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US-20260128673-A1 - SWITCHED-CAPACITOR VOLTAGE CONVERTER, CHIP, AND ELECTRONIC DEVICE

US20260128673A1US 20260128673 A1US20260128673 A1US 20260128673A1US-20260128673-A1

Abstract

Provided are a switched-capacitor voltage converter, a chip, and an electronic device. The switched-capacitor voltage converter performs a buck or boost operation on the input voltage based on the different charging and discharging states of the capacitors and the different states of the first and second branches in different stages. The current of the transistors in the switched-capacitor voltage converter may be instantaneously zero, thereby significantly reducing the switching loss of the transistors. Moreover, the capacitors are not subject to conduction loss, such that the power loss of the switched-capacitor voltage converter is further reduced.

Inventors

  • Hongyang XIE
  • Liuniu GUO

Assignees

  • Zhuhai Nanxin Semiconductor Technology Co., Ltd.

Dates

Publication Date
20260507
Application Date
20251106
Priority Date
20241106

Claims (20)

  1. 1 . A switched-capacitor voltage converter, comprising: a controller, a first transistor, and at least one conversion assembly; wherein a first terminal of the first transistor is electrically connected to the at least one conversion assembly, a second terminal of the first transistor is grounded, and a control terminal of the first transistor is electrically connected to the controller; the switched-capacitor voltage converter comprises a first terminal and a second terminal, wherein the at least one conversion assembly is electrically connected between the first terminal and the second terminal of the switched-capacitor voltage converter, each of the at least one conversion assembly comprises a capacitor and a plurality of transistors, and the at least one conversion assembly comprises a first branch and a second branch, wherein the first branch and the second branch share the capacitor; in a case that the switched-capacitor voltage converter operates in a boost mode: in a first stage, the first branch is in a charging state, the at least one conversion assembly is cascaded and is grounded via the first transistor, the second branch is in a disconnected state, an input voltage is present at the first terminal of the switched-capacitor voltage converter, and no output voltage is present at the second terminal of the switched-capacitor voltage converter; and in a second stage, the first branch is in a disconnected state, the second branch is in a discharging state, an input voltage is present at the first terminal of the switched-capacitor voltage converter, and an output voltage is present at the second terminal of the switched-capacitor voltage converter; and in a case that the switched-capacitor voltage converter operates in a buck mode: in a third stage, the second branch is in the charging state, the first branch is in a disconnected state, an input voltage is present at the second terminal of the switched-capacitor voltage converter, and an output voltage is present at the first terminal of the switched-capacitor voltage converter; and in a fourth stage, the first branch is in the discharging state, the at least one conversion assembly is cascaded and is grounded via the first transistor, the second branch is in a disconnected state, no input voltage is present at the second terminal of the switched-capacitor voltage converter, and an output voltage is present at the first terminal of the switched-capacitor voltage converter.
  2. 2 . The switched-capacitor voltage converter according to claim 1 , wherein each of the at least one conversion assembly comprises: a second transistor, a third transistor, a fourth transistor, and the capacitor; wherein a first terminal of the third transistor is electrically connected to the second terminal of the switched-capacitor voltage converter, a second terminal of the third transistor is electrically connected to a first terminal of the capacitor, and a control terminal of the third transistor is electrically connected to the controller; a first terminal of the fourth transistor is electrically connected to the first terminal of the switched-capacitor voltage converter, a second terminal of the fourth transistor is electrically connected to a second terminal of the capacitor, and a control terminal of the fourth transistor is electrically connected to the controller; and a first terminal of the second transistor is electrically connected between the second terminal of the third transistor and the first terminal of the capacitor, a second terminal of the second transistor is electrically connected to the first terminal of the switched-capacitor voltage converter or is electrically connected to an adjacent one of the at least one conversion assembly, and a control terminal of the second transistor is electrically connected to the controller.
  3. 3 . The switched-capacitor voltage converter according to claim 2 , wherein in the first stage, the first transistor and the second transistor are turned on, the third transistor and the fourth transistor are turned off, and the capacitor is in the charging state; and in the second stage, the first transistor and the second transistor are turned off, the third transistor and the fourth transistor are turned on, and the capacitor is in the discharging state; and in the third stage, the first transistor and the second transistor are turned off, the third transistor and the fourth transistor are turned on, and the capacitor is in the charging state; and in the fourth stage, the first transistor and the second transistor are turned on, the third transistor and the fourth transistor are turned off, and the capacitor is in the discharging state.
