White LED driver market is hot, chip suppliers are fiercely competitive, they have to develop advanced charge pump products in which to figure a place. This charge pump can provide higher backlight power to meet the larger and more complex portable / wireless device color display needs. In addition, manufacturers also advocate the use of backlights in the LED chip can be better to match the brightness of the chip. However, the primary concern for OEMs is how to increase the efficiency of switched-capacitor (charge-pump) power supplies, as well as the use of boost converters to maximize equalization performance. Charge pumps are commonly used to drive parallel-connected LEDs, while boost converters are often used to drive LEDs in series and in series / parallel. Charge pump devices take up much less space, seems to be the first choice for large OEMs. They are favored, in addition to be used for different applications, there is an indirect reason is that people think that the inductor-based power supply may bring insurmountable EMI problems. In fact, the recently introduced topologies for charge pumps are quite common, and the differences between the chips are mainly subtle changes that have been made in specific applications to give users the edge. Tony Armstrong, product sales manager for Linear Technology's Power Division, said: "The market demands that today's devices must have both a primary and secondary display, and at least one RGB display to provide backlighting." He noted the expanding product design requirements. In fact, the company just released the LTC3206 is one such charge pump. He emphasized that the current accuracy (the difference between the LED average current and the expected current) and the matching problem are very complex. "While customers are happy with 10% current accuracy, they complain about matching accuracy (maximum difference between any two LED current sources for a given average current) of more than 5%." Other than that He also mentioned that a frequently overlooked issue is the overall efficiency and the percentage of battery direct-on-time versus power-on in 1.5 or 2-fold mode by the charge pump when the voltage starts to drop.