Charge pump circuit

Abstract

This application discloses a charge pump circuit, which includes: a first capacitor; a switch control unit that receives a first voltage, a second voltage, and a third voltage, and controls the first voltage to be applied to charge the first capacitor in the first stage of a boost cycle, and switches the application of the second voltage or the third voltage to discharge the first capacitor at a predetermined ratio in the second stage of the boost cycle to generate an output voltage; and a second capacitor connected between the output voltage and ground, wherein the boost cycle includes multiple alternating first and second stages. This application can avoid the power consumption caused by excessive output capability due to a limited fixed boost ratio, thus achieving a power-saving effect.

Description

Technical Field

[0001] This application relates to the field of electronic power technology, specifically to a charge pump circuit. Background Technology

[0002] With the advent of the era of electrification and intelligence, electronic devices have increasingly diverse requirements for power supply voltage. As the main circuit for voltage boosting and cooling, charge pumps are widely used in various scenarios requiring different output voltages.

[0003] A charge pump, also known as a switched-load capacitor voltage converter, is a converter that uses a load capacitor to store energy, either "fastly" or "pumping". Existing charge pump circuits have the following problems: Generally, charge pump circuits obtain the target output voltage based on a preset boost ratio. However, when the target output voltage is higher than the actual required voltage, it results in wasted power.

[0004] Therefore, there is an urgent need to develop a new type of charge pump circuit to overcome the shortcomings of existing technologies. Utility Model Content

[0005] To address the aforementioned technical problems, this application provides a charge pump circuit that is not limited by a fixed boost rate and achieves energy-saving effects.

[0006] According to one aspect of this application, a charge pump circuit is provided, comprising:

[0007] First capacitor;

[0008] A switch control unit receives a first voltage, a second voltage, and a third voltage, and controls the application of the first voltage to charge the first capacitor during the first stage of a boost cycle, and switches the application of the second voltage or the third voltage to discharge the first capacitor at a predetermined ratio during the second stage of the boost cycle, thereby generating an output voltage; and

[0009] The second capacitor is connected between the output voltage and ground.

[0010] The boost cycle includes multiple alternating first and second stages.

[0011] Optionally, the output voltage is: Wherein, Vout is the output voltage, Vp1 is the first voltage, Vp2 is the second voltage, Vp3 is the third voltage, and D is the predetermined ratio.

[0012] Optionally, in one of the two adjacent second stages, the second voltage is applied to discharge the first capacitor, and in the other second stage, the third voltage is applied to discharge the first capacitor.

[0013] Optionally, the ratio of the duration of each of two adjacent second stages is obtained according to the predetermined ratio.

[0014] Optionally, in each second stage, the first capacitor is discharged by switching between the second voltage and the third voltage at a predetermined ratio, wherein the ratio of the duration of the second voltage to the duration of the third voltage in each second stage is obtained according to the predetermined ratio.

[0015] Optionally, the switch control unit includes:

[0016] A first switch, wherein a first terminal of the first switch receives the first voltage, and a second terminal of the first switch is connected to a first terminal of the first capacitor;

[0017] A second switch, the first end of which is connected to the second end of the first capacitor, and the second end of which receives a reference low voltage;

[0018] In the first stage, the control unit controls the first switch and the second switch to be turned on, forming a charging circuit with the first capacitor, and applies the first voltage to charge the first capacitor.

[0019] Optionally, the switch control unit further includes:

[0020] A third switch, wherein the first end of the third switch is connected to the first end of the first capacitor, the second end of the third switch is connected to the first end of the second capacitor and outputs the output voltage, and the second end of the second capacitor is grounded;

[0021] A fourth switch, wherein a first terminal of the fourth switch receives the second voltage, and a second terminal of the fourth switch is connected to the second terminal of the first capacitor; and

[0022] A fifth switch, wherein the first terminal of the fifth switch receives the third voltage, and the second terminal of the fifth switch is connected to the second terminal of the first capacitor.

