Abstract: It proposes a circuit about multioutput constant current LED drivers, based on LLC resonant. The LLC resonant was adopted in the DC/DC circuit, improving the frequency of conversion. The switches on the primary side could work in zerovoltageswitching mode(ZVS)，and the diodes on the secondary side could work in zero-current-switching(ZCS)mode，which decreased the loss of switching and improved the efficiency of the system．The balance capacitor was used in the LED driver circuit, and it was easy to achieve the balance of the current. Meanwhile, a prototype was proposed to test in the laboratory. It focused on the mechanism of the resonant and the balance of the current. The system has been simulated and verified, based on PSIM. 

Key words: multioutput LED strings; isolated drive; current balancing; resonant