![background image](/sites/default/files/pdfhtml_microchip/22161A001.png)
R&E International
A Subsidiary of Microchip Technology Inc.
RE46C112
Ionization Smoke Detector IC
Product Specification
© 2009 Microchip Technology Inc. DS22161A-page 1
General Description
The RE46C112 is an ionization type smoke detector IC.
It is intended for applications using ionization type
chambers to detect smoke. When enabled, VOUT is ¼
of either the DETECT input or VDD depending on the
status of the SELECT input. When the Select input is
allowed to float the circuit is in the low current mode
with only the guard amplifier enabled.
Utilizing low power CMOS technology the RE46C112
was designed for use in smoke detectors that comply
with Underwriters Laboratory Specification UL217.
Features
• Guard Outputs for Ion Detector Input
• ± 0.75pA Detect Input Current
• Microprocessor A/D Compatible Analog Output
• Low Quiescent Current Consumption (<10uA)
• Available in 8L PDIP or 8L N SOIC
• 2000V ESD Protection (HBM)
• Available in Standard Packaging or RoHS
Compliant Pb Free Packaging
Pin Configuration
V DD
V CC
SE LE CT
V SS
G 2
DE TE CT
G 1
V O UT
1
8
ABSOLUTE MAXIMUM RATINGS
PARAMETER
SYMBOL VALUE UNITS
Supply Voltage
V
DD
12.5 V
Supply Voltage
V
CC
6 V
Detect Input Voltage Range
V
INDET
V
DD
+.3 V
SELECT Input Voltage Range
V
INSEL
V
CC
+.3 V
Operating Temperature
T
A
-10 to 60
°C
Storage Temperature
T
STG
-55 to 125
°C
Maximum Junction Temperature
T
J
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
![background image](/sites/default/files/pdfhtml_microchip/22161A002.png)
RE46C112
Ionization Smoke Detector IC
R&E International
Product Specification
A Subsidiary of Microchip Technology
Inc.
© 2009 Microchip Technology Inc. DS22161A-page 2
Min
Typ
Max
Units
V
DD
1
Operating
6
12
V
CC
2
Operating
2.7
5.5
V
1
SELECT=open, DETECT=4.5V,
VDD=9V
3
4.5
u
1
SELECT=open, DETECT=6V,
VDD=12V
4
5.5
u
1
SELECT=VCC or VSS,
DETECT=4.5V, VDD=9V
60
90
uA
2
SELECT=open, VCC=5V
DETECT=4.5V, VDD=9V
2.75
4.3
uA
2
SELECT=open, VCC=3V,
DETECT=6V, VDD=12V
1
1.75
u
Input Voltage High
V
ih
3
SELECT
V
CC
-.4
V
Input Voltage Low
V
il
3
SELECT
0.4
V
VDD=12V, DETECT=VDD or
VSS, 0-40% RH
-0.75
0.75
pA
VDD=12V, DETECT=VDD or
VSS, 85% RH, See Note 1
-1.5
1.5
pA
SELECT=VCC or VSS VCC=5V
-15
45
uA
SELECT=VCC or VSS VCC=3V
-4
15
uA
Offset Voltage
VG
OS
6,8
-50
50
mV
Common Mode Voltage
V
CM
7
Guard Amplifier
2
V
DD
-.5
V
Output Impedance
6,8
Guard Amplifier
10
k
5
VDD=6V to 12V,
SELECT=VSS, RL=10K
-2% -
20mV
.25*V
DD
2% +
20mV
V
5
DETECT= 2V to VDD-.5V,
SELECT=VCC, RL=10K
-2% -
20mV
.25*V
DETECT
2% +
20mV
V
Electrical Characteristics at TA = 25°C, VDD=9V, VCC=5V, VSS=0V (unless otherwise noted)
7
Output Voltage
V
out
IL
sel
Input Leakage
IL
det
3
Limits
Supply Voltage
Test Conditions
Supply Current
I
CC
I
DD
Paramete
V
A
A
A
r
Symbol
Test
Pin
Note 1: Sample test only
![background image](/sites/default/files/pdfhtml_microchip/22161A003.png)
RE46C112
Ionization Smoke Detector IC
R&E International
Product Specification
A Subsidiary of Microchip Technology
Inc.
© 2009 Microchip Technology Inc. DS22161A-page 3
PIN DESCRIPTIONS
PIN 1 (VDD) - This pin should be connected to the most positive supply potential, typically a 9 Volt battery. The
VDD voltage can range between 6V and 12V with respect to VSS. Reverse battery protection must be provided
externally.
PIN 2 (VCC) – This positive supply potential can range between 2.7V and 5.5V with respect to VSS and must be
less than the VDD voltage. This pin is usually connected to a microprocessor positive supply voltage.
