Ionization Smoke Detector IC

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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

-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

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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

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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. 
 

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/22161A-html.html
background image

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 

 
 
 

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background image

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 

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background image

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. 

 
 

 

 

 

 

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background image

RE46C112 

                          

  

Ionization Smoke Detector IC 

                                                   R&E International 

Product Specification                                                                                              

A Subsidiary of Microchip Technology

 

Inc.

  

© 2009 Microchip Technology Inc.                                                                                                                    DS22161A-page 7 
      

                                                                                                                                      

 

 

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/22161A-html.html
background image

 

              

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

-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

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/22161A-html.html
background image

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

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/22161A-html.html
background image

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. 
 

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/22161A-html.html
background image

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 

 
 
 

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background image

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 

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/22161A-html.html
background image

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. 

 
 

 

 

 

 

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/22161A-html.html
background image

RE46C112 

                          

  

Ionization Smoke Detector IC 

                                                   R&E International 

Product Specification                                                                                              

A Subsidiary of Microchip Technology

 

Inc.

  

© 2009 Microchip Technology Inc.                                                                                                                    DS22161A-page 7 
      

                                                                                                                                      

 

 

Maker
Microchip Technology Inc.