TSLM5470, TSLM5550, TSLM5620, TSLM5660, TSLM5880
CHEMICALOPTICAL SENSOR PLATFORM FAMILY
SOES033 – OCTOBER 1997
1
www.taosinc.com
Copyright 2000, TAOS Inc.
Fully Integrated Sensor Includes LED and
Photodetectors
EOC230 Light-to-Frequency Converter
Photodetectors Provide Outstanding
Linearity
Programming Pins Enable Very High
Dynamic Range
Operates Down to 3.3 V
Reference Channel for Ambient Noise
Cancellation
Molded Plastic Lid With Optical Features
Facilitates System Alignment
Excellent for Calorimetric and Absorption
and Refractive Index Measurements
Various LED Wavelengths Available
Description
Each of these chemical-optical sensor platforms consists of two EOC230 light-to-frequency converter detectors
and a single high-efficiency light-emitting diode mounted on a glass/epoxy substrate and encapsulated in an
injection-molded plastic lid with integral optical features.
Light from the LED is projected into waveguides (attached separately) by means of the molded optics in the
center of the sensor lid. Light passing through the waveguides is directed onto the detectors by means of molded
optics at each end of the sensor lid. The light impinging upon the detector surface will be affected by changes
in the chemistry deposited on the sense waveguides. Neither the waveguides nor the chemistry on the sense
waveguides is included with the sensor platform. Two EOC230 light-to-frequency converter detectors are
incorporated to provide a sense channel and a reference channel.
The detector outputs are pulses, the frequencies of which correspond linearly with the amount of light impinging
upon the detector surface. Sensitivity for each detector can be programmed for 1x, 10x, or 100x via logic signals
applied to control pins S0 and S2 as shown in Table 1. Output frequency of each detector can be scaled to divide
by 2, 10, or 100 via logic signals applied to control pins S2 and S3 (Table 1). The TSLM5xxx family of devices
offers light-emitting diodes of various wavelengths to match specific chemistries and applications.
These chemical-optical sensor platforms are well suited for a wide variety of applications, including sensors for
hydrocarbon, carbon monoxide, and oxygen detection, industrial hygiene, home safety, and chemistry
development.
Table 1. Control Pin Functions
S1 S0 SENSITIVITY S3 S2 FOUT SCALING
0 0 Power down 0 0 ÷1
0 1 1x 0 1 ÷2
1 0 10x 1 0 ÷10
1 1 100x 1 1 ÷100
Texas Advanced Optoelectronic Solutions Inc.
800 Jupiter Road, Suite 205 Plano, TX 75074 (972) 673-0759
TSLM5xxx PACKAGE
(TOP VIEW)
20
19
18
17
14
13
12
11
1
2
3
4
7
8
9
10
S2 S
S3 S
S0 S
S1 S
V
DD
S
FOUT S
GND S
LED A
LED C
GND R
FOUT R
V
DD
R
S1 R
S0 R
S3 R
S2 R