VISUAL SOLUTIONS

Sensors Simplify Brightness Control in Display Applications

The ISL29001 and ISL29002 from Intersil are visible light sensors that can be used in the brightness control systems of a wide variety of displays. These light to digital output sensors are fully integrated, combining two photodiodes, a current amplifier, 50Hz/60Hz rejection filter and a 15-bit ADC.



The devices achieve a response very similar to that of the human eye, sensing visible light (380nm to 770nm) and converting its intensity to an easy to use 15-bit, I²C standard digital output signal. Peak sensitivity is at 550nm and the sensors reject 50Hz and 60Hz flicker caused by artificial light sources.

Resolution is adjustable, from three counts per lux to 15 counts per lux for the ISL29001 and 0.15 counts per lux to 1.65 counts per lux for the ISL29002. Illumination range can also be set by the designer, from 0.3lux to 10,000lux using the ISL29001; and from 1lux to 100,000lux with the ISL29002.

Both the ISL29001 and ISL29002 offer low power consumption, improving battery life and panel visibility in backlight control applications. In normal operation, they consume less than 300μA of supply current. A software power down mode controlled via the I²C interface disables all but the I²C interface itself, reducing supply current to less than 88μA. A power down pin is also provided which reduces power consumption to less than 1μA.

Designed to operate with power supplies from 2.5V to 3.3V, the devices are supplied in clear Pb-free ODFN packaging. The ISL29001 is specified for operation over the -40°C to +85°C ambient temperature range, the ISL29002 for operation over the 0°C to +70°C range.

Features

• Light to digital output sensors
• Human eye response (peak sensitivity at 550nm)
• Temperature compensated
• 15-bit effective output resolution
• I²C interface
• 2.5V to 3.3V supply supports 5V I²C bus
• Three I²C address selection pins on the ISL29002
• Adjustable resolution
  • 3 to 15 counts per lux (ISL29001)
  • 0.15 to 1.65 counts per lux (ISL29002)
• Adjustable range
  • 0.3lux to 10,000lux (ISL29001)
  • 1lux to 100,000lux range (ISL29002)
• Simple output code directly proportional to lux
• 50Hz/60Hz rejection to eliminate artificial light flicker
• Operating temperature range -40°C to +85°C (ISL29001); 0°C to +70°C (ISL29002)
• Pb free plus anneal packaging (RoHS compliant)

Applications

• Flat panel backlight control
• Keyboard backlight control
• Medical and industrial sensing
• Digital and still cameras
• Intrusion detection
• Lighting controls

For further information, including Datasheets for both products, please
click here