A high-energy-efficiency charge pump circuit and its control method

Abstract

The present invention belongs to the technical field of integrated circuits, and particularly relates to an energy-efficient charge pump circuit and its control method. Among them, the energy-efficient charge pump circuit includes: a first transistor, whose gate is connected to a second control signal and whose source is connected to a power supply potential; a second transistor, whose gate is connected to a first control signal; a first capacitor, whose upper plate is connected to the drain of the first transistor and the source of the second transistor, and whose lower plate is connected to a ground potential; a third transistor, whose gate is connected to the second control signal; a second capacitor, whose upper plate is connected to the drain of the second transistor and the drain of the third transistor and serves as an output terminal, and whose lower plate is connected to the ground potential; a fourth transistor, whose gate is connected to the first control signal and whose source is connected to the ground potential; a third capacitor, whose upper plate is connected to the source of the third transistor and the drain of the fourth transistor, and whose lower plate is connected to the ground potential. In the present invention, the overdrive voltages of the second transistor and the third transistor are both reduced, greatly improving the energy efficiency of the charge pump circuit.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated circuits, and particularly relates to a charge pump circuit and a control method thereof. Background Art

[0002] As is well known, a charge pump circuit is one of the core circuit units of a phase-locked loop, and charge pump circuits have been widely used in the past in applications such as relaxation oscillators and comparator calibration. With the development of portable electronic devices, charge pumps have stood out in analog integrated circuit applications due to their lack of inductors and ease of integration. Since portable electronic devices generally use batteries for power supply, this requires charge pumps to have high energy efficiency in order to meet the long battery life requirements of daily life. In recent years, a large number of scholars at home and abroad have done a lot of research work on energy-efficient charge pump circuits, striving to develop the energy efficiency of charge pumps to a new level. Summary of the Invention

[0003] Aiming at the technical problem in the prior art that there is a lack of a high-energy-efficiency charge pump circuit, the purpose of the present invention is to provide a high-energy-efficiency charge pump circuit and a control method thereof.

[0004] A high-energy-efficiency charge pump circuit includes:

[0005] Two input control signals, namely a first control signal and a second control signal;

[0006] A first transistor, whose gate is connected to the second control signal and whose source is connected to the power supply potential;

[0007] A second transistor, whose gate is connected to the first control signal;

[0008] A first capacitor, whose upper plate is respectively connected to the drain of the first transistor and the source of the second transistor, and whose lower plate is connected to the ground potential;

[0009] A third transistor, whose gate is connected to the second control signal;

[0010] A second capacitor, whose upper plate is respectively connected to the drain of the second transistor and the drain of the third transistor and serves as the output terminal of the charge pump circuit, and whose lower plate is connected to the ground potential;

[0011] A fourth transistor, whose gate is connected to the first control signal and whose source is connected to the ground potential;

[0012] A third capacitor, whose upper plate is respectively connected to the source of the third transistor and the drain of the fourth transistor, and whose lower plate is connected to the ground potential.

[0013] As a preferred solution, the first transistor and the second transistor are N-channel insulated gate bipolar transistors.

[0014] As a preferred solution, the third transistor and the fourth transistor are P-channel insulated gate bipolar transistors.

[0015] A control method for an energy-efficient charge pump circuit includes:

[0016] Controlling the first control signal to be at a high level and the second control signal to be at a low level, then the charge pump circuit is in a discharging state, and the potential of the output terminal of the charge pump circuit continuously decreases until the third transistor is turned off, and the discharging state ends;

[0017] Controlling the first control signal to be at a low level and the second control signal to be at a high level, then the charge pump circuit is in a charging state, and the potential of the output terminal of the charge pump circuit continuously increases until the second transistor is turned off, and the charging state ends.

[0018] The positive and progressive effects of the present invention are as follows: The present invention adopts an energy-efficient charge pump circuit and its control method, which can achieve two working states of charging and discharging. Due to the presence of the first capacitor and the second capacitor, the overdrive voltages of the second transistor in the charging state and the third transistor in the discharging state are both reduced, greatly improving the energy efficiency of the charge pump circuit. The present invention has a relatively broad application prospect in the design of energy-efficient charge pump circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a circuit diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below with reference to specific drawings.

[0021] Refer to Figure 1 , an energy-efficient charge pump circuit includes a first control signal A, a second control signal B, a first transistor M1, a second transistor M2, a third transistor M3, a fourth transistor M4, a first capacitor C1, a second capacitor C2, and a third capacitor C3.

[0022] The gates of the first transistor M1 and the third transistor M3 are both connected to the second control signal B. The source of the first transistor M1 is connected to the power supply potential. The drain of the first transistor M1 and the source of the second transistor M2 are both connected to the upper plate of the first capacitor C1, and the lower plate of the first capacitor C1 is connected to the ground potential.

