Power supply circuit and LED driving circuit

A power supply circuit configured to receive energy from a power supply and to supply an output current to a load, the power supply circuit comprising:

• a constant current control circuit configured to receive a first voltage and a first current from the power supply, and to generate a second voltage and a second current that are substantially constant, wherein the first voltage and the first current are DC signals;
• an energy storage circuit coupled between two output terminals of the constant current control circuit, wherein the energy storage circuit is configured to provide a supply voltage for the load and compensate variation of the output current;
• and
• a shunt current circuit coupled in parallel with the energy storage circuit and disposed between the constant current control circuit and the energy storage circuit, wherein the shunt current circuit is configured to compensate variation of the output current, and to automatically shunt the second current when the second current is greater than the output current.