??? 02/28/11 16:53 Read: times |
#181344 - Voltage regulator as CC? Responding to: ???'s previous message |
Do you know what voltage the backlight needs?
You might be able to use a low voltage low dropout voltage regulator as constant current generator that uses a series resistor to control the current. But this only works if the actual voltage needed for the backlight is less than regulator voltage + dropout voltage. A 3V LDO with 1V dropout would allow max 9-4 = 5V to the backlight. A 1.2V LDO with 0.2V dropout would allow 7.6V regulation range. |