  4. 4 . The switched-capacitor voltage converter according to claim 2 , wherein in a case that a number of the at least one conversion assembly is one: in the one conversion assembly, the second terminal of the second transistor is electrically connected to the first terminal of the switched-capacitor voltage converter; and the first terminal of the first transistor is electrically connected between the second terminal of the capacitor and the second terminal of the fourth transistor in the one conversion assembly.
  5. 5 . The switched-capacitor voltage converter according to claim 2 , wherein in a case that a number of the at least one conversion assembly is greater than one, the plurality of conversion assemblies are connected in series; wherein a second terminal of the second transistor in a first one of the plurality of conversion assemblies is electrically connected to the first terminal of the switched-capacitor voltage converter, and a second terminal of the second transistor in each of remaining ones of the plurality of conversion assemblies is electrically connected to a first terminal of the capacitor in an adjacent conversion assembly; and a second terminal of the capacitor in a last one of the plurality of conversion assemblies is electrically connected to the first terminal of the first transistor.
  6. 6 . The switched-capacitor voltage converter according to claim 1 , wherein in a case that the switched-capacitor voltage converter operates in the boost mode and a number of the at least one conversion assembly is N, wherein N is a positive integer, a ratio of a magnitude of an input voltage of the switched-capacitor voltage converter to a magnitude of an output voltage of the switched-capacitor voltage converter is N:(N+1); or in a case that the switched-capacitor voltage converter operates in the buck mode and a number of the at least one conversion assembly is N, wherein N is a positive integer, a ratio between a magnitude of an input voltage of the switched-capacitor voltage converter and a magnitude of an output voltage of the switched-capacitor voltage converter is (N+1):N.
  7. 7 . The switched-capacitor voltage converter according to claim 1 , further comprising: a fifth transistor; wherein a first terminal of the fifth transistor is electrically connected to the first terminal or the second terminal of the switched-capacitor voltage converter, a second terminal of the fifth transistor is electrically connected to a load, and a control terminal of the fifth transistor is electrically connected to the controller; the switched-capacitor voltage converter is configured to supply a voltage to the load in a case that the fifth transistor is turned on; or the switched-capacitor voltage converter is configured to not supply a voltage to the load in a case that the fifth transistor is turned off.
  8. 8 . The switched-capacitor voltage converter according to claim 7 , further comprising: a sixth transistor; wherein a first terminal of the sixth transistor is electrically connected to the first terminal of the switched-capacitor voltage converter, a second terminal of the sixth transistor is electrically connected to the load, and a control terminal of the sixth transistor is electrically connected to the controller; in response to a first instruction from the controller, the fifth transistor is turned off, the sixth transistor is turned on, and the switched-capacitor voltage converter does not supply the voltage to the load; or in response to a second instruction from the controller, the fifth transistor is turned on, the sixth transistor is turned off, and the switched-capacitor voltage converter supplies the voltage to the load.
  9. 9 . A chip, comprising: a switched-capacitor voltage converter, wherein the switched-capacitor voltage converter comprises: a controller, a first transistor, and at least one conversion assembly; wherein a first terminal of the first transistor is electrically connected to the at least one conversion assembly, a second terminal of the first transistor is grounded, and a control terminal of the first transistor is electrically connected to the controller; the switched-capacitor voltage converter comprises a first terminal and a second terminal, wherein the at least one conversion assembly is electrically connected between the first terminal and the second terminal of the switched-capacitor voltage converter, each of the at least one conversion assembly comprises a capacitor and a plurality of transistors, and the at least one conversion assembly comprises a first branch and a second branch, wherein the first branch and the second branch share the capacitor; in a case that the switched-capacitor voltage converter operates in a boost mode: in a first stage, the first branch is in a charging state, the at least one conversion assembly is cascaded and is grounded via the first transistor, the second branch is in a disconnected state, an input voltage is present at the first terminal of the switched-capacitor voltage converter, and no output voltage is present at the second terminal of the switched-capacitor voltage converter; and in a second stage, the first branch is in a disconnected state, the second branch is in a discharging state, an input voltage is present at the first terminal of the switched-capacitor voltage converter, and an output voltage is present at the second terminal of the switched-capacitor voltage converter; and in a case that the switched-capacitor voltage converter operates in a buck mode: in a third stage, the second branch is in the charging state, the first branch is in a disconnected state, an input voltage is present at the second terminal of the switched-capacitor voltage converter, and an output voltage is present at the first terminal of the switched-capacitor voltage converter; and in a fourth stage, the first branch is in the discharging state, the at least one conversion assembly is cascaded and is grounded via the first transistor, the second branch is in a disconnected state, no input voltage is present at the second terminal of the switched-capacitor voltage converter, and an output voltage is present at the first terminal of the switched-capacitor voltage converter.
