Texas Instruments Light To Frequency & Light To Voltage
Light to Frequency (LTF) is a method by which the intensity of a light source can be converted into an analog electrical signal. This is done by sensing the light level, producing a pulse that has a frequency proportional to the light level, and using that pulse to drive a frequency-to-voltage (FTV) converter. The FTV converter then outputs an analog voltage that is proportional to the incident light level. This type of conversion is useful for many applications, such as in photocells and photomultipliers, as it allows the output voltage to be used to measure the intensity of the light source. It also makes it possible to measure light intensity over a wide range of intensities, since the output voltage will vary proportionally with the light intensity.