TSL238T

r r D High-Resolution Conversion of Light Intensity to Frequency With No External Components D High Irradiance Responsivity . . . 3.4 kHz/(mW/cm2) at λp = 640 nm D Low Dark Frequency . . . < 6 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 Lead (Pb) Free Package D RoHS Compliant TSL238T HIGH-SENSITIVITY LIGHT-TO-FREQUENCY CONVERTER TAOS080G − DECEMBER 2007 PACKAGE T 4-LEAD SMD (TOP VIEW) OE 1 4 OUT GND 2 3 VDD Technical coantmesntAsGtill valid Description The TSL238T 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. Output enable (OE) places the output in a high-impedance state for multiple-unit sharing of a microcontroller input line. 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 TSL238T is characterized for operation over the temperature range of −40°C to 85°C and is supplied in a compact 4-lead surface-mount package that is lead (Pb) free and RoHS compliant. Functional Block Diagram Light Photodiode Current-to-Frequency Converter Output...