For a realization of a DC-DC converter using no magnetic devices, a new switched capacitor (SC) transformer is introduced, which gives voltage ratios by Fibonacci series corresponding to the stages. This transformer is connected in cascade by each basic block which is assembled by a capacitor and three MOSFET switches. This operates on a simple two-phase clock and has a large step-up or step-down voltage ratio in spite of its simple configuration. The characteristics of this transformer with n stages of basic block are derived and calculated by means of a 4 4 cascade matrix. The optimal arrangement of each stage's capacitances is shown to reduce the SC resistance by about 20%. The simulation results are compared with the characteristics of a prototype transformer with four stages (8 times step-up ratio). Its power efficiency achieves 88% in case of 97 V output voltage, 0.2 A output current, and 100 kHz switching frequency. Lastly, the proposed SC transformer is compared and discussed with other typical SC transformers.

New AC-DC converters using switched-capacitor (SC) transformers are presented. The features of these circuits are as follows. (1) It does not contain any magnetic material. (2) The inrush current of the proposed converter is very small as compared with that of a condenser-input-type rectifier circuit. (3) It is realizable in a hybrid IC form. (4) It excels in size and weight when compared with reactor-type switching regulators of the same output power. As an example, an AC-DC converter using step-up SC transformers was built and tested to confirm the characteristics. The measured characteristics showed good agreement with the calculated ones.

in this paper, the steady-state and dynamic analyses of the continuous and the discontinuous conduction mode of the uk converter with nonzero mutual inductance by the state-space averaging method are described. For the analysis of the discontinuous conduction mode of the uk converter, the critical duty ratio is used. The analysis of the dynamic responses is presented for both the open- and closed-loop cases. The obtained results are useful for the optimum design of the uk converters.

An AC-DC converter using a new switched-capacitor (SC) transformer and its design are presented. The features of this circuit are as follows. (1) The maximum voltage of capacitors is 1/n times that of a condenser-input-type rectificer circuit, where n is the number of chargetransfer capacitors. (2) The output voltage ripple is small, since the equivalent smoothing capacitor value is n times that of conventional SC transformers (series-parallel switching type). Using the presented design method, each element value is designed from the specifications of a test circuit. The experimental results of the test circuit show that (1) the efficiency of the SC transformer is very high (95%), and the total efficiency is 74% due to the losses of the clock generator and the control circuit, (2) the maximum output power is 40 W, (3) the value of the inrush current of the tested converter is only twice the value of the steady state current. The measured characteristics showed good agreement with the calculated ones.

Two algorithms are presented for a time-domain analysis of a switching converter which is replaceable with a piecewise-linear system. One of them is for the transient state analysis and the other is for the steady-state analysis. Both of them use the eigen-value and the eigen-vector calculations. The analysis based on these algorithms can be carried out more rapidly and accurately than the conventional analysis using standard fixed or variable step-size integration methods. On the uk converter, the results of the proposed method are compared with those of the Hamming method (a variable step integration method) and of SPICE2 (a general-purpose circuit analysis program using variable step-size integration method).

Three types of momentary power-failure detectors are presented here. These are commonly adopting novel type time-to-voltage (T-V) conversion which is realized by using switched-capacitor (SC) integrators. They can monitor and detect power failures lasting more than one cycle of an AC power source. Then they active a signal and start to generate auxiliary pulses synchronized to the AC power frequency through the power failure time. Their operating frequency ranges are from several tens Hz to several kHz covering almost AC power source frequencies, without any adjustment. The period of the auxiliary pulses is confirmed to be very stable as experimental results.