ROHM | BH1721FVC-TR

ROHM’s ambient light sensor (ALS) lineup offers a simple solution for reducing power consumption in a variety of LCD-equipped portable electronic devices. For example; in a cell phone, the ALS enables automatic control of display backlight brightness over a wide range of illumination conditions from a dark environment to direct sunlight. In conjunction with the input of a ROHM ALS, a microcontroller (MCU) or baseband processor increases or decreases the display brightness depending on the environment. This control dramatically improves visibility and reduces power consumption since LCD backlight­ing can draw as much as 51% of the power in the input standby mode. In addition, the ALS signal can be used to instruct the keypad LED driver to minimize keypad backlighting reducing up to 30% of the power in the input standby power mode.

ROHM offers both analog and digital ambient light sensor ICs that have spectral sensitivity similar to the human eye. This is important since wavelengths outside of the range of human vision, such as ultraviolet and infrared, may cause inaccurate light sensor read­ings. Both digital and analog parts are offered in compact, surface-mount packages - the WSOF5 package (1.6 x 1.6 x 0.55 mm) as well as the WSOF6 package (3.0 x 1.6 x 0.7 mm).

ROHM’s analog ALS ICs feature light sensing accuracy of ±15% based on our unique laser trimming technology that also ensures stable output sensitivity. This technology also allows ROHM’s ALS products to surpass the competition in light detection precision by ~30-50%. Additionally, ROHM’s analog ALS products have selectable high-gain, medium-gain and low-gain modes allowing for compatibility with a wide range of brightness levels. These gain modes provide engineers with even greater design flexibility by allowing the option of trading performance versus power consumption.

Among the first manufacturers to offer a digital ambient light sensor, ROHM’s digital ALS devices contain built-in high accuracy A/D converters, thus ensuring precise measurements over a wide range of lighting conditions. These parts also offer two resolution modes; the H-resolution mode has the highest resolution (1 lux increments) and is suitable for measuring very low lux levels, but takes the longest time to measure a light sample. The L-resolution mode samples in 4 lux increments and takes the shortest time to measure a light sample.

Series Features:

-          Analog and digital devices

-          Spectral sensitivity close to that of human eye

-          Selectable current gain modes (Analog type)

-          Selectable resolution (Digital type)

-          Built-in shutdown function

-          Compact WSOF5 and WSOF6 packaging

-          RoHS compliantThe BH1721FVC has a digital 16bit serial I2C output and comes in a WSOF5 packaging size (1.6 x 1.6 x 0.55 mm).  The supply voltage range is 2.4V to 3.6V.  It has sensitivity variations of ±15%, an illuminance range of 0-65,000 lx, and is Lead-Free/RoHS compliant.