Datasheet

ManualsBrandsMICROCHIP TECHNOLOGY ManualsLinear ICsLinear-IC

R&E International

A Subsidiary of Microchip Technology Inc.

RE46C140

CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode

Product Specification

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.

2009 © Microchip Technology Inc. DS22179B-page 1

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.

The RE46C140 is recognized by Underwriters

Laboratories for use in smoke detectors that comply

with specification UL217 and UL268.

Features

• Internal Power On Reset

• Low Quiescent Current Consumption

• Available in 16L PDIP, 16L N SOIC or 16L W 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

• UL Recognized per File S24036

• Available in Standard Packaging or RoHS

Compliant Pb Free Packaging.

Pin Configuration

TEST

VSEN C2

VSS

DETECT

STROBE

ROSC

ABSOLUTE MAXIMUM RATINGS

PARAMETER SYMBOL VALUE UNITS

Supply Voltage V

15 V

Input Voltage Range Except FEED, IO V

-.3 to V

+.3 V

FEED Input Voltage Range V

infd

-10 to +22 V

IO Input Voltage Range V

io1

-.3 to 17 V

Input Current except FEED I

10 mA

Operating Temperature T

-25 to 75

°C

Storage Temperature T

STG

-55 to 125

°C

Maximum Junction Temperature T

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.

COSC

VDD

IRED

HORNB

FEED

HORNS

8 9

Summary of content (13 pages)

PAGE 1
R&E International A Subsidiary of Microchip Technology Inc. RE46C140 CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Product Specification General Description Features 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.
PAGE 2
RE46C140 CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Product Specification R&E International A Subsidiary of Microchip Technology Inc.
PAGE 3
RE46C140 CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Product Specification R&E International A Subsidiary of Microchip Technology Inc. DC Electrical Characteristics (continued) at TA= -25° to 75°, VDD=9V, Typical Application (unless otherwise noted) Parameter Output Voltage Low Symbol Test Pin VOL1 8,9 Iol=16mA, VDD=6.5V VOL2 13 Iol=5mA, VDD=6.5V Test Conditions Min 1 .5 VOL3 11 Iol=10mA, VDD=6.5V Output Voltage High VOh1 8,9 Iol=-16mA, VDD=6.5V 5.
PAGE 4
RE46C140 CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Product Specification R&E International A Subsidiary of Microchip Technology Inc. AC Electrical Characteristics at TA =-25° to 75°, VDD=9V, VSS=0V, Component Values from Figure 2 ; R9=100KΩ, R12=10MΩ, C5= 1.5nF(unless otherwise noted) Parameter Symbol Test Pin TPOSC 12 Oscillator Period LED and STROBE On Time Min Limits Typ Max No Alarm Condition 9.4 10.5 11.5 mS Test Conditions Units TON1 11,4 Operating 9.
PAGE 5
RE46C140 CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Product Specification 2009 © Microchip Technology Inc. R&E International A Subsidiary of Microchip Technology Inc.
PAGE 6
RE46C140 CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Product Specification R&E International A Subsidiary of Microchip Technology Inc. Functional Block Diagram Figure 1 2009 © Microchip Technology Inc.
PAGE 7
RE46C140 CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Product Specification R&E International A Subsidiary of Microchip Technology Inc. PIN DESCRIPTIONS PIN# PIN NAME 1 C1 The capacitor connected to this pin sets the photo amplifier gain (high) for the push-to-test and chamber sensitivity test. The size of this capacitor will depend on the chamber background reflections. A=1+(C1/10) where C1 is in pF. The gain should be <10000.
PAGE 8
RE46C140 CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Product Specification R&E International A Subsidiary of Microchip Technology Inc. Typical Application Figure 2 Notes: 1. C3 should be located as close as possible to the device power pins. 2. C3 is typical for an alkaline battery. This capacitance should be increased to 4.7uF or greater for a carbon battery. 3. R10, R11 and C6 are typical values and may be adjusted to maximize sound pressure.
PAGE 9
RE46C140 CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Product Specification R&E International A Subsidiary of Microchip Technology Inc. CIRCUIT DESCRIPTION AND APPLICATION NOTES Note: All timing references are nominal. See electrical characteristics for limits. Standby Internal Timing – With the external components specified in the typical application figure for ROSC and COSC the internal oscillator has a nominal period of 10mS.
PAGE 10
RE46C140 CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Product Specification R&E International A Subsidiary of Microchip Technology Inc. Low Battery and Chamber Test – In standby an internal reference is compared to the voltage divided VDD supply. Low battery status is latched at the conclusion of the LED pulse. The horn will chirp for 10ms every 43 seconds until the low battery condition no longer exists.
PAGE 11
RE46C140 CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Product Specification R&E International A Subsidiary of Microchip Technology Inc. Timing Diagrams Standby, No Alarm (not to Scale) Oscillator TPOSC TPWOSC Internal Clock TON1 TPER1 STROBE TON2 IRED TPLED1 LED Low Supply or Chamber Test Failure LED THON3 Low BatteryTest Low BatteryWarning Chirp Low Battery Warning Chirp Horn THOF3 Chamber Test and Warning is Offset from Low Battery Test and Warning by 21.5 Seconds.
PAGE 12
RE46C140 CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Product Specification R&E International A Subsidiary of Microchip Technology Inc. Timing Diagrams (continued) Local Alarm Timing (not to scale) TPER2 STROBE IRED TPLED2 LED No Alarm Local or Remote Alarm No Alarm Horn Temporal Pattern THON1 THOF1 THOF2 Horn Interconnect Timing TIODLY1 IO as Output TIOFILT TIODLY2 IO as Input Notes: 1. Smoke is not sampled when the horn is active.
PAGE 13
RE46C140 CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Product Specification Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications.