New open loop control technique of boost converter to mitigate temperature impact for LED applications

A new open loop control technique of boost converter to mitigate the temperature effect on current control of LED driver will be presented. The presented open loop control technique achieves zero voltage turn on in order to significantly reduce the reverse recovery loss of diode and mitigates the temperature impact on the constant current control. The basic idea of the presented control technique is to on-line calculate the on-time of power device as input voltage changes and then tune the off-time to achieve zero voltage switching even with temperature variation. Experimental results derived from a digital-controlled boost converter for LED driver will be presented. The specifications include: input voltage = 15 V and output current is 280 mA. Experimental results show the current can be retained even though the temperature of LED varies using the proposed open loop control technique.