Hybrid switched mode power supply converter and control method

Abstract

This invention relates to the field of switching power supply technology, and discloses a hybrid switching power supply converter and control method, including eight switching devices S1-S8 and two energy storage capacitors C. F1 and C F2 One inductor L; the source of S1 is electrically connected to the input voltage V. IN The drain of S1 is electrically connected to one end of inductor L and the drain of S2, respectively; the source of S2 is electrically connected to ground; the source of S3 is electrically connected to the other end of inductor L and the energy storage capacitor C, respectively. F1 The upper plate of S3 is electrically connected, and the drain of S3 is connected to the energy storage capacitor C. F2 The upper plate of S4, the drain of S4, and the drain of S6 are electrically connected; the source of S4 is connected to the energy storage capacitor C. F1 The lower plate of S5 is electrically connected to the drain of S5; the source of S5 is connected to ground; the source of S6 is electrically connected to the source of S7; the drain of S7 is connected to the energy storage capacitor C. F2 The lower plate of S8 is electrically connected to the drain of S8; the source of S8 is connected to ground. This invention reduces the losses of the switch and inductor, improves operating efficiency, and meets the needs of low-power application scenarios.

Description

Technical Field

[0001] This invention relates to the field of switching power supply technology, and more specifically, to a hybrid switching power supply converter and its control method. Background Technology

[0002] Today, compact electronic devices are widely used in all aspects of life. As their size decreases, their operating voltage will also continue to decrease. Therefore, a DC-DC buck converter with a low voltage conversion ratio is needed to convert the lithium battery voltage of about 4.2-2.8V to a supply voltage of 1V or even lower. In addition, the size of inductors will gradually shrink, but their DC on-resistance (DCR) will still be very large, which will lead to significant heat loss and affect the operating efficiency and service life of the device.

[0003] like Figure 7 As shown, traditional buck converters have advantages such as simple structure and stable performance, and are therefore widely used. However, their average inductor current is equal to the load current, so the DCR loss of the inductor will be very large under heavy load conditions, resulting in severe heat generation; the conduction loss of the switching transistor will also increase, deteriorating the efficiency of the entire system. In addition, the voltage conversion ratio range of the traditional structure is 0-1, which is consistent with the switch duty cycle signal. When converting to a relatively low voltage, the switch duty cycle signal becomes very narrow, which may cause the circuit to be unable to easily complete a large voltage reduction conversion.

[0004] To address the problems inherent in traditional structures, numerous scholars have conducted extensive research and exploration into the topologies of buck converters in recent years. Most new topologies utilize hybrid structures combining flying capacitors and inductors to improve circuit performance. For example... Figure 8 As shown, the most effective one is the capacitor-inductor series-buck converter (CPL-Buck Converter) proposed by Guigang Cai et al. in 2022. It consists of 6 switches and 2 flying capacitors, and its voltage conversion ratio (denoted as M) is as follows:

[0005]

[0006] Where D is the duty cycle, representing the on-time of the switching transistor. M ranges from 0 to 1 / 3, meaning this converter can easily convert the original supply voltage to a significantly lower voltage. Based on the load capacitance C... L The average inductor current I can be calculated from the charge-discharge balance. L for:

[0007]

[0008] Compared to traditional structures, its average inductor current is significantly reduced, and can be further reduced as the conversion ratio increases.

[0009] However, existing technologies still suffer from problems such as excessive average inductance current, high losses, and low efficiency. Therefore, how to invent a hybrid switching power supply converter with low average inductance current, low losses, and high efficiency is an urgent problem to be solved in this technical field. Summary of the Invention

[0010] This invention proposes a hybrid switching power supply converter and its control method. This invention reduces switching and inductor losses, improves operating efficiency, and simultaneously achieves a significant step-down conversion, meeting the needs of low-power applications.

