The development of two ambient light sensor LSI models has been announced by ROHM. The BH1600FVC (analog output type) and BH1710FVC (digital output type) feature outstanding spectral sensitivity and are ideally suited for portable electronic devices such as mobile phones and LCD TVs, says the company.
It is possible to improve both the performance
EFFICIENCY and visibility of LCDs (e.g., mobile phones, TVs, notebook PCs) by making brightness adjustments based on the ambient light. Precise control is needed in order to maximize the effects of these improvements. However, the brightness sensitivity range of conventional ambient light sensors differs greatly from that of the human eye. Furthermore, the measurement results of conventional ambient light sensors vary between different light sources, such as sunlight and artificial light, says the company.
The new BH1600FVC and BH1710FVC ambient light sensors, on the other hand, feature spectral sensitivity characteristics similar to the photopic luminous efficiency of the human eye, making it possible to measure a broad range of illumination intensities, from darkness to direct sunlight. In addition, the sensitivity is greatly improved - approximately 10% compared with up to 4 times (400%), depending on the type of light source applied (i.e. fluorescent vs. incandescent light), resulting in stable operation. Moreover, both analog and digital output sensors are available, making them compatible with a wide variety of applications.
The BH1600FVC analog output type ambient light sensor features a two-level output current gain adjustment - an industry first - as well as low voltage operation. The BH1710FVC digital output type incorporates a 16-bit A/D
CONVERTER, is capable of precisely measuring a wide range of intensities in 1-lux increments, and can directly output the illumination intensity digitally - also an industry first - making it possible to eliminate conventionally required external operation processing, says the company.
