Document
Technical coantmesntAsGtill valid
r
r
D High-Resolution Conversion of Light
Intensity to Frequency With No External Components
D High Irradiance Responsivity . . .
2.3 kHz/(mW/cm2) at λp = 524 nm
D Low Dark Frequency . . . < 2 Hz at 505 C D Single-Supply Operation . . . 2.7 V to 5.5 V D Stable 200 ppm/°C Temperature Coefficient D Interfaces Directly to a Microcontroller D RoHS Compliant (−LF Package Only)
TSL237 HIGH-SENSITIVITY LIGHT-TO-FREQUENCY CONVERTER
TAOS052J − SEPTEMBER 2008
PACKAGE S SIDELOOKER (FRONT VIEW)
PACKAGE SM SURFACE MOUNT
SIDELOOKER (FRONT VIEW)
123 GND VDD OUT
123 GND VDD OUT
Description The TSL237 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 TSL237 is characterized for operation over the temperature range of −40°C to 85°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.
For automotive and other extended temperature applications, please contact TAOS for information.
Functional Block Diagram
Light
Photodiode
Current-to-Frequency Converter
Output
Available Options
DEVICE TSL237 TSL237 TSL237
TA −40°C to 70°C −40°C to 70°C −40°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 ORDERING NUMBER S TSL237S S TSL237S−LF SM TSL237SM−LF
The LUMENOLOGY r Company
r
Texas Advanced Optoelectronic Solutions Inc.
1001 Klein Road S Suite 300 S Plano, TX 75074 S (972r) 673-0759 www.taosinc.com
Copyright E 2008, TAOS Inc. 1
TSL237 HIGH-SENSITIVITY LIGHT-TO-FREQUENCY CONVERTER
TAOS052J − SEPTEMBER 2008
Terminal Functions
TERMINAL
NAME
NO.
GND
1
OUT
3
VDD
2
TYPE
DESCRIPTION
Power supply ground (substrate). All voltages are referenced to GND. O Output frequency.
Supply voltage.
Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage, VDD (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 V Operating free-air temperature range, TA (see Note 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −40°C to 85°C Storage temperature range, Tstg (see Note 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −40°C to 85°C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds (S Package) . . . . . . . . . . . . . . . . . . . . 260°C Reflow solder, in accordance with J-STD-020C or J-STD-020D (SM Package) . . . . . . . . . . . . . . . . . . . 260°C
† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and 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-rated conditions for extended periods may affect device reliability.
NOTES: 1. All voltage values are with respect to GND. 2. Long-term storage or operation above 70°C could cause package yellowing that will lower the sensitivity to wavelengths < 500nm.
Technical coantmesntAsGtill valid
Recommended Operating Conditions
Supply voltage, VDD Operating free-air temperature range, TA
MIN NOM 2.7 5 − 40
MAX 5.5 70
UNIT V °C
Electrical Characteristics at VDD = 5 V, TA = 25°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
VOH High-level output voltage VOL Low-level output voltage IDD Supply current
Full-scale frequency‡
IOH = − 1 mA IOL = 1 mA
4 500
Temperature coefficient of responsivity
Wavelength < 600nm, fO = 50 kHz
kSVS Supply-voltage sensitivity
VDD = 5 V ±10%
‡ Full-scale frequency is the maximum operating frequency of the device without saturation.
TYP 4.5
0.25 2
± 200 ± 0.5
MAX
0.4 3
1000
UNIT V V mA
kHz ppm/°C
%/ V
Operating Characteristics at VDD = 5 V, TA = 25°C, λp = 524 nm (unless otherwise noted)
PARAMETER fO Output frequency fD Dark frequency
Re Irradiance responsivity
TEST CONDITIONS Ee = 21.8 μW/cm2 Ee = 0 μW/cm2 Ee = 0 μW/cm2, TA = 50°C
MIN TYP MAX UNIT
40 50 60 kHz
0 0.1
Hz
0 2 Hz
2.3
kHz/(μW/ cm2)
Nonlinearity §
fO = 0 kHz to 10 kHz
± 1%
%F.S.
Step response to full-scale step input
1 pulse of new frequency plus 1 μs
§ Nonlinearity is defined as the deviation of fO from a straight line between zero and full scale, expressed as a percent of full scale.
Copyright E 2008, TAOS Inc. 2
r www.taosinc.com
The LUME.