L/F Converter Detects Ultra Low Light Levels April 2004 Issue Published Date: April 08, 2004
With a dynamic range of 5,000,000:1, the TSL237 light-to frequency (L/F) converter includes unique low dark-signal circuitry that allows it to detect a typical dark frequency of 0.1 Hz and low-light levels down to 0.00002 lux. The device produces a square-wave output signal, with frequency proportional to light intensity, which directly interfaces to a microcontroller, digital-signal processor, or counter. This square wave promises to eliminate the need for expensive, high-resolution a/d converters and precision amplifiers by providing up to 16 bits of resolution. Target applications include automotive sensors, color calibration, densitometers, laser printers, lighting control, camera exposure control, medical pulse oximetry systems, and others. Available in a 3-pin side looker package, price is $1.67 each/1,000. TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS INC., Plano, TX. (972) 673-0759.
