ams Datasheet Page 1
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TSL235R
Light-to-Frequency Converter
The TSL235R light-to-frequency converter combines a silicon
photodiode and a current-to-frequency converter on a single
monolithic CMOS integrated circuit. Output is a square wave
(50% duty cycle) with frequency directly proportional to light
intensity (irradiance) on the photodiode. The digital output
allows direct interface to a microcontroller or other logic
circuitry. The device has been temperature compensated for
the ultraviolet-to-visible light range of 320nm to 700nm and
responds over the light range of 320nm to 1050nm. The
TSL235R is characterized for operation over the temperature
range of -25°C to 70°C and is supplied in a 3-lead clear plastic
side-looker package with an integral lens. When supplied in the
lead (Pb) free package, the device is RoHS compliant.
Ordering Information and Content Guide appear at end of
datasheet.
Key Benefits & Features
The benefits and features of the TSL235R Light-to-Frequency
Converter, are listed below:
Figure 1:
Added Value of Using TSL235R
•High-Resolution Conversion of Light Intensity to
Frequency with no External Components
•Communicates Directly with a Microcontroller
•Compact Three-Leaded Clear-Plastic Package
•Single-Supply Operation Down to 2.7V
•Nonlinearity Error Typically 0.2% at 100kHz
•Stable 150ppm/°C Temperature Coefficient
•Single-Supply Operation
Benefits Features
•Detects Light Intensity at a High Resolution •1M:1 Input Dynamic Range
•Provides Low Light Level Operation •Low Dark Frequency of 0.4 Hz (Typ)
•Provides for High Sensitivity to Detect a Small
Change in Light
•High Irradiance Responsivity 0.6kHz/(µW/cm2)
@ λp = 635nm
•Provides Additional Sensitivity Advantages •2x Gain Lens
General Description
ams Datasheet Page 3
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TSL235R − Pin Assignments
The TSL235R pin assignments are described below:
Figure 3:
Pin Diagram of Package S Sidelooker (Front View)
Figure 4:
Terminal Functions
Terminal
Type Description
Name No.
GND 1 Power supply ground (substrate). All voltages are referenced to GND.
VDD 2 Supply voltage
OUT 3 O Output frequency
Pin Assignments
1
GND
2
VDD
3
OUT
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TSL235R − Absolute Maximum Ratings
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. These are stress
ratings only. Functional operation of the device at these or any
other conditions beyond those indicated under Recommended
Operating Conditions is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
Figure 5:
Absolute Maximum Ratings over Operating Free-Air Temperature Range (unless otherwise noted)
Note(s):
1. All voltages are with respect to GND.
Symbol Parameter Min Max Unit
VDD Supply voltage (1) 6V
TAOperating free-air temperature range -25 70 °C
Tstrg Storage temperature range -25 85 °C
Lead temperature 1.6mm (1/16 inch) from case for 10 seconds
(S Package) 260 °C
Absolute Maximum Ratings
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TSL235R − Electrical Characteristics
All limits are guaranteed. The parameters with min and max
values are guaranteed with production tests or SQC (Statistical
Quality Control) methods.
Figure 6:
Recommended Operating Conditions
Figure 7:
Electrical Characteristics at TA = 25°C, VDD = 5V (unless otherwise noted)
Note(s):
1. Full-scale frequency is the maximum operating frequency of the device without saturation.
Figure 8:
Operating Characteristics at VDD = 5V, TA = 25°C
Note(s):
1. Full-scale frequency is the maximum operating frequency of the device without saturation.
2. Nonlinearity is defined as the deviation of fO from a straight line between zero and full scale, expressed as a percent of full scale.
Symbol Parameter Min Typ Max Unit
VDD Supply voltage 2.7 5 5.5 V
TAOperating free-air temperature range -25 70 °C
Symbol Parameter Test Conditions Min Typ Max Unit
VOH High-level output voltage IOH = -4mA 44.5 V
VOL Low-level output voltage IOL = 4mA 0.25 0.4 V
IDD Supply current 2 3 mA
Full-scale frequency (1) 500 kHz
Temperature coefficient of
output frequency Wavelength ≤ 700nm ±150 ppm/°C
kSVS Supply voltage sensitivity VDD = 5V ±10% ±0.5 %/V
Symbol Parameter Test Conditions Min Typ Max Unit
fOOutput frequency
Ee = 430W/cm2,
λp = 635nm 200 250 300 kHz
Ee = 0W/cm20.4 10 Hz
Nonlinearity (2)
fO = 0kHz to 10kHz ±0.1% %F.S.
fO = 0kHz to 100kHz ±0.2% %F.S.
