R&E International
RE46C112
Ionization Smoke Detector IC
Product Specification
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
1
8
G2
DETECT
G1
VO UT
VDD
VCC
SELECT
VSS
ABSOLUTE MAXIMUM RATINGS
PARAMETER
Supply Voltage
Supply Voltage
Detect Input Voltage Range
SELECT Input Voltage Range
Operating Temperature
Storage Temperature
Maximum Junction Temperature
SYMBOL
V
DD
V
CC
V
INDET
V
INSEL
T
A
T
STG
T
J
VALUE
12.5
6
V
DD
+.3
V
CC
+.3
-10 to 60
-55 to 125
150
UNITS
V
V
V
V
°C
°C
°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
Telephone 610.992.0727
Page 1 of 5
E-mail: rande@randeint.com
DS-RE46C112-011207
This datasheet contains PROPRIETARY and CONFIDENTIAL information.
Facsimile 610.992.0734
RE46C112
Ionization Smoke Detector IC
Product Specification
R&E International
Electrical Characteristics at TA = 25°C, VDD=9V, VCC=5V, VSS=0V (unless otherwise noted)
Test
Pin
1
2
1
1
1
I
CC
2
2
Input Voltage High
Input Voltage Low
Input Leakage
V
ih
V
il
IL
det
3
3
7
Parameter
Supply Voltage
Supply Current
Symbol
V
DD
V
CC
I
DD
Test Conditions
Operating
Operating
SELECT=open, DETECT=4.5V,
VDD=9V
SELECT=open, DETECT=6V,
VDD=12V
SELECT=VCC or VSS,
DETECT=4.5V, VDD=9V
SELECT=open, VCC=5V
DETECT=4.5V, VDD=9V
SELECT=open, VCC=3V,
DETECT=6V, VDD=12V
SELECT
SELECT
VDD=12V, DETECT=VDD or
VSS, 0-40% RH
VDD=12V, DETECT=VDD or
VSS, 85% RH, See Note 1
SELECT=VCC or VSS VCC=5V
SELECT=VCC or VSS VCC=3V
Min
6
2.7
Limits
Typ
Max
12
5.5
3
4
60
2.75
1
4.5
5.5
90
4.3
1.75
0.4
Units
V
V
uA
uA
uA
uA
uA
V
V
pA
pA
uA
uA
mV
V
k
V
V
V
CC
-.4
-0.75
-1.5
-15
-4
-50
0.75
1.5
45
15
50
V
DD
-.5
10
2% +
20mV
2% +
20mV
IL
sel
3
Offset Voltage
Common Mode Voltage
Output Impedance
Output Voltage
VG
OS
V
CM
6,8
7
6,8
Guard Amplifier
Guard Amplifier
VDD=6V to 12V,
SELECT=VSS, RL=10K
DETECT= 2V to VDD-.5V,
SELECT=VCC, RL=10K
2
V
out
5
5
-2% -
20mV
-2% -
20mV
.25*V
DD
.25*V
DETECT
Note 1 : Sample test only
Telephone 610.992.0727
Page 2 of 5
E-mail: rande@randeint.com
DS-RE46C112-011207
This datasheet contains PROPRIETARY and CONFIDENTIAL information.
Facsimile 610.992.0734
RE46C112
Ionization Smoke Detector IC
Product Specification
R&E International
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.
Telephone 610.992.0727
Page 3 of 5
E-mail: rande@randeint.com
DS-RE46C112-011207
This datasheet contains PROPRIETARY and CONFIDENTIAL information.
Facsimile 610.992.0734
RE46C112
Ionization Smoke Detector IC
Product Specification
R&E International
Functional Block Diagram
Figure 1
Telephone 610.992.0727
Page 4 of 5
E-mail: rande@randeint.com
DS-RE46C112-011207
This datasheet contains PROPRIETARY and CONFIDENTIAL information.
Facsimile 610.992.0734
RE46C112
Ionization Smoke Detector IC
Product Specification
R&E International
Typical Application
Figure 2
R&E
INTERNATIONAL, Inc.
reserves the right to make changes without further notice to any products herein to improve
reliability, function or design.
R&E
INTERNATIONAL, Inc.
does not assume any liability arising out of the application or use of any product or circuit
described herein; neither does it convey any license under its patent rights, nor the rights of others.
R&E
INTERNATIONAL, Inc.
products are not authorized for use as critical components in life support devices or systems
without the express written approval of the President of
R&E
INTERNATIONAL, Inc.
Life support devices or systems are
devices or systems which are intended for surgical implant into the body to support or sustain life, and whose failure to
perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to
result in a significant injury to the user. A critical component is any component of a life support device or system whose
failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety
or effectiveness.
Telephone 610.992.0727
Page 5 of 5
E-mail: rande@randeint.com
DS-RE46C112-011207
This datasheet contains PROPRIETARY and CONFIDENTIAL information.
Facsimile 610.992.0734