  10. 10 . The chip according to claim 9 , wherein each of the at least one conversion assembly comprises: a second transistor, a third transistor, a fourth transistor, and the capacitor; wherein a first terminal of the third transistor is electrically connected to the second terminal of the switched-capacitor voltage converter, a second terminal of the third transistor is electrically connected to a first terminal of the capacitor, and a control terminal of the third transistor is electrically connected to the controller; a first terminal of the fourth transistor is electrically connected to the first terminal of the switched-capacitor voltage converter, a second terminal of the fourth transistor is electrically connected to a second terminal of the capacitor, and a control terminal of the fourth transistor is electrically connected to the controller; and a first terminal of the second transistor is electrically connected between the second terminal of the third transistor and the first terminal of the capacitor, a second terminal of the second transistor is electrically connected to the first terminal of the switched-capacitor voltage converter or is electrically connected to an adjacent one of the at least one conversion assembly, and a control terminal of the second transistor is electrically connected to the controller.
  11. 11 . The chip according to claim 10 , wherein in the first stage, the first transistor and the second transistor are turned on, the third transistor and the fourth transistor are turned off, and the capacitor is in the charging state; and in the second stage, the first transistor and the second transistor are turned off, the third transistor and the fourth transistor are turned on, and the capacitor is in the discharging state; and in the third stage, the first transistor and the second transistor are turned off, the third transistor and the fourth transistor are turned on, and the capacitor is in the charging state; and in the fourth stage, the first transistor and the second transistor are turned on, the third transistor and the fourth transistor are turned off, and the capacitor is in the discharging state.
  12. 12 . The chip according to claim 10 , wherein in a case that a number of the at least one conversion assembly is one: in the one conversion assembly, the second terminal of the second transistor is electrically connected to the first terminal of the switched-capacitor voltage converter; and the first terminal of the first transistor is electrically connected between the second terminal of the capacitor and the second terminal of the fourth transistor in the one conversion assembly.
  13. 13 . The chip according to claim 10 , wherein in a case that a number of the at least one conversion assembly is greater than one, the plurality of conversion assemblies are connected in series; wherein a second terminal of the second transistor in a first one of the plurality of conversion assemblies is electrically connected to the first terminal of the switched-capacitor voltage converter, and a second terminal of the second transistor in each of remaining ones of the plurality of conversion assemblies is electrically connected to a first terminal of the capacitor in an adjacent conversion assembly; and a second terminal of the capacitor in a last one of the plurality of conversion assemblies is electrically connected to the first terminal of the first transistor.
  14. 14 . The chip according to claim 9 , wherein in a case that the switched-capacitor voltage converter operates in the boost mode and a number of the at least one conversion assembly is N, wherein N is a positive integer, a ratio of a magnitude of an input voltage of the switched-capacitor voltage converter to a magnitude of an output voltage of the switched-capacitor voltage converter is N:(N+1); or in a case that the switched-capacitor voltage converter operates in the buck mode and a number of the at least one conversion assembly is N, wherein N is a positive integer, a ratio between a magnitude of an input voltage of the switched-capacitor voltage converter and a magnitude of an output voltage of the switched-capacitor voltage converter is (N+1):N.
  15. 15 . The chip according to claim 9 , wherein the switched-capacitor voltage converter further comprises: a fifth transistor; wherein a first terminal of the fifth transistor is electrically connected to the first terminal or the second terminal of the switched-capacitor voltage converter, a second terminal of the fifth transistor is electrically connected to a load, and a control terminal of the fifth transistor is electrically connected to the controller; the switched-capacitor voltage converter is configured to supply a voltage to the load in a case that the fifth transistor is turned on; or the switched-capacitor voltage converter is configured to not supply a voltage to the load in a case that the fifth transistor is turned off.