Step response to full-scale
step input
1 pulse of new frequency plus
1s
Electrical Characteristics
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TSL235R − Typical Operating Characteristics
Figure 9:
Output Frequency vs. Irradiance
Figure 10:
Photodiode Spectral Responsivity
Typical Operating
Characteristics
1
0.1
0.01
0.001
0.001 0.01 0.1 1 10
10
100
100 1 k
VDD = 5 V
Op = 635 nm
TA = 25qC
1000
Ee - Irradiance - μW/cm2
fO - Output Frequency (fO − fD) - kHz
300 400 500 600 700 1000800 900 1100
0
0.2
0.4
0.6
0.8
1.0
1.2
λ - Wavelength - nm
Normalized Responsivity
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TSL235R − Typical Operating Characteristics
Figure 11:
Dark Frequency vs. Temperature
Figure 12:
Temperature Coefficient of Output Frequency vs.
Wavelength of Incident Light
VDD = 5 V
Ee = 0
ï25 0 25 50 75
0
0.2
0.4
0.6
0.8
1
1.2
TA -Temperature - °C
fO(dark) - Dark Frequency - Hz
VDD = 5 V
0
1000
2000
3000
4000
5000
6000
7000
300 400 500 600 700 1000800 900
λ - Wavelength of Incident Light- nm
Temperature Coefficient of Output Frequency - ppm/°C
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TSL235R − Application Information
Power-Supply Considerations
Power-supply lines must be decoupled by a 0.01F to 0.1F
capacitor with short leads placed close to the TSL235R
(Figure 14).
Output Interface
The output of the device is designed to drive a standard TTL or
CMOS logic input over short distances. If lines greater than 12
inches are used on the output, a buffer or line driver is
recommended.
Measuring the Frequency
The choice of interface and measurement technique depends
on the desired resolution and data acquisition rate. For
maximum data-acquisition rate, period-measurement
techniques are used.
Period measurement requires the use of a fast reference clock
with available resolution directly related to reference-clock
rate. The technique is employed to measure rapidly varying
light levels or to make a fast measurement of a constant light
source.
Maximum resolution and accuracy may be obtained using
frequency-measurement, pulse-accumulation, or integration
techniques. Frequency measurements provide the added
benefit of averaging out random- or high-frequency variations
(jitter) resulting from noise in the light signal. Resolution is
limited mainly by available counter registers and allowable
measurement time. Frequency measurement is well suited for
slowly varying or constant light levels and for reading average
light levels over short periods of time. Integration, the
accumulation of pulses over a very long period of time, can be
used to measure exposure - the amount of light present in an
area over a given time period.
Application Information
ams Datasheet Page 11
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TSL235R − Packaging Mechanical Data
The device is supplied in a clear plastic three-lead through-hole
sidelooker package (S).
Figure 15:
Package S - Single-In-Line Side-Looker Package Configuration
Note(s):
1. All linear dimensions are in millimeters; tolerance is ±0.25mm unless otherwise stated.
2. Dimension is to center of lens arc, which is located below the package face.
3. The integrated photodiode active area is typically 0.92mm2 in size and is located in the center of the lens and 0.97mm below the
top of the lens surface.
4. Index of refraction of clear plastic is 1.55.
5. Lead finish for TSL235R-LF: solder dipped, 100% Sn.
6. This drawing is subject to change without notice.
Packaging Mechanical Data
The device is supplied in a clear plastic three-lead through-hole sidelooker package (S).
PACKAGE S PLASTIC SINGLE-IN-LINE SIDE-LOOKER PACKAGE
1.642.60
2.30
4.60
R 0.90
1.80
0.42
1
2y 2
0.47 TYP
TOP VIEW
SIDE VIEWFRONT VIEW
0.42
1.56
14.86 + 0.50
4.60
0.15
Note B
Lead Free
Available
Pb
NOTES: A. All linear dimensions are in millimeters; tolerance is r 0.25 mm unless otherwise stated.
B. Dimension is to center of lens arc, which is located below the package face.
C. The integrated photodiode active area is typically 0.92 mm2 in size and is located in the center of the lens and 0.97 mm below the
Green
RoHS
2
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TSL235R − Ordering & Contact Information
Figure 16:
Ordering Information
Buy our products or get free samples online at:
www.ams.com/ICdirect
Technical Support is available at:
www.ams.com/Technical-Support
Provide feedback about this document at:
www.ams.com/Document-Feedback
For further information and requests, e-mail us at:
ams_sales@ams.com
For sales offices, distributors and representatives, please visit:
www.ams.com/contact
Headquarters
ams AG
Tobelbader Strasse 30
8141 Premstaetten
Austria, Europe
Tel: +43 (0) 3136 500 0
Website: www.ams.com
Ordering Code Device TAPackage - Leads Package
Designator
TSL235R-LF TSL235R -25°C to 70°C 3-lead Sidelooker - Lead
(Pb) Free S
Ordering & Contact Information
ams Datasheet Page 13
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TSL235R − RoHS Compliant & ams Green Statement
RoHS: The term RoHS compliant means that ams AG products
fully comply with current RoHS directives. Our semiconductor
products do not contain any chemicals for all 6 substance
categories, including the requirement that lead not exceed
0.1% by weight in homogeneous materials. Where designed to
be soldered at high temperatures, RoHS compliant products are
suitable for use in specified lead-free processes.