PIN 3 (SELECT) – This input pin determines the function of VOUT. This pin is typically driven by a
microprocessor port. The input high level should not exceed VCC. If left floating VOUT is inactive and pulled
internally to VSS. If SELECT is at the VIL (low) level then VOUT is nominally ¼ of the VDD voltage. If SELECT is
at the VIH level (high) then VOUT is nominally ¼ of the DETECT voltage.
PIN 4 (VSS) – This pin is the negative supply potential and is usually connected to ground.
PIN 5 (VOUT) – This analog output is a representation of VDD or DETECT or is at VSS depending on the status
of the SELECT input. Typically this output is connected to a microprocessor A to D input to monitor the status of
the supply voltage and the ionization chamber voltage.
PIN 6, 8 (G1, G2) – These pins are connected to the internal guard amplifier output and are within ±50mV of the
DETECT input. These outputs are always active and help to minimize surface leakage to the DETECT pin.
PIN 7 (DETECT) - This input is typically interfaced to an ionization chamber to sense the presence of smoke.
Input leakage is less than ±.75pA on this input.
![background image](/sites/default/files/pdfhtml_microchip/22161A004.png)
RE46C112
Ionization Smoke Detector IC
R&E International
Product Specification
A Subsidiary of Microchip Technology
Inc.
© 2009 Microchip Technology Inc. DS22161A-page 4
Functional Block Diagram
Figure 1
![background image](/sites/default/files/pdfhtml_microchip/22161A005.png)
RE46C112
Ionization Smoke Detector IC
R&E International
Product Specification
A Subsidiary of Microchip Technology
Inc.
© 2009 Microchip Technology Inc. DS22161A-page 5
Typical Application
Figure 2
![background image](/sites/default/files/pdfhtml_microchip/22161A006.png)
RE46C112
Ionization Smoke Detector IC
R&E International
Product Specification
A Subsidiary of Microchip Technology
Inc.
© 2009 Microchip Technology Inc. DS22161A-page 6
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. MICROCHIP
MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY
KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL,
STATUTORY OR OTHERWISE, RELATED TO THE
INFORMATION, INCLUDING BUT NOT LIMITED TO ITS
CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY
OR FITNESS FOR PURPOSE. Microchip disclaims all liability
arising from this information and its use. Use of Microchip devices in
life support and/or safety applications is entirely at the buyer’s risk,
and the buyer agrees to defend, indemnify and hold harmless
Microchip from any and all damages, claims, suits, or expenses
resulting from such use. No licenses are conveyed, implicitly or
otherwise, under any Microchip intellectual property rights.
Trademarks
The Microchip name and logo, the Microchip logo, Accuron,
dsPIC, K
EE
L
OQ
, K
EE
L
OQ
logo,
MPLAB, PIC, PICmicro,
PICSTART, rfPIC, SmartShunt and UNI/O are registered
trademarks of Microchip Technology Incorporated in the U.S.A.
and other countries.
FilterLab, Hampshire, Linear Active Thermistor, MXDEV, MXLAB,
SEEVAL, SmartSensor and The Embedded Control Solutions
Company are registered trademarks of Microchip Technology
Incorporated in the U.S.A.
Analog-for-the-Digital Age, Application Maestro, CodeGuard,
dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN,
ECONOMONITOR, FanSense, In-Circuit Serial Programming,
ICSP, ICEPIC, Mindi, MiWi, MPASM, MPLAB Certified logo,
MPLIB, MPLINK, mTouch, nanoWatt XLP, PICkit, PICDEM,
PICDEM.net, PICtail, PIC
32
logo, PowerCal, PowerInfo,
PowerMate, PowerTool, REAL ICE, rfLAB, Select Mode, Total
Endurance, TSHARC, WiperLock and ZENA are trademarks of
Microchip Technology Incorporated in the U.S.A. and other
countries.
SQTP is a service mark of Microchip Technology Incorporated in
the U.S.A.
All other trademarks mentioned herein are property of their
respective companies.
© 2009, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
Printed on recycled paper.
Microchip received ISO/TS-16949:2002 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in California and
India. The Company’s quality system processes and procedures are for its
PIC
®
MCUs and dsPIC
®
DSCs, K
EE
L
OQ
®
code hopping devices, Serial
EEPROMs, microperipherals, nonvolatile memory and analog products. In
addition, Microchip’s quality system for the design and manufacture of
development systems is ISO 9001:2000 certified.
![background image](/sites/default/files/pdfhtml_microchip/22161A007.png)
RE46C112
Ionization Smoke Detector IC
R&E International
Product Specification
A Subsidiary of Microchip Technology
Inc.
