The LX1972 is a low cost silicon light sensor with spectral response that closely emulates the human eye. The patented circuit produces a maximum spectral response of 5% nm, less than IR with a response, maximum response, above nm.
The photographic sensor is an array of PIN diodes with a linear, precise and highly repeatable current transfer function.
High-gain current mirrors on the chip multiply the photographic current of the PIN diode at a sensitivity level that can be scaled with an external resistor of standard value. The output current of this simple two-pin device can be used directly or converted to a voltage by placing it in series with a single resistor on either of its two pins.
The dynamic range is determined by the resistors (normally in the range of 10 K to 100 K) and the values of the power supply. Normally, the LX1972 only needs 1.8 V of space to operate at 1000 Lux illumination.
The internal temperature compensation allows the dark current to remain below zero over the full specification.
Temperature range (-40 to + 85 ° C), providing high precision at low light levels. The range of usable ambient light conditions is from 1 to more than 5000 Lux.
The LX1972 is optimized to control back lighting systems in low-cost consumer products such as LCD TVs, laptops and digital cameras.
Spectral response of the nearby human eye.
Very low IR sensitivity.
Highly precise and repeatable output current compared to light.