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CN-115461974-B - Apparatus and method for controlling charge pump

CN115461974BCN 115461974 BCN115461974 BCN 115461974BCN-115461974-B

Abstract

The invention provides an apparatus and a method for controlling a charge pump. The apparatus for controlling a charge pump includes a charge pump circuit connected to an input circuit, a first capacitor coupled to the charge pump circuit and provided as an element of a resonant circuit, a first switching element connected to the first capacitor, and a controller configured to read an input current and/or an input voltage from the input circuit, generate a pulse width modulation signal according to the input current and/or the input voltage, and output the pulse width modulation signal to control the first switching element. Therefore, THD and harmonics can be improved while reducing the cost of the circuit.

Inventors

  • MAO QIUXIANG
  • LIN SHENGDIE
  • WANG SHUANGHONG

Assignees

  • 赤多尼科两合股份有限公司

Dates

Publication Date
20260508
Application Date
20200529

Claims (13)

  1. 1. An apparatus for controlling a charge pump, comprising: a charge pump circuit connected to the input circuit; A first capacitor coupled to the charge pump circuit and provided as an element of a resonant circuit; A first switching element connected to the first capacitor, wherein a capacitance value of the first capacitor is changed by a switching operation of the first switching element, and A controller configured to read an input current and/or an input voltage from the input circuit, generate a pulse width modulation signal from the input current and/or the input voltage, and output the pulse width modulation signal to control the first switching element, Wherein the controller is configured to modify a charge pump capacitance value of the charge pump circuit during a power frequency period, Wherein the charge pump capacitance value of the charge pump circuit is modified along with the changed capacitance value of the first capacitor, the first capacitor being controlled by the pulse width modulation signal.
  2. 2. The apparatus of claim 1, wherein the controller is configured to adjust the pulse width modulated signal to improve a power factor or a total harmonic distortion or a harmonic of the resonant circuit.
  3. 3. The apparatus of claim 1 or 2, wherein the controller is configured to look up a charge pump capacitance value of the charge pump circuit under one of a plurality of different loads.
  4. 4. The apparatus of claim 3, wherein the controller is configured to change a duty cycle of the pulse width modulated signal to modify the charge pump capacitance in a load, determine whether an input power or the input voltage or input frequency is changed, and maintain the pulse width modulated signal when the input power or the input voltage or the input frequency is unchanged.
  5. 5. The apparatus according to claim 1 or 2, wherein the apparatus further comprises: A second capacitor coupled to the charge pump circuit and provided as an element of the resonant circuit, wherein the second capacitor is connected in parallel with the first capacitor.
  6. 6. The apparatus according to claim 1 or 2, wherein the apparatus further comprises: wherein the pulse width modulation signal from the controller is used to control the second switching element, and the second switching element is configured to generate a signal to control the first switching element.
  7. 7. The device of claim 1 or 2, wherein the resonant circuit is for driving a Light Emitting Diode (LED) as an output load.
  8. 8. A method of controlling a charge pump, wherein a charge pump circuit is connected to an input circuit, a first capacitor is coupled to the charge pump circuit and provided as an element of a resonant circuit, a first switching element is connected to the first capacitor; wherein the method comprises: Reading an input current and/or an input voltage from the input circuit; generating a pulse width modulated signal from said input current and/or said input voltage, and Wherein a capacitance value of the first capacitor is changed by a switching operation of the first switching element, Wherein the method further comprises: Modifying a charge pump capacitance value of the charge pump circuit during a power frequency period, wherein the charge pump capacitance value of the charge pump circuit is modified along with a changed capacitance value of the first capacitor, the first capacitor being controlled by the pulse width modulated signal.
  9. 9. The method of claim 8, wherein the method further comprises: The pulse width modulated signal is adjusted to improve the power factor or the total harmonic distortion or harmonics of the resonant circuit.
  10. 10. The method of claim 8 or 9, wherein the method further comprises: the charge pump capacitance value of the charge pump circuit is looked up under one of a plurality of different loads.
  11. 11. The method of claim 10, wherein the method further comprises: changing the duty cycle of the pwm signal to modify the charge pump capacitance in a load; Determining whether the input power or the input voltage or the input frequency is changed, and The pulse width modulated signal is maintained when the input power or the input voltage or the input frequency is unchanged.
  12. 12. A power driver, comprising: a charge pump circuit connected to the input circuit; A resonant circuit coupled to the charge pump circuit; A switching element connected to a capacitor of the resonant circuit, wherein a capacitance value of the capacitor is changed by a switching operation of the switching element, and A controller configured to read an input current and/or an input voltage from the input circuit, generate a pulse width modulation signal from the input current and/or the input voltage, and output the pulse width modulation signal to control the switching element, Wherein the controller is configured to modify a charge pump capacitance value of the charge pump circuit during a power frequency period, Wherein the charge pump capacitance value of the charge pump circuit is modified along with the changed capacitance value of the capacitor, the capacitor being controlled by the pulse width modulated signal.
  13. 13. The power driver of claim 12, wherein the power driver is for driving a Light Emitting Diode (LED) or the power driver is included in a Light Emitting Diode (LED) driver.

