LX1971

·Approximate Human Eye Spectral Response
·Low IR Sensitivity
·Highly Accurate & Repeatable Output Current vs. Light
·Square root transfer function
·Temperature Stable
·Integrated High Gain Photo Current Amplifiers
·Complementary Current Outputs
·No Optical Filters Needed

The LX1971 is a new technology light sensor with spectral response that emulates the human eye; it is pin to pin compatible to Microsemi's LX1970 visible light sensor however with a wider dynamic range.

This device LX1971 is ideal for monitoring ambient light for the control of artificial lighting, operation of shades, LED signage and display, street lighting, automotive light sensors and control of backlight dimming. It has a unique photo diode arrangement (patents pending) with a peak response at 520nm while sharply attenuating both ultra violet and infrared wavelengths.

The photo sensor LX1971 is a PIN diode array with an accurate and very repeatable current output.Photo current is first multiplied by an integrated high gain amplifier then the square root is taken of the product of the amplifier and an internal reference current. Finally this is further multiplied converted to current and made available at two output pins; one a current source and the other a current sink.

These currents can easily be converted to voltage by adding a single resistor at either or both outputs. Voltage gain is determined by the resistor value typically in the 5KΩ to 50KΩ range.With accurate internal gain amplifiers and square root transfer function, design complexity and cost are greatly reduced. The LX1971 is available in the Clear 8-pin MSOP package.