LED driver circuit and method for controlling current distribution of LED strings

The LED driving circuit includes a first current source, a second current source, a current sensing circuit, and a control circuit. A first current source coupled in series with the heat dissipation resistor provides a first current path to the LED string. A second current source coupled in parallel with the first current source coupled in series and the heat dissipation resistor provides a second current path to the LED string. The current sensing circuit is configured to sense a current sensing signal characterizing a current flowing through the LED string. The control circuit is configured to control current distribution of the first current path and the second current path in response to a current sense signal. When the current sensing signal is greater than the threshold value, the current flowing through the first current path is greater than the current flowing through the second current path. LED驱动电路包括第一电流源、第二电流源、电流感测电路和控制电路。与散热电阻器串联耦接的第一电流源向LED串提供第一电流路径。与串联耦接的第一电流源和散热电阻器并联耦接的第二电流源向LED串提供第二电流路径。电流感测电路