEMICONDUCTOR, INC ]
