LED lighting systems with TRIAC dimmers and methods thereof

A system for controlling one or more light emitting diodes, the system comprising:

• a current regulation circuit configured to receive a rectified voltage and coupled to an anode of one or more light emitting diodes, the one or more light emitting diodes including the anode and a cathode;
• and
• a control circuit configured to receive the rectified voltage;
• wherein the control circuit is configured to:
• compare an input voltage and a threshold voltage, the input voltage indicating a magnitude of the rectified voltage;
• and
• generate a control signal based at least in part on the input voltage and the threshold voltage;
• wherein the control circuit is further configured to:
• if the input voltage is larger than the threshold voltage, generate the control signal at a first logic level;
• and
• if the input voltage is smaller than the threshold voltage, generate the control signal at a second logic level;
• wherein the current regulation circuit is configured to:
• receive the control signal from the control circuit;
• allow a current to flow through the one or more light emitting diodes if the control signal is at the first logic level, the current being larger than zero in magnitude;
• and
• not allow the current to flow through the one or more light emitting diodes if the control signal is at the second logic level;
• wherein the current regulation circuit includes:
• an amplifier including a first amplifier input terminal, a second amplifier input terminal, and an amplifier output terminal;
• a transistor including a drain terminal, a gate terminal, and a source terminal;
• and
• a resistor including a first resistor terminal and a second resistor terminal;
• wherein:
• the drain terminal of the transistor is configured to receive the rectified voltage;
• the gate terminal of the transistor is coupled to the amplifier output terminal of the amplifier;
• and
• the source terminal of the transistor is coupled to the anode of the one or more light emitting diodes.