43.2: A Charge-Reservoir with Buck-Store and Boost-Restore (BSBR) Technique for High Efficient Conversion and Low Cost Solution of RGB LED Display Panels

A boost converter with buck-store and boost-restore(BSBR) technique fabricated by 0.25μm CMOS BCD process can provide different supply voltages to drive series RGB LEDs in sequence for reducing the power consumption on the constant current generator. The proposed technique not only stores and restores extra charge during the transient time of the reference tracking response to improve the efficiency but also enhances the reference tracking response to greatly reduce load transition time. Experimental results show that the period of reference-tracking response can be improved. When the load current is 100mA, the periods of reference down-tracking and up-tracking are smaller than 10μs and 20μs, respectively. Furthermore, this technique also can provide a regulated voltage to drive the sub-block implemented in the LCD system. The maximum efficiency of charge recycling is up to 94% and the maximum efficiency of this boost converter is 92.5%. Experimental results demonstrate fast and efficient reference tracking performance is achieved by the proposed BSBR technique.