Light-to-Frequency (LTF) sensors convert measurements of light intensity to a digital form for direct interfacing to a microcontroller. The output of the device is a square wave or pulse stream the frequency of which is linearly proportional to the light intensity. LTF converters are designed for applications such as ambient light measurement, light absorption/reflection in products such as white goods, photographic equipment, colorimetry, chemical analyzers and display contrast controls. They may be used in any system that requires a wide dynamic range, and/or high resolution digital measurement of light intensity.
| PartNo | Description | Supply Voltage V | Responsivity Hz/µW/cm² | Max. Output Frequency MHz | Selectable Sensitivity and Full-Scale Output Frequency | Output Frequency Tolerances +/- % | Temperature Range °C | Packages | Remark | Datasheet | Demo | Buy | PartNo |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TSL235R | Converter sidelooker package | 2.7-5.5 | 625 @ 635 | 0.5 | 20 | -25 to 70 | S | Not recommended for new design. Please see Ambient Light Sensors device family. | TSL235R | ||||
| TSL237 | Sidelooker package | 2.7-5.5 | 1200 @ 640 | 1 | 20 | -40 to 85 | S, SM | Not recommended for new design. Please see Ambient Light Sensors device family. | TSL237 | ||||
| TSL237T | High-sensitivity converter low profile 4-lead package | 2.7-5.5 | 1200 @ 640 | 1 | 20 | -40 to 85 | T | Not recommended for new design. Please see Ambient Light Sensors device family. | TSL237T | ||||
| TSL238T | High-sensitivity converter low profile 4-pin package | 2.7-5.5 | 3400 @ 640 | 1 | 20 | -40 to 85 | T | Not recommended for new design. Please see Ambient Light Sensors device family. | TSL238T |