LCD backlight brightness automatically control circuit ( visible brightness sensor LX1970 )

Published:2012/8/26 22:21:00 Author:Ecco | Keyword: LCD backlight , brightness, automatically control, visible , brightness sensor | From:SeekIC

When the ambient brightness is significantly dimmed, LX1970 can automatically open the LCD backlight to make white LED emit light. Automatic brightness control circuit is shown as the chart. The resistors R1 and R2 can be used to set the minimum and maximum values of controlling brightness. Changing the capacity of the capacitor C can adjust the response time and filter out the 50Hz mains interference. LX1970 uses +3.3 ~ +5 V power supply. If the circuit only uses SRC end, SNK end should be left vacant. Assuming driving white LEDs requires output voltage of 0.25 to 1.25V, 0.25V represents the minimum brightness of the LED, 1.25V represents the maximum brightness.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Control_Circuit/LCD_backlight_brightness_automatically_control_circuit__visible_brightness_sensor_LX1970_.html

Print this Page | Comments | Reading(3)