© 2009 Microchip Technology Inc. DS22161A-page 7
![background image](/sites/default/files/pdfhtml_microchip/22161A001.png)
R&E International
A Subsidiary of Microchip Technology Inc.
RE46C112
Ionization Smoke Detector IC
Product Specification
© 2009 Microchip Technology Inc. DS22161A-page 1
General Description
The RE46C112 is an ionization type smoke detector IC.
It is intended for applications using ionization type
chambers to detect smoke. When enabled, VOUT is ¼
of either the DETECT input or VDD depending on the
status of the SELECT input. When the Select input is
allowed to float the circuit is in the low current mode
with only the guard amplifier enabled.
Utilizing low power CMOS technology the RE46C112
was designed for use in smoke detectors that comply
with Underwriters Laboratory Specification UL217.
Features
• Guard Outputs for Ion Detector Input
• ± 0.75pA Detect Input Current
• Microprocessor A/D Compatible Analog Output
• Low Quiescent Current Consumption (<10uA)
• Available in 8L PDIP or 8L N SOIC
• 2000V ESD Protection (HBM)
• Available in Standard Packaging or RoHS
Compliant Pb Free Packaging
Pin Configuration
V DD
V CC
SE LE CT
V SS
G 2
DE TE CT
G 1
V O UT
1
8
ABSOLUTE MAXIMUM RATINGS
PARAMETER
SYMBOL VALUE UNITS
Supply Voltage
V
DD
12.5 V
Supply Voltage
V
CC
6 V
Detect Input Voltage Range
V
INDET
V
DD
+.3 V
SELECT Input Voltage Range
V
INSEL
V
CC
+.3 V
Operating Temperature
T
A
-10 to 60
°C
Storage Temperature
T
STG
-55 to 125
°C
Maximum Junction Temperature
T
J
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
![background image](/sites/default/files/pdfhtml_microchip/22161A002.png)
RE46C112
Ionization Smoke Detector IC
R&E International
Product Specification
A Subsidiary of Microchip Technology
Inc.
© 2009 Microchip Technology Inc. DS22161A-page 2
Min
Typ
Max
Units
V
DD
1
Operating
6
12
V
CC
2
Operating
2.7
5.5
V
1
SELECT=open, DETECT=4.5V,
VDD=9V
3
4.5
u
1
SELECT=open, DETECT=6V,
VDD=12V
4
5.5
u
1
SELECT=VCC or VSS,
DETECT=4.5V, VDD=9V
60
90
uA
2
SELECT=open, VCC=5V
DETECT=4.5V, VDD=9V
2.75
4.3
uA
2
SELECT=open, VCC=3V,
DETECT=6V, VDD=12V
1
1.75
u
Input Voltage High
V
ih
3
SELECT
V
CC
-.4
V
Input Voltage Low
V
il
3
SELECT
0.4
V
VDD=12V, DETECT=VDD or
VSS, 0-40% RH
-0.75
0.75
pA
VDD=12V, DETECT=VDD or
VSS, 85% RH, See Note 1
-1.5
1.5
pA
SELECT=VCC or VSS VCC=5V
-15
45
uA
SELECT=VCC or VSS VCC=3V
-4
15
uA
Offset Voltage
VG
OS
6,8
-50
50
mV
Common Mode Voltage
V
CM
7
Guard Amplifier
2
V
DD
-.5
V
Output Impedance
6,8
Guard Amplifier
10
k
5
VDD=6V to 12V,
SELECT=VSS, RL=10K
-2% -
20mV
.25*V
DD
2% +
20mV
V
5
DETECT= 2V to VDD-.5V,
SELECT=VCC, RL=10K
-2% -
20mV
.25*V
DETECT
2% +
20mV
V
Electrical Characteristics at TA = 25°C, VDD=9V, VCC=5V, VSS=0V (unless otherwise noted)
7
Output Voltage
V
out
IL
sel
Input Leakage
IL
det
3
Limits
Supply Voltage
Test Conditions
Supply Current
I
CC
I
DD
Paramete
V
A
A
A
r
Symbol
Test
Pin
Note 1: Sample test only
![background image](/sites/default/files/pdfhtml_microchip/22161A003.png)
RE46C112
Ionization Smoke Detector IC
R&E International
Product Specification
A Subsidiary of Microchip Technology
Inc.
© 2009 Microchip Technology Inc. DS22161A-page 3
PIN DESCRIPTIONS
PIN 1 (VDD) - This pin should be connected to the most positive supply potential, typically a 9 Volt battery. The
VDD voltage can range between 6V and 12V with respect to VSS. Reverse battery protection must be provided
externally.
PIN 2 (VCC) – This positive supply potential can range between 2.7V and 5.5V with respect to VSS and must be
less than the VDD voltage. This pin is usually connected to a microprocessor positive supply voltage.
