US 12,136,875 B2
Switched capacitor voltage converter circuit and switched capacitor voltage conversion method
Kuo-Chi Liu, Hsinchu (TW); and Ta-Yung Yang, Taoyuan (TW)
Assigned to RICHTEK TECHNOLOGY CORPORATION, Zhubei (TW)
Filed by Richtek Technology Corporation, Zhubei (TW)
Filed on Oct. 25, 2022, as Appl. No. 18/049,622.
Claims priority of provisional application 63/287,483, filed on Dec. 8, 2021.
Claims priority of application No. 111121086 (TW), filed on Jun. 7, 2022.
Prior Publication US 2023/0179093 A1, Jun. 8, 2023
Int. Cl. H02M 3/07 (2006.01); H02M 1/00 (2006.01); H02M 3/00 (2006.01)
CPC H02M 3/07 (2013.01) [H02M 1/0009 (2021.05); H02M 3/015 (2021.05)] 20 Claims
OG exemplary drawing
 
1. A switched capacitor voltage converter circuit, which is configured to convert a first voltage to a second voltage or convert the second voltage to the first voltage; the switched capacitor voltage converter circuit comprising:
a switched capacitor converter coupled between the first voltage and the second voltage; and
a control circuit, which is configured to generate a control signal for controlling the switched capacitor converter, so as to convert the first voltage to the second voltage or convert the second voltage to the first voltage;
wherein the switched capacitor converter includes:
at least two capacitors;
a plurality of switches, which are coupled to the at least two capacitors; and
at least one inductor;
wherein the control circuit is configured to select a ratio of the first voltage to the second voltage according to a level of the first voltage, so that the second voltage is maintained at a first predetermined range, and to generate the control signal accordingly, so as to convert the first voltage to the second voltage, or wherein the control circuit is configured to select the ratio of the first voltage to the second voltage according to a level of the second voltage, so that the first voltage is maintained at a second predetermined range, and to generate the control signal accordingly, so as to convert the second voltage to the first voltage;
wherein the control signal further includes: a charging operation signal and at least one discharging operation signal;
wherein in a charging process of a resonant operation mode, the charging operation signal is configured to control the plurality of switches, so that a series connection of the at least two capacitors and the at least one inductor is formed between the first voltage and the second voltage, to form a charging path and operate in the resonant operation mode;
wherein in at least one discharging process of the resonant operation mode, the at least one discharging operation signal is configured to control the plurality of switches, so that a series connection of each respective capacitor of the at least two capacitors and the at least one inductor is formed between the second voltage and a DC voltage level, to simultaneously or sequentially form a plurality of discharging paths and operates in the resonant operation mode;
wherein in the resonant operation mode, the charging operation signal and the at least one discharging operation signal have respective ON periods which do not overlap one another, so that the charging process and the at least one discharging process do not overlap each other;
wherein in the resonant operation mode, the charging process and the at least one discharging process are arranged in a repeated, alternating order, so as to convert the first voltage to the second voltage or convert the second voltage to the first voltage;
wherein said control signal further includes an inductor operation signal, which is configured to control the plurality of switches, so that the switched capacitor converter operates in an inductor switching mode, wherein one end of the at least one inductor is alternatingly coupled to the first voltage or to the DC voltage level, so as to convert the first voltage to the second voltage and maintain the second voltage within the first predetermined range or to convert the second voltage to the first voltage and maintain the first voltage within the second predetermined range;
wherein the inductor switching mode includes: a 2-level inductor switching mode or a 3-level inductor switching mode, and wherein the inductor operation signal includes: a 2-level inductor operation signal or a 3-level inductor operation signal;
wherein in the 2-level inductor switching mode, the 2-level inductor operation signal controls the plurality of switches, so that a voltage at the one end of the at least one inductor is periodically switched between the first voltage and the DC voltage level, so as to convert the first voltage to the second voltage or convert the second voltage to the first voltage;
wherein in the 3-level inductor switching mode, the 3-level inductor operation signal controls the plurality of switches, so that the voltage at the one end of the at least one inductor is periodically switched among the first voltage, ½-fold of the first voltage and the DC voltage level, so as to convert the first voltage to the second voltage or convert the second voltage to the first voltage; and
wherein the control circuit decides to control the switched capacitor converter to operate in one of, according to the first voltage: a 2-to-1 mode, a 3-to-1 mode, the 2-level inductor switching mode, or the 3-level inductor switching mode, so as to maintain the second voltage within the first predetermined range.