R&E International

A Subsidiary of Microchip Technology Inc.

RE46C140

CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode

Product Specification

2009 © Microchip Technology Inc.

DS22179A-page 1

General Description

The RE46C140 is low power CMOS photoelectric type

smoke detector IC. With minimal external components

this circuit will provide all the required features for a

photoelectric type smoke detector.

The design incorporates a gain selectable photo

amplifier for use with an infrared emitter/detector pair.

An internal oscillator strobes power to the smoke

detection circuitry for 100us every 10 seconds to keep

standby current to a minimum. If smoke is sensed the

detection rate is increased to verify an alarm condition.

A high gain mode is available for push button chamber

testing.

A check for a low battery condition and chamber

integrity is performed every 43 seconds when in

standby. The temporal horn pattern supports the NFPA

72 emergency evacuation signal.

An interconnect pin allows multiple detectors to be

connected such that when one units alarms, all units

will sound.

An internal 10 minute timer can be used for a reduced

sensitivity mode.

Utilizing low power CMOS technology the RE46C140

was designed for use in smoke detectors that comply

with Underwriters Laboratory Specification UL217 and

UL268.

Features

•

Internal Power On Reset

•

Low Quiescent Current Consumption

•

Available in 16L PDIP or 16L N SOIC

•

ESD Protection on all Pins

•

Interconnect up to 40 Detectors

•

10 Minute Timer for Sensitivity Control

•

Temporal Horn Pattern

•

Internal Low Battery and Chamber Test

•

Compatible with Allegro A5366

•

Available in Standard Packaging or RoHS

Compliant Pb Free Packaging.

Pin Configuration

16

TEST

1

C1

2

VSEN

C2

15

VSS

DETECT

3

14

STROBE

4

ROSC

13

ABSOLUTE MAXIMUM RATINGS

PARAMETER

SYMBOL

VALUE

UNITS

Supply Voltage

15

V

Input Voltage Range Except FEED, IO

V

FEED Input Voltage Range

-10 to +22

V

IO Input Voltage Range

-.3 to 17

V

Input Current except FEED

10

mA

Operating Temperature

-25 to 75

°C

Storage Temperature

-55 to 125

°C

Maximum Junction Temperature

150

°C

Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are

stress ratings only and operation at these conditions for extended periods may affect device reliability.

This product utilizes CMOS technology with static protection; however proper ESD prevention procedures should be used when

handling this product. Damage can occur when exposed to extremely high static electrical charge.

5

COSC

12

VDD

IRED

IO

HORNB

LE

6

D

11

7

FEED

10

HORNS

8

9