[0023] In the first stage, the control unit controls the third switch, the fourth switch, and the fifth switch to turn off;

[0024] In the second stage, the control unit also controls the first and second switches to turn off, controls the third switch to turn on, and controls the fourth switch to turn on and form a discharge circuit with the first capacitor, and connects the second voltage to discharge the first capacitor, or controls the fifth switch to turn on and form a discharge circuit with the first capacitor, and connects the third voltage to discharge the first capacitor.

[0025] The charge pump circuit provided in this application charges a first capacitor by applying a first voltage in the first stage of the boost cycle, and discharges the first capacitor by switching between applying a second voltage or a third voltage at a predetermined ratio in the second stage of the boost cycle, thereby generating a weighted average output voltage. This avoids excessive power consumption caused by a limited fixed boost ratio leading to excessive output capacity, thus achieving power saving.

[0026] It should be noted that the above general description and the following detailed description are merely exemplary and explanatory, and do not limit this application. Attached Figure Description

[0027] Figure 1 A schematic diagram of a charge pump circuit according to an embodiment of this application is shown;

[0028] Figure 2 A waveform diagram of a charge pump circuit according to an embodiment of this application is shown;

[0029] Figure 3 A waveform diagram of another charge pump circuit provided according to an embodiment of this application is shown;

[0030] Figure 4 A schematic diagram of a charge pump circuit according to an embodiment of this application is shown in the first stage;

[0031] Figure 5 A schematic diagram of a charge pump circuit according to an embodiment of this application is shown in the second stage;

[0032] Figure 6 A schematic diagram of another charge pump circuit provided according to an embodiment of this application is shown in the second stage. Detailed Implementation

[0033] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application may be implemented in various forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0034] Figure 1 A schematic diagram of a charge pump circuit according to an embodiment of this application is shown. Figure 2 The diagram shows a waveform of a charge pump circuit according to an embodiment of this application. Figure 3 A waveform diagram of another charge pump circuit provided according to an embodiment of this application is shown. Figure 4 A schematic diagram of a charge pump circuit provided according to an embodiment of this application is shown in the first stage. Figure 5A schematic diagram of a charge pump circuit provided according to an embodiment of this application is shown in the second stage. Figure 6 A schematic diagram of another charge pump circuit provided according to an embodiment of this application is shown in the second stage.

[0035] like Figure 1 As shown in the figure, a charge pump circuit 100 provided in this application embodiment includes a first capacitor C1, a switch control unit 110, and a second capacitor C2.

[0036] The switch control unit 110 receives a first voltage Vp1, a second voltage Vp2, and a third voltage Vp3, and controls the first voltage Vp1 to charge the first capacitor C1 during the first stage T1 of the boost cycle. During the second stage T2 of the boost cycle, the second voltage Vp2 or the third voltage Vp3 is switched at a predetermined ratio D to discharge the first capacitor C1, thereby generating an output voltage Vout. A second capacitor C2 is connected between the output voltage Vout and ground VSSA. The output voltage... Vout is the output voltage, Vp1 is the first voltage, Vp2 is the second voltage, Vp3 is the third voltage, and D is the predetermined ratio.

[0037] For example, the switch control unit 110 includes a first switch s1, a second switch s2, a control unit 120, a third switch s3, a fourth switch s4, and a fifth switch s5.

[0038] The first terminal of the first switch s1 receives the first voltage Vp1, and the second terminal of the first switch s1 is connected to the first terminal C1P of the first capacitor C1.

[0039] The first terminal of the second switch s2 is connected to the second terminal C1N of the first capacitor C1, and the second terminal of the second switch s2 receives the reference low voltage VSSP.

[0040] The first terminal of the third switch s3 is connected to the first terminal C1P of the first capacitor C1, the second terminal of the third switch s3 is connected to the first terminal of the second capacitor C2 and outputs the output voltage Vout, and the second terminal of the second capacitor C2 is grounded VSSA.

[0041] The first terminal of the fourth switch s4 receives the second voltage Vp2, and the second terminal of the fourth switch s4 is connected to the second terminal C1N of the first capacitor C1.

[0042] The first terminal of the fifth switch s5 receives the third voltage Vp3, and the second terminal of the fifth switch s5 is connected to the second terminal C1N of the first capacitor C1.