Description

Apparatus and method for controlling charge pump Technical Field Embodiments of the present disclosure relate generally to the field of power control circuits, and more particularly to an apparatus and method of controlling a charge pump. Background Nowadays, more and more resonant circuits are used in power control circuits, e.g. single-stage LLC circuits are commonly used for low output ripple currents and low cost products. Meanwhile, a charge pump circuit is generally applied to a power control circuit. For example, in some solutions series charge pump capacitors are added to improve THD (total harmonic distortion) and/or harmonics. Reference 1 WO2013/113836A1. Reference 2 us2009/0128057A1. Reference 3, us6366027b1. This section presents a simplified summary that may facilitate a better understanding of aspects of the disclosure. Accordingly, the statements of this section are to be read in this light, and not as admissions of prior art. Disclosure of Invention The inventors have found that the addition of a series charge pump capacitor is required to improve THD and harmonics for widening voltage products such as Light Emitting Diodes (LEDs). In this solution, the charge pump capacitance is constant with a certain load for each of the loads, so it is a high cost solution. In some solutions, a first order Power Factor Correction (PFC) function may be added for different loads, however the cost of the PFC function is also high. Furthermore, these solutions are time consuming during development and poor performance of the harmonics will limit the operating range. To address at least some of the above issues, methods, apparatus, and devices are provided in the present disclosure. Features and advantages of embodiments of the present disclosure will also be apparent from the following description of the particular embodiments, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the embodiments of the disclosure. In general, embodiments of the present disclosure provide an apparatus and method for controlling a charge pump. It is desirable to reduce the number of parts and cost while improving THD and/or harmonics with a simple structure. In a first aspect, an apparatus for controlling a charge pump is provided. The apparatus for controlling a charge pump includes a charge pump circuit connected to an input circuit and an output circuit, a first capacitor coupled to the charge pump circuit and provided as an element of a resonant circuit, a first switching element connected to the first capacitor, wherein a capacitance value of the first capacitor is changed by a switching operation of the first switching element, and a controller configured to read an input current and/or an input voltage from the input circuit, generate a pulse width modulation signal according to the input current and/or the input voltage, and output the pulse width modulation signal to control the first switching element. In some embodiments, the controller is configured to adjust the pulse width modulated signal to improve the power factor or the total harmonic distortion or harmonics of the resonant circuit. In some embodiments, the controller is configured to modify a charge pump capacitance value of the charge pump circuit during a power frequency period. In some embodiments, the charge pump capacitance value of the charge pump circuit is modified along with the changed capacitance value of the first capacitor, which is controlled by the pulse width modulated signal. In some embodiments, the controller is configured to look up the charge pump capacitance value of the charge pump circuit under one of a plurality of different loads. In some embodiments, the controller is configured to change the duty cycle of the pulse width modulated signal to modify the charge pump capacitance in a load, determine whether the input power or input voltage or input frequency is changed, and maintain the pulse width modulated signal when the input power or input voltage or input frequency is unchanged. In some embodiments, the apparatus further comprises a second capacitor coupled to the charge pump circuit and provided as an element of the resonant circuit, wherein the second capacitor is connected in parallel with the first capacitor. In some embodiments, the apparatus further comprises a second switching element configured between the first switching element and the controller, wherein the pulse width modulated signal from the controller is used to control the second switching element, and the second switching element is configured to generate a signal to control the first switching element. In a second aspect, a method of controlling a charge pump is provided, wherein a charge pump circuit is connected to an input circuit and an output circuit; The method includes reading an input current and/or an input voltage from an input circuit, generating a pulse width modulation signal according to the