In this datasheet the reader can find info about photodiode, ambient light, and ambient light sensor. This datasheet presents information related to light sensor, light, and adc.
Many discussion like photodiode current, interface, and light emitting diode are presented inside this datasheet. Here are grabbed from the datasheet:
The TSL2550 is a digital-output light sensor with a two-wire, SMBus serial interface. It combines two photodiodes and a companding analog-todigital converter (ADC) on a single CMOS integrated circuit to provide light measurements over an effective 12-bit dynamic range with a response similar to that of the human eye. 3 SMBCLK The TSL2550 is designed for use with broad wavelength light sources. One of the photodiodes (channel 0) is sensitive to visible and infrared light, while the second photodiode (channel 1) is sensitive primarily to infrared light. An integrating ADC converts the photodiode currents to channel 0 and channel 1 digital outputs.
Even more, the datasheet gives us more about lumenology, protocol, and sensor.