[0043] In the first stage T1, the control unit 120 controls the first switch s1 and the second switch s2 to be turned on, forming a charging circuit with the first capacitor C1, and applies the first voltage Vp1 to charge the first capacitor C1. It also controls the third switch s3, the fourth switch s4, and the fifth switch s5 to be turned off.

[0044] In the second stage T2, the control unit 120 also controls the first switch s1 and the second switch s2 to turn off, and controls the third switch s3 to turn on. It also controls the fourth switch s4 to turn on and form a discharge circuit with the first capacitor C1, applying the second voltage Vp2 to discharge the first capacitor C1; or it controls the fifth switch s5 to turn on and form a discharge circuit with the first capacitor C1, applying the third voltage Vp3 to discharge the first capacitor C1.

[0045] For example, the control unit 120 generates a first control signal g1, a second control signal g2, a third control signal g3, a fourth control signal g4, ​​and a fifth control signal g5, and provides the first control signal g1 to the control terminal of the first switch s1, the second control signal g2 to the control terminal of the second switch s2, the third control signal g3 to the control terminal of the third switch s3, the fourth control signal g4 to the control terminal of the fourth switch s4, and the fifth control signal g5 to the control terminal of the fifth switch s5. This controls the formation of a charging circuit in the first stage and a discharging circuit in the second stage.

[0046] For example, such as Figure 2 As shown, the boost cycle includes multiple alternating first stages T1 and second stages T2. Further, a second voltage Vp2 and a third voltage Vp3 are alternately applied in the multiple second stages T2 according to a predetermined ratio D. Specifically, for example, in one of two adjacent second stages T2, the second voltage Vp2 is applied to discharge the first capacitor C1, and in the other second stage T2, the third voltage Vp3 is applied to discharge the first capacitor C1.

[0047] Furthermore, the ratio of the duration of each of the two adjacent second stages T2 is obtained according to a predetermined ratio D.

[0048] For example, such as Figure 3 As shown, the boost cycle includes multiple alternating first stages T1 and second stages T2. Further, in each second stage T2, a second voltage Vp2 and a third voltage Vp3 are alternately applied according to a predetermined ratio D. Specifically, for example, the second voltage Vp2 is applied at a first time in each second stage T2 to discharge the first capacitor C1, and the third voltage Vp3 is applied at a second time in each second stage T2 to discharge the first capacitor C1.

[0049] Furthermore, in each second stage T2, the ratio of the duration of the second voltage Vp2 (first time) to the duration of the third voltage Vp3 (second time) is obtained according to a predetermined ratio D.

[0050] It should be noted that in other embodiments, for example, a second voltage Vp2 can be applied to discharge the first capacitor C1 in a second stage T2 of a portion of the boost cycle, and a third voltage Vp3 can be applied to discharge the first capacitor C1 in another second stage T2 of the boost cycle, so as to achieve a predetermined ratio.

[0051] In other embodiments, at least two of the above three embodiments may be combined to achieve a predetermined ratio.

[0052] Furthermore, the above embodiments can be selected according to the output ripple requirements to achieve a predetermined ratio.

[0053] In the first stage, a charging circuit A1 is formed to store energy in the first capacitor C1. Specifically, as follows: Figure 4 As shown, in the first stage T1, the control unit 120 provides a first control signal g1 and a second control signal g2 to turn on the first switch s1 and the second switch s2, and controls the third switch s3, the fourth switch s4, and the fifth switch s5 to turn off. The first voltage Vp1 charges the first capacitor C1 through the charging circuit A1.

[0054] In the second stage, a discharge circuit is formed to discharge the first capacitor C1 and achieve voltage boost.

[0055] Specifically, in the second stage, the discharge circuit A21 that discharges the first capacitor C1 by connecting the second voltage Vp2 is as follows: Figure 5 As shown. The third control signal g3 and the fourth control signal g4 provided by the control unit 120 turn on the third switch s3 and the fourth switch s4, and turn off the first switch s1, the second switch s2, and the fifth switch s5. The second voltage Vp2 discharges through the discharge circuit A21 to the first capacitor C1 to achieve voltage boost.

