The invention discloses an LED driving
control circuit and a method. The LED driving
control circuit comprises a
voltage comparison module, an output
current threshold control module and an LED driving module, wherein the
voltage comparison module is used for generating a comparison
signal PWM (Pulse-Width Modulation) and providing the comparison
signal PWM to the output
current threshold control module and the LED driving module; the output
current threshold control module is used for generating current threshold
control signal IREF / VREF (Input Reference /
Voltage Reference) to the LED driving module according to the duty factor of the comparison
signal PWM; and the LED driving module is used for generating an LED driving
control signal according to the input current threshold
control signal IREF / VREF and the comparison signal PWM. The product of the duty factor of the current threshold control signal IREF / VREF and the duty factor of the comparison signal PWM is a constant so that
average current output by the LED driving
control circuit is equal under the comparison signal PWM of different duty factors. According to the invention, the influence of the overlarge current change of an
LED lamp when a commercial power is changed can be solved; output current can be set conveniently; and the flickering problem of the
LED lamp resulted from the current change is solved.