[0023] The gates of the second transistor M2 and the fourth transistor M4 are both connected to the first control signal A. The drains of the second transistor M2 and the third transistor M3 are both connected to the upper plate of the second capacitor C2 and serve as the output terminal OUT of the charge pump circuit. The lower plate of the second capacitor C2 is connected to the ground potential. The source of the third transistor M3 and the drain of the fourth transistor M4 are both connected to the upper plate of the third capacitor C3. The lower plate of the third capacitor C3 is connected to the ground potential. The source of the fourth transistor M4 is connected to the ground potential.

[0024] In some embodiments, the first transistor M1 and the second transistor M2 are N-channel insulated gate bipolar transistors.

[0025] In some embodiments, the third transistor M3 and the fourth transistor M4 are P-channel insulated gate bipolar transistors.

[0026] The charge pump circuit of the present invention has two operating modes: charging and discharging. When the first control signal A is at a high level and the second control signal B is at a low level, the charge pump circuit is in a discharging state. When the first control signal A is at a low level and the second control signal B is at a high level, the charge pump circuit is in a charging state.

[0027] When the first control signal A is at a high level and the second control signal B is at a low level, the charge pump circuit is in a discharging state. The first transistor M1 is turned on and the second transistor M2 is turned off. The first capacitor C1 is charged to the power supply potential. The third transistor M3 is turned on and the fourth transistor M4 is turned off. The potential of the output terminal OUT of the charge pump circuit continuously decreases due to the existence of the pull-down current. At the same time, the potential of the upper plate of the third capacitor C3 continuously increases until the third transistor M3 is turned off. During the discharging process, since the source potential of the third transistor M3 gradually rises, the overdrive voltage of the third transistor M3 gradually decreases with the discharging process, which improves the energy efficiency of the charge pump circuit in the charging state.

[0028] When the first control signal A is at a low level and the second control signal B is at a high level, the charge pump circuit is in a charging state. The third transistor M3 is turned off and the fourth transistor M4 is turned on. The voltage on the third capacitor C3 is reset to near the ground potential. The first transistor M1 is turned off and the second transistor M2 is turned on. The first capacitor C1 starts to charge the second capacitor C2, and the voltage of the upper plate of the first capacitor C1 starts to drop from the power supply voltage. The potential of the output terminal OUT of the charge pump circuit continuously increases due to the existence of the pull-up current. At the same time, when the potential of the upper plate of the first capacitor C1 drops to the point where the second transistor M2 is turned off, the charging state ends. During the charging process, since the source potential of the second transistor M2 continuously drops, the overdrive voltage of the second transistor M2 gradually decreases with the discharging process, which improves the energy efficiency of the charge pump circuit in the discharging state.

[0029] The present invention also provides a control method for controlling the charge pump circuit of the present invention, including:

[0030] Controlling the first control signal A to be at a high level and the second control signal B to be at a low level, then the charge pump circuit is in a discharging state, and the potential of the output terminal of the charge pump circuit continuously decreases until the third transistor M3 is turned off, and the discharging state ends;

[0031] Controlling the first control signal A to be at a low level and the second control signal B to be at a high level, then the charge pump circuit is in a charging state, and the potential of the output terminal of the charge pump circuit continuously increases until the second transistor M2 is turned off, and the charging state ends.

[0032] By introducing the existence of the first capacitor C1 and the second capacitor C2, the present invention reduces the overdrive voltages of the second transistor M2 in the charging state and the third transistor M3 in the discharging state of the charge pump circuit, and greatly improves the energy efficiency of the charge pump circuit.

[0033] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A high - efficiency charge pump circuit, characterized in that, Including: Two input control signals, namely a first control signal and a second control signal respectively; A first transistor, with its gate connected to the second control signal and its source connected to the power supply potential; A second transistor, with its gate connected to the first control signal; A first capacitor, with its upper plate connected to the drain of the first transistor and the source of the second transistor respectively, and its lower plate connected to the ground potential; A third transistor, with its gate connected to the second control signal; A second capacitor, with its upper plate connected to the drain of the second transistor and the drain of the third transistor respectively and serving as the output terminal of the charge pump circuit, and its lower plate connected to the ground potential; A fourth transistor, with its gate connected to the first control signal and its source connected to the ground potential; A third capacitor, with its upper plate connected to the source of the third transistor and the drain of the fourth transistor respectively, and its lower plate connected to the ground potential.

2. The high energy efficiency charge pump circuit according to claim 1, wherein The first transistor and the second transistor are N-channel insulated gate bipolar transistors.

3. The high-efficiency charge pump circuit according to claim 1 or 2, characterized in that The third transistor and the fourth transistor are P-channel insulated gate bipolar transistors.

4. A control method for controlling the high-efficiency charge pump circuit according to any one of claims 1 to 3, characterized in that, Including: When the first control signal is controlled to be at a high level and the second control signal is at a low level, the charge pump circuit is in a discharging state, and the potential of the output terminal of the charge pump circuit continuously decreases until the third transistor is turned off, and the discharging state ends; When the first control signal is controlled to be at a low level and the second control signal is at a high level, the charge pump circuit is in a charging state, and the potential of the output terminal of the charge pump circuit continuously increases until the second transistor is turned off, and the charging state ends.

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