RE46C144
CMOS Photoelectric Smoke Detector ASIC with Interconnect
and Timer Mode
Features
•
•
•
•
•
•
•
•
•
Internal Power-On Reset
Low Quiescent Current Consumption
ESD Protection on all Pins
Interconnect up to 40 Detectors
10 Minute Timer for Sensitivity Control
75% Duty Cycle Horn Pattern
Internal Low Battery and Chamber Test
Compatible with Allegro A5358
UL Recognized per File S24036
General Description
The RE46C144 is a 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 100 µs 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 alarm horn pattern utilizes a 75% duty
cycle.
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 RE46C144 device is recognized by
Underwriters Laboratories for use in smoke
detectors that comply with specification UL217 and
UL268.
Package Types
RE46C144
PDIP, SOIC, SOICN
C1
C2
DETECT
STROBE
V
DD
IRED
IO
HORNB
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
TEST
VSEN
V
SS
ROSC
COSC
LED
FEED
HORNS
2009-2012 Microchip Technology Inc.
DS22180C-page 1
RE46C144
Functional Block Diagram
VDD (5)
Low Battery
+
-
+
-
Smoke Comparator
IO (7)
Horn Driver
FEED (10)
HS (9)
Logic and
Timing
VSEN (15)
HB (8)
LED (11)
V
DD
-3.5V
PHOTOAMP
DETECT (3)
C1 (1)
+
-
Bias and
Power Reset
IRED (6)
C2 (2)
Oscillator
V
DD
-5V
ROSC (13)
COSC (12)
STROBE (4)
TEST (16)
VSS (14)
Typical Application
9v
Battery
C3
1 µF
R
ADJ1
R2
5k
R3
8.2k
C1
.047 µF
C2
4700 pF
Push-to-Test
1
R4
16
15
14
R9
R12
10M
C5
1.5nF
D3
2
560
R
ADJ2
R1
4.7k
D6
R5
250k
3
4
5
13
100k
12
11
10
9
C6
1.0nF
R10
1.5M
R11
220k
R13
330
R6
1k
D5
C4
100 µF
R7
22
Q3
6
7
8
Smoke Chamber
To Other Units
R8
330
Note 1:
2:
3:
C3 should be located as close as possible to the device power pins.
C3 is typical for an alkaline battery. This capacitance should be increased to 4.7 µF or greater for a carbon battery.
R10, R11 and C6 are typical values and may be adjusted to maximize sound pressure.
DS22180C-page 2
2009-2012 Microchip Technology Inc.
RE46C144
1.0
1.1
ELECTRICAL
CHARACTERISTICS
Absolute Maximum Ratings†
V
DD
....................................................................................15V
Input Voltage Range Except FEED, IO .......... V
IN
= -.3V to V
DD
+.3V
FEED Input Voltage Range ..................... V
INFD
=-10 to +22V
IO Input Voltage Range................................. V
IO1
= -.3 to 15V
Input Current except FEED ................................... I
IN
= 10 mA
Operating Temperature ................................T
A =
-25 to +75°C
Storage Temperature ............................T
STG
= -55 to +125°C
Maximum Junction Temperature ......................... T
J
= +150°C
† Notice:
Stresses above those listed under “Maximum
ratings” may cause permanent damage to the device.
This is a stress rating only and functional operation of
the device at these or any other conditions above those
indicated in the operation listings of this specification is
not implied. Exposure to maximum rating conditions for
extended periods may affect device reliability.
DC ELECTRICAL CHARACTERISTICS
DC Electrical Characteristics:
Unless otherwise indicated, all parameters apply at T
A
= -25°C to +75°C, V
DD
= 9V.
Parameter
Supply Voltage
Supply Current
Symbol
V
DD
I
DD1
I
DD2
Test Pin
5
5
5
Min.
6
—
—
Typ.
—
4
5.5
Max.
