The SG/GB5-A1EL is a low cost visible light sensor ,with a crrent output which is directly proportional to the light level. Due to the high rejection ration of infrared radiation, the spectral response of the ambient light sensor is close to that of human eyes. The out put current can be converted to a voltage by connecting it in series with a resistor . The dynamic range is determined by the external resistor and power supply (10K and 5V gives a range of 0~200Lux,but can be over 1000 Lux with a 1K resistor). The internal dark current cancellation enables high accuracy over the full temperature range , even at low light levels. It is encapsulated in a plastic package having the same shape as metal packages. The shape of photo IC diode also resembies our 5R type cds sensor(cds photoconductive cells),so photo ic diode can be used as a re placement for those cds sensor .