LX1972 Mini Evaluation Board ® TM LX1972 Light Sensor SCHEMATIC WWW . Microsemi .C OM VDD R1 50K J1 C1 4.7uF VO1 1 LX1972 2 VO2 R2 50K J2 C2 4.7uF PHOTO The design of the LX1972 Mini Light Sensor Evaluation Board easily interfaces to allow control of virtually any lighting requirement. Changing the resistor values sets the desired minimum and maximum brightness range. As configured, there is considerable gain at lower light levels (from < 1lux to about 300lux with a 5V VDD). Output voltage is ground referenced (as configured VO2) or moving the jumper from J1 to J2 changes the voltage reference to VDD at VO1. The J1 and J2 locations also allow placing a second resistor in parallel to modify the light conversion gain; this will allow a wider light range (with less overall resolution). VDD = 3V to 5.5V PACKAGE PIN OUT VO1 = I SNK × R1 (if J1 Open) BC PACKAGE VO2 ≈ 3V (Top View) Protected By U.S. Patents: 6,787,757; Patents Pending FUNCTIONAL PIN DESCRIPTION NAME 1/27/2005 Rev 1.1a DESCRIPTION VDD Input Supply Voltage GND Ground Reference for Power and Signal Outputs Microsemi Integrated Products 11861 Western Avenue, Garden Grove CA. 92841 714-898-8121, FAX: 714-893-2570 LX1972 @ Total Dark VO2 < 10mV @ 300 lux 2 1 If VDD = 5V then : VSS VDD VO2 = I SRC × R2