MAX44007/MAX44009: Maxim's digital ambient light sensor that reduces power consumption by more than 100 times

* MAX44007/MAX44009 is a digital ambient light sensor that combines two light sensors, an ADC, digital functions, and an I2C interface in an ultra-small 2mm x 2mm x 0.6mm package.
These ICs extend battery life by consuming 100 times less power than the nearest competing products.
The interrupt function continuously measures ambient light and reports it to the microcontroller when it exceeds a threshold. This feature further reduces power consumption by decreasing the frequency of I2C communication.
These ICs are suitable for tablet PCs, smartphones, laptops, TVs, digital lighting management systems, and light intensity monitoring applications.

Maxim's digital ambient light sensor that reduces power consumption by more than 100 times

Maxim's 2nd Generation Digital Ambient Light Sensor that Maximizes Battery Life and Simplifies System Design

Maxim Integrated Products (NASDAQ: MXIM) has launched the MAX44007/MAX44009 digital ambient light sensor (ALS) ICs, which feature an integrated proprietary adaptive gain block. Designed with Maxim's proprietary BiCMOS technology, these ICs integrate two light sensors, an ADC, and digital functions into an ultra-small 2mm x 2mm x 0.6mm package. This integration delivers industry-leading performance while saving valuable board space.

The MAX44007/MAX44009 consumes 100 times less power than the nearest competitor, significantly extending battery life. In addition, these devices provide a unique interrupt function that continuously measures the amount of light and reports it to the microcontroller when the measurement exceeds a threshold. This feature further reduces power consumption by decreasing the frequency of I2C communication.

MAX44007/MAX44009 is suitable for tablet and laptop PCs, smartphones, TVs, digital lighting management systems, and light intensity monitoring applications.

Giving more meaning to the sensor

In light sensing systems, differences in the path of light cause measurement differences. These differences are caused by the position of the sensor on the board, the distance tolerance between the top of the sensor and the glass surface, the transmission characteristics of the glass covering the sensor, and many other factors. When component-specific variations in the sensor are added to these factors, the reading error can reach 50%. This leads to false triggers, which can result in a decrease in production yield.

The all-in-one integrated solution provided by the MAX44007/MAX44009 features a maximum total gain error of only 15%. In addition to these highly precise optical measurements, Maxim's optical sensor digital communication is resistant to parasitic elements present in the communication interface. These two features achieve stable and reliable optical measurements, providing excellent production yields.

Perceiving light as the human eye sees

It is difficult to perfectly replicate the human eye's light response using electronic components. Conventional light sensors measure the amount of light present in the environment regardless of wavelength. Such designs are excessively affected by ultraviolet and infrared light, which is imperceptible to the human eye. This leads to inaccurate ambient light readings and significant discrepancies in brightness adjustment. This problem is further exacerbated by the fact that light sources possess different spectra. For example, incandescent bulbs contain more infrared components than fluorescent bulbs.

Maxim's BiCMOS technology eliminates ultraviolet and infrared light by integrating two photodiodes along with an optical filter. Through this implementation, the MAX44007/MAX44009 accurately measures visible light in various environmental settings by replicating the light response of the human eye. Enhanced algorithms correct for all spectral deviations between light sources, ensuring a highly accurate lux response.

Furthermore, the sensor's ADC integration time can be adjusted between 6.25ms and 800ms. The default integration time of 100ms ensures excellent 50Hz/60Hz rejection.

Improvement of black glass properties

Portable devices often use colored or black glass on the top of the sensor. Black glass presents many problems for optical sensors because it alters the response to various light sources with different radiation spectra. Generally, measurement errors occur when these different spectra combine with the spectral profile of the glass.

The MAX44007 provides access to two types of light sensors: visible + infrared photodiodes and infrared photodiodes. Once the designer knows the response of black glass, they can incorporate it into the light sensor measurements to achieve excellent accuracy and sensitivity (as low as 0.025 lux).

Increased dynamic range and precision

The ambient light sensor covers a wide range of light conditions, including all intermediate changes from direct sunlight to complete darkness.