[0056] Specifically, in the second stage, the discharge circuit A22 that discharges the first capacitor C1 by connecting the third voltage Vp3 is as follows: Figure 6 As shown. The third control signal g3 and the fifth control signal g5 provided by the control unit 120 turn on the third switch s3 and the fifth switch s5, and turn off the first switch s1, the second switch s2, and the fourth switch s4. The third voltage Vp3 discharges through the discharge circuit A22 to discharge the first capacitor C1, thereby achieving a voltage boost.

[0057] Furthermore, let's take D as an example of 0.5. Figure 2Taking the illustrated embodiment as an example, the ratio of the duration of the second stage T2 when the second voltage Vp2 is applied to the duration of the second stage T2 when the third voltage Vp3 is applied to the duration of the second stage T2 is 1:1. That is, the ratio of the duration of the fourth switch s4 being on to the duration of the fifth switch s5 being on in the second stage is 1:1. Further, taking D as 0.25 as an example, the ratio of the duration of the second stage T2 when the second voltage Vp2 is applied to the duration of the second stage T2 when the third voltage Vp3 is applied to the duration of the second stage T2 is 1:3. That is, the ratio of the duration of the fourth switch s4 being on to the duration of the fifth switch s5 being on in the second stage is 1:3.

[0058] Furthermore, let's take D as an example of 0.5. Figure 3 Taking the illustrated embodiment as an example, the ratio of the duration of the second voltage Vp2 to the duration of the third voltage Vp3 in each second stage T2 is 1:1. That is, the ratio of the duration of the fourth switch s4 being on to the duration of the fifth switch s5 being on in each second stage T2 is 1:1. Further, taking D as 0.25 as an example, the ratio of the duration of the second voltage Vp2 to the duration of the third voltage Vp3 in each second stage T2 is 1:3. That is, the ratio of the duration of the fourth switch s4 being on to the duration of the fifth switch s5 being on in each second stage T2 is 1:3.

[0059] It should be noted that the implementation of this application is not limited to this, and D can be any value in (0, 1).

[0060] Furthermore, the load current Iout provided at the output of the charge pump circuit is supplied by a first voltage source (providing a first voltage Vp1), a second voltage source (providing a second voltage Vp2), and a third voltage source (providing a third voltage Vp3). For example, the load current... Wherein, current I1 is the current provided by the first voltage source, current I2 is the current provided by the second voltage source, and current I3 is the current provided by the third voltage source.

[0061] The charge pump circuit of this application, when the output voltage is insufficient to meet the supply voltage required by the load, switches between a second voltage and a third voltage at a predetermined ratio during the second stage of the boost cycle to generate a weighted average output voltage. This avoids excessive power consumption caused by a limited fixed boost ratio leading to excessive output capacity, thus achieving power saving.

[0062] It should be noted that the charge pump circuit provided in this application can achieve both positive and negative voltage boosting.

[0063] This application also provides a control method for a charge pump circuit, comprising: charging a first capacitor by applying a first voltage in a first stage of a boost cycle; and discharging the first capacitor by switching between applying a second voltage or a third voltage at a predetermined ratio in a second stage of the boost cycle to generate an output voltage, wherein the boost cycle includes multiple alternating first and second stages.

[0064] Furthermore, the output voltage is: Where Vout is the output voltage, Vp1 is the first voltage, Vp2 is the second voltage, Vp3 is the third voltage, and D is a predetermined ratio.

[0065] Furthermore, in one of the two adjacent second stages, a second voltage is applied to discharge the first capacitor, and in the other second stage, a third voltage is applied to discharge the first capacitor.

[0066] Furthermore, the ratio of the duration of each of the two adjacent second stages is obtained according to a predetermined ratio.

[0067] Furthermore, in each second stage, the first capacitor is discharged by switching between the second voltage and the third voltage at a predetermined ratio, wherein the ratio of the duration of the second voltage to the duration of the third voltage in each second stage is obtained according to the predetermined ratio.

