“Industry’s easiest-to-use” light-to-digital sensor ICs extend battery life and deliver enhanced functionality
(Technology News, 16 May 2008 )
Intersil Corporation has introduced the industry’s easiest-to-use light-to-digital sensors, designed to increase battery life and deliver enhanced functionality and performance in mobile, computer and consumer electronic products.
The new ISL29010 and ISL29013 are highly accurate sensors that measure and digitize the value of ambient light and then allow access to that information through a standard I2C interface. This provides a simple way to improve efficiency and functionality in end products by enabling applications to automatically adjust to varying light conditions. Performance advantages include extended battery life from keypad and display dimming in mobile devices as well as increased performance in displays for LCD panels, digital picture frames and digital cameras.
The spectral response of these devices attenuates unwanted IR radiation to provide accurate light measurement even in extreme low-light conditions. This is accomplished by integrating a full light-to-digital solution that includes specially tuned photodiodes to remove all unwanted IR noise, a signed 15-bit integrating ADC that allows for low-light sensitivity and automatic noise cancellation.
The ISL29010 and ISL29013 feature gain selection, giving designers the ability to select the dynamic range and low-light sensitivity that best matches the needs of their application. This software-enabled functionality to choose between low-light sensitivity and wider dynamic range ensures maximum performance as well as unmatched flexibility.
The devices operate on 2.5V to 3.3V and require supply current of just 250 microamps, lower than any available light-to-digital sensor ICs. In addition, a power-down mode can be controlled by software via the I2C interface, reducing power consumption to less than 1 microamp.
Both versions incorporate a signed 15-bit ADC to convert small current signals in the presence of AC periodic noise. The ADC provides users with flexible integration or conversion time through either internal or external modes and can reject 50Hz and 60Hz flicker caused by external sources. Users can program the lux range for optimized counts/lux.
As an added feature, the ISL29013 includes an interrupt pin so users can set threshold values to detect specific low or high light thresholds. The ISL29010 includes an address selection pin so two light sensors can be used on the same I2C bus.