ams Green (RoHS compliant and no Sb/Br): ams Green
defines that in addition to RoHS compliance, our products are
free of Bromine (Br) and Antimony (Sb) based flame retardants
(Br or Sb do not exceed 0.1% by weight in homogeneous
material).
Important Information: The information provided in this
statement represents ams AG knowledge and belief as of the
date that it is provided. ams AG bases its knowledge and belief
on information provided by third parties, and makes no
representation or warranty as to the accuracy of such
information. Efforts are underway to better integrate
information from third parties. ams AG has taken and continues
to take reasonable steps to provide representative and accurate
information but may not have conducted destructive testing or
chemical analysis on incoming materials and chemicals. ams AG
and ams AG suppliers consider certain information to be
proprietary, and thus CAS numbers and other limited
information may not be available for release.
RoHS Compliant & ams Green
Statement
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TSL235R − Copyrights & Disclaimer
Copyright ams AG, Tobelbader Strasse 30, 8141 Premstaetten,
Austria-Europe. Trademarks Registered. All rights reserved. The
material herein may not be reproduced, adapted, merged,
translated, stored, or used without the prior written consent of
the copyright owner.
Devices sold by ams AG are covered by the warranty and patent
indemnification provisions appearing in its General Terms of
Trade. ams AG makes no warranty, express, statutory, implied,
or by description regarding the information set forth herein.
ams AG reserves the right to change specifications and prices
at any time and without notice. Therefore, prior to designing
this product into a system, it is necessary to check with ams AG
for current information. This product is intended for use in
commercial applications. Applications requiring extended
temperature range, unusual environmental requirements, or
high reliability applications, such as military, medical
life-support or life-sustaining equipment are specifically not
recommended without additional processing by ams AG for
each application. This product is provided by ams AG “AS IS”
and any express or implied warranties, including, but not
limited to the implied warranties of merchantability and fitness
for a particular purpose are disclaimed.
ams AG shall not be liable to recipient or any third party for any
damages, including but not limited to personal injury, property
damage, loss of profits, loss of use, interruption of business or
indirect, special, incidental or consequential damages, of any
kind, in connection with or arising out of the furnishing,
performance or use of the technical data herein. No obligation
or liability to recipient or any third party shall arise or flow out
of ams AG rendering of technical or other services.
Copyrights & Disclaimer
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TSL235R − Document Status
Document Status Product Status Definition
Product Preview Pre-Development
Information in this datasheet is based on product ideas in
the planning phase of development. All specifications are
design goals without any warranty and are subject to
change without notice
Preliminary Datasheet Pre-Production
Information in this datasheet is based on products in the
design, validation or qualification phase of development.
The performance and parameters shown in this document
are preliminary without any warranty and are subject to
change without notice
Datasheet Production
Information in this datasheet is based on products in
ramp-up to full production or full production which
conform to specifications in accordance with the terms of
ams AG standard warranty as given in the General Terms of
Trade
Datasheet (discontinued) Discontinued
Information in this datasheet is based on products which
conform to specifications in accordance with the terms of
ams AG standard warranty as given in the General Terms of
Trade, but these products have been superseded and
should not be used for new designs
Document Status
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TSL235R − Revision Information
Note(s):
1. Page and figure numbers for the previous version may differ from page and figure numbers in the current revision
2. Correction of typographical errors is not explicitly mentioned.
Changes from 1-00 (2016-Mar-30) to current revision 1-01 (2018-Apr-04) Page
Removed all instances of TSL235RSM and SM package related information
Revision Information
ams Datasheet Page 17
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TSL235R − Content Guide
1 General Description
1 Key Benefits & Features
2 Block Diagram
3 Pin Assignments
4Absolute Maximum Ratings
5 Electrical Characteristics
6 Typical Operating Characteristics
9 Application Information
9 Power-Supply Considerations
9 Output Interface
9 Measuring the Frequency
11 Packaging Mechanical Data
12 Ordering & Contact Information
13 RoHS Compliant & ams Green Statement
14 Copyrights & Disclaimer
15 Document Status
16 Revision Information
Content Guide