  16. 16 . The chip according to claim 15 , wherein the switched-capacitor voltage converter further comprises: a sixth transistor; wherein a first terminal of the sixth transistor is electrically connected to the first terminal of the switched-capacitor voltage converter, a second terminal of the sixth transistor is electrically connected to the load, and a control terminal of the sixth transistor is electrically connected to the controller; in response to a first instruction from the controller, the fifth transistor is turned off, the sixth transistor is turned on, and the switched-capacitor voltage converter does not supply the voltage to the load; or in response to a second instruction from the controller, the fifth transistor is turned on, the sixth transistor is turned off, and the switched-capacitor voltage converter supplies the voltage to the load.
  17. 17 . An electronic device, comprising: a chip, wherein the chip comprises a switched-capacitor voltage converter, wherein the switched-capacitor voltage converter comprises: a controller, a first transistor, and at least one conversion assembly; wherein a first terminal of the first transistor is electrically connected to the at least one conversion assembly, a second terminal of the first transistor is grounded, and a control terminal of the first transistor is electrically connected to the controller; the switched-capacitor voltage converter comprises a first terminal and a second terminal, wherein the at least one conversion assembly is electrically connected between the first terminal and the second terminal of the switched-capacitor voltage converter, each of the at least one conversion assembly comprises a capacitor and a plurality of transistors, and the at least one conversion assembly comprises a first branch and a second branch, wherein the first branch and the second branch share the capacitor; in a case that the switched-capacitor voltage converter operates in a boost mode: in a first stage, the first branch is in a charging state, the at least one conversion assembly is cascaded and is grounded via the first transistor, the second branch is in a disconnected state, an input voltage is present at the first terminal of the switched-capacitor voltage converter, and no output voltage is present at the second terminal of the switched-capacitor voltage converter; and in a second stage, the first branch is in a disconnected state, the second branch is in a discharging state, an input voltage is present at the first terminal of the switched-capacitor voltage converter, and an output voltage is present at the second terminal of the switched-capacitor voltage converter; and in a case that the switched-capacitor voltage converter operates in a buck mode: in a third stage, the second branch is in the charging state, the first branch is in a disconnected state, an input voltage is present at the second terminal of the switched-capacitor voltage converter, and an output voltage is present at the first terminal of the switched-capacitor voltage converter; and in a fourth stage, the first branch is in the discharging state, the at least one conversion assembly is cascaded and is grounded via the first transistor, the second branch is in a disconnected state, no input voltage is present at the second terminal of the switched-capacitor voltage converter, and an output voltage is present at the first terminal of the switched-capacitor voltage converter.
  18. 18 . The electronic device according to claim 17 , wherein each of the at least one conversion assembly comprises: a second transistor, a third transistor, a fourth transistor, and the capacitor; wherein a first terminal of the third transistor is electrically connected to the second terminal of the switched-capacitor voltage converter, a second terminal of the third transistor is electrically connected to a first terminal of the capacitor, and a control terminal of the third transistor is electrically connected to the controller; a first terminal of the fourth transistor is electrically connected to the first terminal of the switched-capacitor voltage converter, a second terminal of the fourth transistor is electrically connected to a second terminal of the capacitor, and a control terminal of the fourth transistor is electrically connected to the controller; and a first terminal of the second transistor is electrically connected between the second terminal of the third transistor and the first terminal of the capacitor, a second terminal of the second transistor is electrically connected to the first terminal of the switched-capacitor voltage converter or is electrically connected to an adjacent one of the at least one conversion assembly, and a control terminal of the second transistor is electrically connected to the controller.
  19. 19 . The electronic device according to claim 18 , wherein in the first stage, the first transistor and the second transistor are turned on, the third transistor and the fourth transistor are turned off, and the capacitor is in the charging state; and in the second stage, the first transistor and the second transistor are turned off, the third transistor and the fourth transistor are turned on, and the capacitor is in the discharging state; and in the third stage, the first transistor and the second transistor are turned off, the third transistor and the fourth transistor are turned on, and the capacitor is in the charging state; and in the fourth stage, the first transistor and the second transistor are turned on, the third transistor and the fourth transistor are turned off, and the capacitor is in the discharging state.
  20. 20 . The electronic device according to claim 18 , wherein in a case that a number of the at least one conversion assembly is one: in the one conversion assembly, the second terminal of the second transistor is electrically connected to the first terminal of the switched-capacitor voltage converter; and the first terminal of the first transistor is electrically connected between the second terminal of the capacitor and the second terminal of the fourth transistor in the one conversion assembly.

