In recent years, we have been using a lot of equipment in which high performance rechargeable batteries such as lithium-ion and nickel-metal-hydride are built. These chargers require accurate constant-voltage and constant-current. A high performance switching converter with digital control is used with a voltage-current control method. The switching converter using this method has good voltage stability. However, for constant-current control, a current sampling value changes because of the switching charier ripple current flowing in a reactor. Therefore, current stability dose not satisfy high accurate specification. Improving the problem, this paper proposes the switching converter with π type filter. The circuit improves the current stability so as not to change the sampling current value. However, it is difficult for the voltage control to stabilize using only voltage feedback because the circuit is the third order lag system. So, the proposed converter can stabilize both the output voltage and current by applying the voltage-current control method. Using the proposed method, the measured output characteristics have been obtained satisfied results. The proposed method is practical as the charging method for high performance rechargeable batteries.

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