12
6
8
Units
V
µA
µA
Conditions
Operating
Configured as in
Typical
Application,
COSC=V
SS
Configured as in
Typical
Application,
V
DD
= 12V,
COSC = V
SS
Configured as in
Typical
Application,
STROBE on,
IRED off, V
DD
= 12V
Configured as in
Typical
Application,
STROBE on,
IRED on, V
DD
= 12V,
Note 1
FEED
No Local Alarm, IO as
input
V
SEN
TEST
FEED
No Local Alarm, IO as
Input
VSEN
TEST
V
DD
= 12V, COSC = 12V,
STROBE active
V
DD
= 12V, V
IN
= V
SS
V
DD
= 12V, V
IN
= V
SS
FEED = -10V
I
DD3
5
—
—
2
mA
I
DD4
5
—
—
3
mA
Input Voltage High
V
IH1
V
IH2
V
IH3
V
IH4
10
7
15
16
10
7
15
16
1, 2, 3
10, 12
15, 16
10
6.2
3.2
1.6
8.5
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
2.7
1.5
.5
7
-100
-100
-1
-50
V
V
V
V
V
V
V
V
nA
nA
µA
µA
Input Voltage Low
V
IL1
V
IL2
V
IL3
V
IL4
Input Leakage Low
I
IL1
I
IL2
I
IL3
I
IFD
Note 1:
2:
3:
4:
Does not include Q3 emitter current.
Not production tested.
Typical values are for design information and are not ensured.
Limits over the specified temperature range are not production tested and are based on characterization
data.
2009-2012 Microchip Technology Inc.
DS22180C-page 3
RE46C144
DC ELECTRICAL CHARACTERISTICS (CONTINUED)
DC Electrical Characteristics:
Unless otherwise indicated, all parameters apply at T
A
= -25°C to +75°C, V
DD
= 9V.
Parameter
Input Leakage High
Symbol
I
IH1
I
IH2
I
HFD
Input Pull Down
Current
I
PD1
I
PD2
I
PDIO1
I
PDIO2
Output Leakage
Current Low
Output Leakage
Current High
Output Voltage Low
I
OZL1
I
OZH1
V
OL1
V
OL2
V
OL3
Output Voltage High
Output Current
V
OH1
I
IOH1
I
IODMP
Low Battery
Alarm Voltage
Output Voltage
V
LB
V
STOF
V
STON
V
IREDOF
V
IREDON
Test Pin
1, 2
3, 10, 12
10
16
15
7
7
11, 13
11, 13
8, 9
13
11
8, 9
7
7
5
4
4
6
6
Min.
—
—
—
.25
.1
20
—
—
—
—
—
—
5.5
-4
5
6.9
V
DD
– .1
Typ.
—
—
—
—
.25
—
—
—
—
—
.5
—
—
—
—
7.2
—
-16
—
7.5
—
Max.
100
100
50
10
.5
80
140
-1
1
1
—
.6
Units
nA
nA
µA
µA
µA
µA
µA
µA
µA
V
V
V
V
mA
mA
V
V
V
V
V
STROBE off, V
DD
=12V,
I
OUT
= -1 µA
STROBE on, V
DD
= 9V,
I
OUT
= 100 µA to 500 µA
IRED off, V
DD
= 12V,
I
OUT
= 1 µA
IRED on, V
DD
= 9V
I
OUT
= 0 to -6 mA,
T
A
= +25°C
Local smoke,
Push-to-Test or Chamber
Test,
Note 2
Internal Reference
Conditions
V
DD
= 12V, V
IN
= V
DD
,
STROBE active
V
DD
= 12V, V
IN
= V
DD
FEED = 22V
V
IN
= V
DD
V
IN
= V
DD
V
IN
= V
DD
V
IN
= 15V, V
DD
= 12V
Output Off, Output = V
SS
Output Off, Output = V
DD
Iol = 16 mA, V
DD
= 6.5V
Iol = 5 mA, V
DD
= 6.5V
Iol = 10 mA, V
DD
= 6.5V
Iol = -16 mA, V
DD
= 6.5V
Alarm,
V
IO
= V
DD
- 2V or V
IO
= 0V
At Conclusion of Local
Alarm or Test, V
IO
= 1V
V
DD
– 5.25 V
DD
– 5 V
DD
- 4.75
—
2.85
—
3.1
.1
3.35
Common Mode
Voltage
Smoke Compare
Reference
Temperature
Coefficient
V
CM1
1, 2, 3
.5
—
V
DD
– 2
V
V
REF
T
CST
T
CIRED
—
4
6
4, 5
6, 5
V
DD
– 3.7
—
—
—
—
—
.01
.3
-50
-30
V
DD
– 3.3
—
—
—
—
V
%/ºC V
DD
= 6V to 12V,
STROBE Output Voltage
%/ºC V
DD
= 6V to 12V,
IRED Output Voltage
dB
dB
Active, V
DD
= 6V to 12V
Active, V
DD
= 6V to 12V
Line Regulation
Note 1:
2:
3:
4:
∆V
STON
∆V
IREDON
Does not include Q3 emitter current.