Description

CROSS REFERENCE TO THE RELATED APPLICATIONS This application is based upon and claims priority to Chinese Patent Application No. 202411582876.1. filed on November 6, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD The present disclosure relates to the technical field of power management chips, and in particular, relates to a switched-capacitor voltage converter, a chip, and an electronic device. BACKGROUND In the related art, a voltage converter of a switching power supply is typically used to convert an input voltage into an output voltage that is the same as or different from the input voltage in terms of magnitude. In such a voltage converter of a switching power supply, the input voltage is boosted or bucked based on energy storage of an inductor and adjustment of a duty cycle of transistors within a switched-capacitor voltage converter. However, due to a large equivalent resistance of the inductor and a freewheeling current generated by the inductor at an instant the switched-capacitor voltage converter is switched on or off, the voltage converter of the switching power supply suffers from significant power loss. Consequently, the efficiency of the voltage converter of the switching power supply is limited, and thus the voltage converter of the switching power supply is unsuitable for high-load applications. For example, batteries with a low shutdown voltage are widely used in production and daily life due to their excellent performance. However, the low shutdown voltage of such batteries fails to meet full-power output requirements of most electronic components in electronic devices. Therefore, it is necessary to perform voltage conversion on the voltage output by the battery with a low shutdown voltage using a voltage converter of a switching power supply. The voltage converted by the voltage converter of the switching power supply is then supplied to the electronic device to power the electronic components thereof. In a case where a voltage converter of a switching power supply is employed to boost the voltage output from a battery with a low shutdown voltage, the power loss in the voltage converter of the switching power supply is substantial due to the characteristics of the inductor. At the instant the transistors in the voltage converter of the switching power supply are turned on or off, the inductor generates a freewheeling current in the circuit, thereby inducing high switching loss. Moreover, the inductor in the voltage converter of the switching power supply has a large equivalent series resistance. This leads to conduction thermal loss when the inductor is operating, and consequently the boost efficiency of the voltage converter of the switching power supply is limited. This prevents the voltage converter of the switching power supply from supplying power to electronic devices with high loads. Furthermore, as the shutdown voltage of a battery with a low shutdown voltage decreases further, the duty cycle of the transistors in the voltage converter of the switching power supply needs to be reduced. In a case where the duty cycle of the transistors in the voltage converter of the switching power supply is reduced, the peak current of the inductor increases accordingly, resulting in higher losses during voltage transmission. Additionally, a reduction in the duty cycle of the transistors in the voltage converter of the switching power supply also necessitates the use of a larger-sized inductor in the voltage converter of the switching power supply, which further increases the loss during the voltage transmission process. SUMMARY The present disclosure provides a switched-capacitor voltage converter, a chip, and an electronic device, to solve the technical problem that the inductor in the switched-capacitor voltage converter induces high loss. In a first aspect, some embodiments of the present disclosure provide a switched-capacitor voltage converter. The switched-capacitor voltage converter includes: a controller, a first transistor, and at least one conversion assembly. A first terminal of the first transistor is electrically connected to the at least one conversion assembly, a second terminal of the first transistor is grounded, and a control terminal of the first transistor is electrically connected to the controller. The switched-capacitor voltage converter includes a first terminal and a second terminal, wherein the at least one conversion assembly is electrically connected between the first terminal and the second terminal of the switched-capacitor voltage converter, each of the at least one conversion assembly includes a capacitor and a plurality of transistors, and the at least one conversion assembly includes a first branch and a second branch, wherein the first branch and the second branch share the capacitor. In a case where the switched-capacitor voltage converter operates in a boost mode: in a first stage, the first branch is in a charging s