LED dimming control circuit, dimming control method and LED power system thereof

A light-emitting diode (LED) dimming control circuit, comprising:

• a) a detection circuit configured to receive a dimming control signal, and to generate a detection signal for characterizing a type of the dimming control signal by detecting a number of rising or falling edges of the dimming control signal within a period of time by counting transitions of a clock signal that is generated by comparing the diming control signal against a reference voltage;
• b) a dimming signal generation circuit configured to generate a dimming signal according to the detection signal and the dimming control signal, wherein a duty cycle of the dimming signal corresponds to the dimming control signal;
• and
• c) a first conversion circuit configured to compare the dimming control signal against a triangular wave signal to generate a comparison result that is high when the triangular wave signal is greater than the dimming control signal.