MC145010

Rev 7.0, 05/2006

Freescale Semiconductor

Technical Data

© Freescale Semiconductor, Inc., 2006. All rights reserved.

Photoelectric Smoke

Detector IC with I/O

The CMOS MC145010 is an advanced smoke detector component containing

sophisticated very-low-power analog and digital circuitry. The IC is used with an

infrared photoelectric chamber. Detection is accomplished by sensing scattered

light from minute smoke particles or other aerosols. When detection occurs, a

pulsating alarm is sounded via on-chip push-pull drivers and an external

piezoelectric transducer.

The variable-gain photo amplifier allows direct interface to IR detectors

(photodiodes). Two external capacitors, C1 and C2, C1 being the larger, determine

the gain settings. Low gain is selected by the IC during most of the standby state.

Medium gain is selected during a local-smoke condition. High gain is used during

push button test. During standby, the special monitor circuit which periodically

checks for degraded chamber sensitivity uses high gain, also.

for common signaling. An on-chip current sink provides noise immunity when the I/

O is an input. A local-smoke condition activates the short-circuit-protected I/O

driver, thereby signaling remote smoke to the interconnected units. Additionally, the

I/O pin can be used to activate escape lights, enable auxiliary or remote alarms,

and/or initiate auto-dialers.

While in standby, the low-supply detection circuitry conducts periodic checks

using a pulsed load current from the LED pin. The trip point is set using two external

resistors. The supply for the MC145010 can be a 9 V battery.

A visible LED flash accompanying a pulsating audible alarm indicates a local-

smoke condition. A pulsating audible alarm with no LED flash indicates a remote-

smoke condition. A beep or chirp occurring virtually simultaneously with an LED

flash indicates a low-supply condition. A beep occurring half-way between LED

flashes indicates degraded chamber sensitivity. A low-supply condition does not

condition and degraded chamber sensitivity can be further distinguished by

performing a push button (chamber) test.

Features

•

Circuit is designed to operate in smoke detector systems that comply with

UL217 and UL268 Specifications

•

Operating Voltage Range: 6 to 12 V

•

Operating Temperature Range: - 10 to 60

°C

•

Average Supply Current: 12

µA

•

Power-On Reset Places IC in Standby Mode (Non-Alarm State)

•

Electrostatic Discharge (ESD) and Latch Up Protection Circuitry on All Pins

•

Chip Complexity: 2000 FETs, 12 NPNs, 16 Resistors, and 10 Capacitors

•

Ideal for battery powered applications.

ORDERING INFORMATION

Device

Temp. Range

Case No.

Package

MC145010P

-55 to +125°C

648-08

16 Lead Plastic Dip

MC145010ED

MC145010DW

751G-04

16 Lead SOICW

MCZ145010EG/EGR2

MC145010

PHOTOELECTRIC SMOKE

DETECTOR IC WITH I/O

P SUFFIX

ED SUFFIX (PB-FREE)

PLASTIC DIP

CASE 648-08

DW SUFFIX

EG SUFFIX (PB-FREE)

SOICW

CASE 751G-04

Figure 1. Pin Connections

C1

C2

Detect

Strobe

IRED

I/O

Brass

Test

Low-Supply

Trip

R1

OSC

LED

Feedback

Silver

1

2

3

4

5

7

6

89

10

11

12

13

14

15

16