Switched capacitor voltage converter circuit and switched capacitor voltage conversion method

A switched capacitor voltage converter circuit configured to convert a first voltage into a second voltage or to convert the second voltage into the first voltage, the switched capacitor voltage converter circuit comprising:

• a switched capacitor converter coupled between the first voltage and second voltage;
• and
• a control circuit configured to generate a control signal to control the switched capacitor converter to convert the first voltage to the second voltage or to convert the second voltage to the first voltage;
• wherein the switched capacitor converter includes:
• at least one resonant capacitor;
• a plurality of switches coupled to the at least one resonant capacitor;
• and
• at least one inductor;
• wherein the control signal generated by the control circuit includes a first operation signal and a second operation signal, wherein the first operation signal is configured to operate first plural switches of the plurality of switches, and the second operation signal is configured to operate second plural switches of the plurality of switches;
• wherein, in a first process, the first operation signal controls the first switches so that the at least one resonant capacitor and a corresponding one of the at least one inductor are connected in series between the first voltage and second voltage, to form a first current path and to operate in resonant operation;
• wherein, in at least one second process, the second operation signal controls the second switches so that the at least one resonant capacitor and the corresponding inductor are connected in series between the second voltage and a DC potential, to simultaneously form or sequentially form a plurality of second current paths and operate in resonant operation;
• wherein the first switches and the second switches have respective conduction periods which do not overlap each other, so that the first process and the second process do not overlap each other;
• wherein the control circuit adjusts an operation frequency and/or a duty ratio of the first operation signal and/or an operation frequency and/or a duty ratio of the second operation signal according to a predetermined ratio, so as to adjust a ratio between the first voltage and second voltage to the predetermined ratio;
• wherein the first process and the at least one second processes are performed in a repeated, alternating manner, so as to convert the first voltage into the second voltage or to convert the second voltage into the first voltage;
• wherein when the control circuit decreases the duty ratio of the first operation signal and/or the second operation signal according to the predetermined ratio, in the first process and/or the second process, when the first switches and/or the second switches are turned ON, an inductor current flowing toward the second voltage is in a first state, wherein the first state is that the inductor current flowing toward the second voltage is a resonant current, and
• wherein when the control circuit decreases the duty ratio of the first operation signal and/or the second operation signal according to the predetermined ratio, in the first process and/or in the second process, the inductor current flowing through the corresponding inductor keeps freewheeling along a current freewheeling path, whereby the inductor current flowing toward the second voltage is in a second state, such that the inductor current of the corresponding inductor is rendered to switch between the first state and the second state, thereby performing inductive power conversion.