Led driving device and control method for led driving device

A LED driving device, comprising:

• a conversion unit comprising at least one first switch to convert an Alternating Current (AC) or Direct Current (DC) input into a DC output that comprises an output current and an output voltage;
• a dimming switch circuit electrically coupled to the conversion unit and a load, and comprising at least one second switch;
• and
• a control unit electrically coupled to the conversion unit and the dimming switch circuit and having a first input terminal to receive a first signal that represents the output voltage, a second input terminal to receive a second signal that represents the output current, a third input terminal to receive a dimming signal, a first output terminal to output a first driving signal to the at least one second switch, and a second output terminal to output a second driving signal to the at least one first switch;
• wherein the control unit comprises:
• a dimming control unit comprising:
• a comparison circuit configured to compare the first signal with a reference signal, and output a first enabling signal and a second enabling signal;
• a constant-voltage dimming circuit electrically coupled to the comparison circuit to receive the first enabling signal, and output the first driving signal according to the dimming signal and the first enabling signal;
• and
• a constant-current dimming circuit electrically coupled to the comparison circuit to receive the second enabling signal, and output a current-reference according to the dimming signal and the second enabling signal, and
• a conversion control unit electrically coupled to the constant-current dimming circuit to receive the current-reference, and output the second driving signal according to the current-reference and the second signal.