PIN 3 (SELECT) – This input pin determines the function of VOUT. This pin is typically driven by a
microprocessor port. The input high level should not exceed VCC. If left floating VOUT is inactive and pulled
internally to VSS. If SELECT is at the VIL (low) level then VOUT is nominally ¼ of the VDD voltage. If SELECT is
at the VIH level (high) then VOUT is nominally ¼ of the DETECT voltage.
PIN 4 (VSS) – This pin is the negative supply potential and is usually connected to ground.
PIN 5 (VOUT) – This analog output is a representation of VDD or DETECT or is at VSS depending on the status
of the SELECT input. Typically this output is connected to a microprocessor A to D input to monitor the status of
the supply voltage and the ionization chamber voltage.
PIN 6, 8 (G1, G2) – These pins are connected to the internal guard amplifier output and are within ±50mV of the
DETECT input. These outputs are always active and help to minimize surface leakage to the DETECT pin.
PIN 7 (DETECT) - This input is typically interfaced to an ionization chamber to sense the presence of smoke.
Input leakage is less than ±.75pA on this input.
![background image](/sites/default/files/pdfhtml_microchip/22161A004.png)
RE46C112
Ionization Smoke Detector IC
R&E International
Product Specification
A Subsidiary of Microchip Technology
Inc.
© 2009 Microchip Technology Inc. DS22161A-page 4
Functional Block Diagram
Figure 1
![background image](/sites/default/files/pdfhtml_microchip/22161A005.png)
RE46C112
Ionization Smoke Detector IC
R&E International
Product Specification
A Subsidiary of Microchip Technology
Inc.
© 2009 Microchip Technology Inc. DS22161A-page 5
Typical Application
Figure 2
![background image](/sites/default/files/pdfhtml_microchip/22161A006.png)
RE46C112
Ionization Smoke Detector IC
R&E International
Product Specification
A Subsidiary of Microchip Technology
Inc.
© 2009 Microchip Technology Inc. DS22161A-page 6
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. MICROCHIP
MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY
KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL,
STATUTORY OR OTHERWISE, RELATED TO THE
INFORMATION, INCLUDING BUT NOT LIMITED TO ITS
CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY
OR FITNESS FOR PURPOSE. Microchip disclaims all liability
arising from this information and its use. Use of Microchip devices in
life support and/or safety applications is entirely at the buyer’s risk,
and the buyer agrees to defend, indemnify and hold harmless
Microchip from any and all damages, claims, suits, or expenses
resulting from such use. No licenses are conveyed, implicitly or
otherwise, under any Microchip intellectual property rights.
Trademarks
The Microchip name and logo, the Microchip logo, Accuron,
dsPIC, K
EE
L
OQ
, K
EE
L
OQ
logo,
MPLAB, PIC, PICmicro,
PICSTART, rfPIC, SmartShunt and UNI/O are registered
trademarks of Microchip Technology Incorporated in the U.S.A.
and other countries.
FilterLab, Hampshire, Linear Active Thermistor, MXDEV, MXLAB,
SEEVAL, SmartSensor and The Embedded Control Solutions
Company are registered trademarks of Microchip Technology
Incorporated in the U.S.A.
Analog-for-the-Digital Age, Application Maestro, CodeGuard,
dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN,
ECONOMONITOR, FanSense, In-Circuit Serial Programming,
ICSP, ICEPIC, Mindi, MiWi, MPASM, MPLAB Certified logo,
MPLIB, MPLINK, mTouch, nanoWatt XLP, PICkit, PICDEM,
PICDEM.net, PICtail, PIC
32
logo, PowerCal, PowerInfo,
PowerMate, PowerTool, REAL ICE, rfLAB, Select Mode, Total
Endurance, TSHARC, WiperLock and ZENA are trademarks of
Microchip Technology Incorporated in the U.S.A. and other
countries.
SQTP is a service mark of Microchip Technology Incorporated in
the U.S.A.
All other trademarks mentioned herein are property of their
respective companies.
© 2009, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
Printed on recycled paper.
Microchip received ISO/TS-16949:2002 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in California and
India. The Company’s quality system processes and procedures are for its
PIC
®
MCUs and dsPIC
®
DSCs, K
EE
L
OQ
®
code hopping devices, Serial
EEPROMs, microperipherals, nonvolatile memory and analog products. In
addition, Microchip’s quality system for the design and manufacture of
development systems is ISO 9001:2000 certified.
![background image](/sites/default/files/pdfhtml_microchip/22161A007.png)
RE46C112
Ionization Smoke Detector IC
R&E International
Product Specification
A Subsidiary of Microchip Technology
Inc.
© 2009 Microchip Technology Inc. DS22161A-page 7