Not production tested.
Typical values are for design information and are not ensured.
Limits over the specified temperature range are not production tested and are based on characterization
data.
DS22180C-page 4
2009-2012 Microchip Technology Inc.
RE46C144
TABLE 1-1:
AC ELECTRICAL CHARACTERISTICS
AC Electrical Characteristics:
Unless otherwise indicated, all parameters apply at T
A
= -25°C to +75°C, V
DD
= 9V,
V
SS
= 0V, Component Values from
Typical Application;
R
9
= 100 K, R
12
= 10 M, C
5
= 1.5 nF.
Parameter
Oscillator Period
LED and
STROBE On Time
LED Period
Symbol
T
POSC
T
ON1
T
PLED1
T
PLED2
T
PLED3
T
PLED4
STROBE and IRED
Pulse Period
T
PER1
T
PER1A
T
PER1B
T
PER2
T
PER3
T
PER4
T
PER5
IRED On Time
Horn On Time
T
ON2
T
HON1
T
HON2
Horn Off Time
T
HOF1
T
HOF3
IO Charge Dump
Duration
IO Delay
IO Filter
T
IODMP
T
IODLY1
T
IOFILT
Test
Pin
12
11, 4
11
11
11
11
4, 6
4, 6
4, 6
4, 6
4, 6
4, 6
4, 6
6
8, 9
8, 9
8, 9
8, 9
7
7
7
9.6
2.42
1.21
1.21
9.7
300
39
94
227
9.5
76
39
.91
0
600
104
252
10.5
84
43
Min
9.4
9.4
39
.6
9.6
Typ
10.5
10.5
43
.67
10.75
LED IS NOT ON
10.75
2.7
1.33
1.33
10.5
336
11.8
2.96
1.47
1.47
11.8
370
47
115
277
11.5
92
47
1.46
Max
11.5
11.5
47
.74
11.8
Units
ms
ms
s
s
s
s
s
s
s
s
s
ms
s
µs
ms
ms
ms
s
s
s
ms
Conditions
No alarm condition
Operating
Standby, no alarm
Local alarm condition
Timer mode, no local alarm
Remote alarm only
Standby, no alarm
Standby, after one valid smoke
sample
Standby, after two consecutive
valid smoke samples
In Local Alarm (three consecu-
tive valid smoke samples)
In Remote Alarm
Push-button Test
Chamber Test or Low-battery
Test, no alarms
Operating
Operating, alarm condition,
Note 1
Low Battery or Failed Chamber
Test, no alarm
Operating, Alarm Condition,
Note 1
Low Battery or Failed Chamber
Test, no alarm
At conclusion of local alarm or
test
From start of local alarm to IO
Active
IO pulse-width ensured to be
filtered. IO as input, no local
alarm
No local alarm, from IO Active
to Horn Active
No alarm condition,
Note 2
Remote Alarm Delay
Timer Period
Note 1:
2:
3:
4:
5:
T
IODLY2
T
TPER
7
.75
7
8.5
1.65
10
s
Min
See timing diagram for Horn Temporal Pattern
During the Timer mode, the LED period is 10.5 seconds. The LED period will return to 43 seconds at the
conclusion of the Timer mode.
T
POSC
and T
ON2
are 100% production tested. All other timing is guaranteed by functional testing.
Typical values are for design information and are not ensured.
Limits over the specified temperature range are not production tested and are based on characterization
data.
2009-2012 Microchip Technology Inc.
DS22180C-page 5
嵌入式系统
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
