Patent ID: 9699839
Date: 2017-07-04
CPC Classifications: H05B,Y02B

Claim:
1. A light-emitting diode (LED) driving circuit, comprising: a) a switching power stage circuit configured to generate a pseudo-constant output current to drive an LED load, wherein said LED load comprises a plurality of LED strings coupled in series between outputs of said switching power stage circuit wherein said plurality of LED strings are controlled by a plurality of pulse-width modulation (PWM) dimming signals to be enabled or disabled from a series LED current path to control average currents flowing through said plurality of LED strings; b) a loop steady state network comprising a plurality of steady state holding components configured to hold a plurality of steady state control signals that correspond to a plurality of load states of said LED load; c) a control loop configured to generate a first control signal in accordance with a current feedback signal that represents said driving current of said LED load and a corresponding one of said plurality of steady state control signals to control operation of said switching power stage circuit; d) a switching decoder coupled to said loop steady state network, wherein said switching decoder is configured to generate a selected steady state signal based on said plurality of PWM dimming signals; and e) a logic circuit coupled to said control loop and configured to generate a gate control signal to control operation of a power switching transistor of said switching power stage circuit in accordance with said first control signal and said plurality of PWM dimming signals.