Archived by Freescale Semiconductor, Inc., 2009
Freescale Semiconductor
Technical Data
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
• 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
• Pb-Free Packaging Designated by Suffix Code ED
ORDERING INFORMATION
Device
Case No.
MC145018P
MC145018ED
648-08
Package
Plastic Dip
MC145018
Rev. 4.1, 09/2006
MC145018
IONIZATION SMOKE DETECTOR
IC WITH INTERCONNECT AND
TEMPORAL HORN DRIVER
P SUFFIX
ED SUFFIX (PB-FREE)
PLASTIC DIP
CASE 648-08
DETECT
COMP. OUT
I/O
LOW V SET
STROBE
OUT
LED
VDD
TIMING
RESISTOR
FEEDBACK
1
2
3
4
5
6
7
8
16 GUARD HI-Z
15 DETECT INPUT
14 GUARD LO-Z
13 SENSITIVITY SET
12 OSC CAPACITOR
11 SILVER
10 BRASS
9 VSS
Figure 1. Pin Assignment
Freescale Semiconductor, Inc. reserves the right to change the detail specifications, as may be required,
to permit improvements in the design of its products.
© Freescale Semiconductor, Inc., 2007. All rights reserved.
