Patent attributes
An LED driver circuit includes a power controller, a voltage regulator, a detecting resistor, a light emitting device, and a voltage detecting circuit. The voltage detecting circuit has a first input end connected to a higher potential end of the detecting resistor, and a second input end thereof is connected to a lower potential end of the detecting resistor. The output end of the voltage detecting circuit is connected to a feedback end of the power controller so as to output a detected voltage signal to the power controller for adjusting the output voltage and supplying a stable and proper value of current to the light emitting device. The voltage detecting circuit is a differential amplifier capable of detecting the voltage difference between the detecting resistor and amplifying it as a feedback to the power controller. Therefore, the output current from the power controller is precisely controlled.