[0068] The charge pump circuit provided in this application charges a first capacitor by applying a first voltage in the first stage of the boost cycle, and discharges the first capacitor by switching between applying a second voltage or a third voltage at a predetermined ratio in the second stage of the boost cycle, thereby generating a weighted average output voltage. This avoids excessive power consumption caused by a limited fixed boost ratio leading to excessive output capacity, thus achieving power saving.

[0069] It should be noted that the numerical values ​​in this article are for illustrative purposes only. In other embodiments of this application, other numerical values ​​may be sampled to implement this solution. The specific values ​​should be reasonably set according to the current situation, and this application does not limit them.

[0070] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating this application and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

[0071] It should also be understood that the terminology and expressions used herein are for descriptive purposes only, and one or more embodiments described herein should not be limited to these terms and expressions. The use of these terms and expressions does not exclude any illustrative and descriptive equivalent features (or parts thereof), and it should be recognized that various modifications that may exist should also be included within the scope of the claims. Other modifications, variations, and substitutions may also exist. Accordingly, the claims should be considered to cover all such equivalents.

Claims

1. A charge pump circuit, characterized in that, include: First capacitor; The switch control unit receives a first voltage, a second voltage, and a third voltage, and controls the first voltage to be applied to charge the first capacitor in the first stage of the boost cycle, and switches the second voltage or the third voltage to be applied to discharge the first capacitor in a predetermined ratio in the second stage of the boost cycle to generate an output voltage. as well as The second capacitor is connected between the output voltage and ground. The boost cycle includes multiple alternating first and second stages.

2. The charge pump circuit according to claim 1, characterized in that, The output voltage is: Wherein, Vout is the output voltage, Vp1 is the first voltage, Vp2 is the second voltage, Vp3 is the third voltage, and D is the predetermined ratio.

3. The charge pump circuit according to claim 1, characterized in that, In one of two adjacent second stages, the second voltage is applied to discharge the first capacitor, and in the other second stage, the third voltage is applied to discharge the first capacitor. The ratio of the duration of each of two adjacent second stages is obtained according to the predetermined ratio.

4. The charge pump circuit according to claim 1, characterized in that, In each of the second stages, the first capacitor is discharged by switching the second voltage and the third voltage at a predetermined ratio. The ratio of the duration of the second voltage to the duration of the third voltage in each second stage is obtained according to the predetermined ratio.

5. The charge pump circuit according to claim 1, characterized in that, The switch control unit includes: A first switch, wherein a first terminal of the first switch receives the first voltage, and a second terminal of the first switch is connected to a first terminal of the first capacitor; A second switch, the first end of which is connected to the second end of the first capacitor, and the second end of which receives a reference low voltage; In the first stage, the control unit controls the first switch and the second switch to be turned on, forming a charging circuit with the first capacitor, and applies the first voltage to charge the first capacitor.

6. The charge pump circuit according to claim 3 or 4, characterized in that, The switch control unit further includes: A third switch, wherein the first terminal of the third switch is connected to the first terminal of the first capacitor, the second terminal of the third switch is connected to the first terminal of the second capacitor and outputs the output voltage, and the second terminal of the second capacitor is grounded; A fourth switch, wherein a first terminal of the fourth switch receives the second voltage, and a second terminal of the fourth switch is connected to the second terminal of the first capacitor; and A fifth switch, wherein the first terminal of the fifth switch receives the third voltage, and the second terminal of the fifth switch is connected to the second terminal of the first capacitor. In the first stage, the control unit controls the third switch, the fourth switch, and the fifth switch to turn off; In the second stage, the control unit also controls the first and second switches to turn off, and controls the third switch to turn on. And control the fourth switch to be turned on and form a discharge circuit with the first capacitor, and apply the second voltage to discharge the first capacitor, or control the fifth switch to be turned on and form a discharge circuit with the first capacitor, and apply the third voltage to discharge the first capacitor, or control the fourth switch to be turned on and form a discharge circuit with the first capacitor according to a predetermined ratio, and apply the second voltage to discharge the first capacitor, and control the fifth switch to be turned on and form a discharge circuit with the first capacitor, and apply the third voltage to discharge the first capacitor.

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