Voltage boosting circuit and method

A voltage booster circuit that prepares an output voltage using an input voltage applied to an input line and provides the output voltage to an output line, the voltage booster circuit comprising:

• J circuit groups arranged in series to each other between the input line and the output line such that each of the J circuit groups includes a charge-accumulating device, a first switch and a second switch, J is equal to or greater than 2, wherein:
• the first and second switches in each respective J circuit group from the input line are connected to each other by one terminal of the first switch and one terminal of the second switch,
• wherein a first circuit group in the J circuit groups is connected to the input line, and wherein a last circuit group in the J circuit groups is connected to the output line,
• the other terminal of the first switch in each of the first through J−1 circuit groups is connected to one terminal of the charge-accumulating device in the respective circuit group and to a connection point of the first and second switches in the subsequent series connected circuit group, and
• the other terminal of the second switch in each of the first through J circuit groups is connected to the other terminal of the charge-accumulating device in the respective circuit group, wherein
• the first switch in a Kth circuit group within the J circuit groups (where K is an integer equal to or greater than two, but less than J) connects the one terminal of the respective charge-accumulating device and one terminal of the charge-accumulating device in the (K−1)th circuit group, to permit the charge-accumulating device in the Kth circuit group to hold a sum voltage of L voltages held by L charge-accumulating devices in L circuit groups in the J circuit groups,
• the second switch in the Kth circuit group adds, to a voltage held by the charge-accumulating device in the Kth circuit group, a sum voltage of M voltages held by M charge-accumulating devices in M circuit groups in the J circuit groups, to prepare a plurality of sum voltages that discretely range from a voltage similar to the input voltage to a voltage 2J times as high as the input voltage, J being a positive integer, K being an integer equal to or smaller than J, and L and M being integers equal to or smaller than J, and
• the output voltage provided by the voltage booster circuit to the output line is selected from any one of a possible plurality of sum voltages within the circuit.