In view that there are three LED strings in this example, during operation of multichannel constant current LED controlling circuit 400, there are total 2³=8 load states. Outside of the load state whereby all LED strings are turned off, for the remaining 7 load states, corresponding compensation capacitor(s) of loop steady state network 404 can be coupled to the control loop. When a load state occurs for the first time, the compensation capacitor of loop steady state network 404 can store the steady state signal of corresponding load state. When the load state occurs again, because the steady state signal has been stored by the compensation capacitor(s) in prior switching periods, the corresponding compensation capacitor(s) can be coupled to the control loop in order to directly obtain the steady state signal of loop steady state network 404.

Switching decoder 405 and loop steady state network 404 can select corresponding steady state signal in accordance with the PWM dimming signals. The number N of the compensation elements (e.g., capacitors) can be related to the number M of the LED strings of the LED load, where N and M are both positive integers. Loop steady state network 404 can provide the steady state signal corresponding to one load state when the LED load varies. For example, N=2^M?1, may indicate that loop steady state network 404 can provide corresponding steady state control signals for all the load states except when all LED strings are turned off. Also for example, N=2^M, may indicate that loop steady state network 404 can provide corresponding steady state control signals for all the load states.