MC14568 Datasheet, PDF (1/11 Pages) Freescale Semiconductor, Inc – Low-Power CMOS Ionization Smoke Detector with Interconnect and Timer

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Low-Power CMOS Ionization Smoke
Detector with Interconnect and Timer
The MC14568, 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.
An internal oscillator with associated logic controls the overall functionality by
powering down the device for 1.67 seconds and sensing smoke in a 10 ms
window. In this way, standby current consumption is reduced to between 5.0 and
9.0 µA, thus providing longer battery life. In addition, a networking capability
allows as many as 125 to be interconnected so that if any unit senses smoke, all
units will sound an alarm.
The MC14568 is supplied in a 16-pin dual in-line plastic package and is
designed to run on a power supply between 6 to 12 Volts.
Features
• Speed-Up Sampling Rate of 40 ms of Internal Clock Period (Pin 12) After First
Detection of Smoke
• Timer Function for Reduced Sensitivity for a Nominal Period of 6.43 Minutes
(10 Minutes Max)
• High-Smoke Detection in the “Reduced Sensitivity” Mode
• Internal and External Low Battery Threshold
• Internal and External Smoke Reference Settings
• Guaranteed Power Up Without Random LED and Horn Chirps
• Reversed Battery Protection
• Low Leakage Detect Pin
• Metal Option to Add Double Chirp at End of Reduced Sensitivity Period;
Default is No Chirp
• Pb-Free Packaging Designated by Suffix Code ED
Device
PC14568P/R2
PC14568ED/R2
ORDERING INFORMATION
Case No.
648-08
Package
Plastic Dip
Document Number: MC14568
Rev. 1.0, 11/2006
MC14568
LOW-POWER CMOS IONIZATION
SMOKE DETECTOR WITH
INTERCONNECT AND TIMER
P SUFFIX
ED SUFFIX (PB-FREE)
PLASTIC DIP
CASE 648-08
TIMER START 1
I/O 2
LOW-V SET 3
TIMER OUT 4
LED 5
VDD 6
TIMING R 7
FEEDBACK ⁸
16 GUARD 2
15 DETECT INPUT
14 GUARD 1
13 SENSITIVITY SET
12 OSCILLATOR CAP
11 HORN 2
10 HORN 1
9 VSS
Figure 1. Pin Connections
This document contains certain information on a new product.
Specifications and information herein are subject to change without notice.
© Freescale Semiconductor, Inc., 2006. All rights reserved.