r
r
TSL235R
LIGHT-TO-FREQUENCY CONVERTER
TAOS038E
−SEPTEMBER
2007
D
High-Resolution Conversion of Light
D
Intensity to Frequency With No External
Components
Communicates Directly With a
Microcontroller
Package
Single-Supply Operation Down to 2.7 V
Nonlinearity Error Typically 0.2% at 100 kHz
Stable 150 ppm/°C Temperature Coefficient
Single-Supply Operation
RoHS Compliant (−LF Package Only)
PACKAGE S
SIDELOOKER
(FRONT VIEW)
PACKAGE SM
SURFACE MOUNT
SIDELOOKER
(FRONT VIEW)
D
Compact Three-Leaded Clear-Plastic
D
D
D
D
D
1
GND
2
V
DD
3
OUT
Description
1
GND
2
V
DD
3
OUT
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 320 nm to 700 nm and responds over the light range of 320 nm to 1050 nm.
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.
Functional Block Diagram
Current-to-Frequency
Converter
Light
Photodiode
Output
Available Options
DEVICE
TSL235R
TSL235R
TSL235R
T
A
−25°C
to 70°C
−25°C
to 70°C
−25°C
to 70°C
PACKAGE
−
LEADS
3-lead Sidelooker
3-lead Sidelooker—Lead (Pb) Free
3-lead Surface-Mount Sidelooker—Lead (Pb) Free
PACKAGE DESIGNATOR
S
S
SM
ORDERING NUMBER
TSL235R
TSL235R−LF
TSL235RSM−LF
Terminal Functions
TERMINAL
NAME
GND
OUT
V
DD
NO.
1
3
2
O
TYPE
DESCRIPTION
Power supply ground (substrate). All voltages are referenced to GND.
Output frequency.
Supply voltage.
The
LUMENOLOGY
r
Company
Texas Advanced Optoelectronic Solutions Inc.
1001 Klein Road
S
Suite 300
S
Plano, TX 75074
S
(972) 673-0759
r
www.taosinc.com
1
r
Copyright
E
2007, TAOS Inc.
TAOS [ TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS ]