[0011] To achieve the above-mentioned objectives of this invention, the technical solution adopted is as follows:

[0012] A hybrid switching power supply converter includes eight switching devices S1-S8 and two energy storage capacitors C. F1 and C F2 1 inductor L;

[0013] S1 source electrical connection input voltage V IN The drain of S1 is electrically connected to one end of inductor L and the drain of S2, respectively; the source of S2 is electrically connected to ground; the source of S3 is electrically connected to the other end of inductor L and the energy storage capacitor C, respectively. F1 The upper plate of S3 is electrically connected, and the drain of S3 is connected to the energy storage capacitor C. F2 The upper plate of S4, the drain of S4, and the drain of S6 are electrically connected; the source of S4 is connected to the energy storage capacitor C. F1 The lower plate of S5 is electrically connected to the drain of S5; the source of S5 is connected to ground; the source of S6 is electrically connected to the source of S7; the drain of S7 is connected to the energy storage capacitor C. F2 The lower plate of S6 is electrically connected to the drain of S8; the source of S8 is connected to ground; the voltage between the sources of S6 and S7 is called the output voltage V. O .

[0014] Preferably, it also includes a load capacitor C. L C L The upper plates are electrically connected to the source electrodes of S6 and S7, respectively; C L The lower electrode is connected to ground level.

[0015] Furthermore, S1, S3, S4, S6, and S7 are all PMOS transistors.

[0016] Furthermore, S2, S5, and S8 are all NMOS transistors.

[0017] Furthermore, the sources of S6 and S7 are also electrically connected to the current detection device.

[0018] Furthermore, the sources of S6 and S7 are also electrically connected to the voltage detection device.

[0019] A control method for a hybrid switching power supply converter:

[0020] When the duty cycle of the switching signal of the hybrid switching power supply converter is the set threshold D, the control switching devices S2, S3, S5, and S7 are turned off; S1, S4, S6, and S8 are turned on.

[0021] The control signal levels corresponding to S2, S3, S5, and S7 are low, high, low, and high, respectively; the control signal levels corresponding to S1, S4, S6, and S8 are low, low, low, and high, respectively.

[0022] A control method for a hybrid switching power supply converter:

[0023] When the duty cycle of the switching signal of the hybrid switching power supply converter is the set threshold 1-D, the control switching devices S1, S4, S6, and S8 are turned off; S2, S3, S5, and S7 are turned on.

[0024] The control signal levels corresponding to S1, S4, S6, and S8 are high, high, high, and low, respectively; the control signal levels corresponding to S2, S3, S5, and S7 are high, low, high, and low, respectively.

[0025] Furthermore, the inductor current flows through the switching devices S1 and S4 and the capacitor C. F1 The voltage across inductor L is charged to V. IN -3V O Capacitor C F2 The lower plate is grounded and simultaneously supplies power to the load until the voltage across the capacitor discharges to V. O .

[0026] Furthermore, the inductor L is connected in parallel with the capacitor CF1, and with the capacitor C... F2 Series connection; one end of inductor L is grounded, and the voltage at the other end is 2V. O The voltage across the terminals is -2V O The inductor current gradually decreases; the capacitor C F1 The lower plate is grounded and in a discharging state until the capacitor terminals discharge to 2V. O .

[0027] The beneficial effects of this invention are as follows:

[0028] This invention proposes a hybrid switching power supply converter and its control method. Addressing the problems of excessive average inductor current, high losses, and low efficiency in existing buck converters, this invention utilizes a dual-path supply to the load via both capacitors and inductors. By designing eight switching devices, this invention reduces switching and inductor losses, improves operating efficiency, and achieves a significant step-down conversion, meeting the needs of low-power applications. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the circuit system of a hybrid switching power supply converter according to the present invention.

[0030] Figure 2 This is a schematic diagram of the current flow of the first type of control method for a hybrid switching power converter according to the present invention.

[0031] Figure 3 This is a schematic diagram of the current flow direction of the second type of control method for a hybrid switching power converter according to the present invention.

[0032] Figure 4 This is a timing diagram of the control signals of eight switching devices in the power control method of a hybrid switching power converter according to the present invention.

[0033] Figure 5 This is a comparison diagram of the inductor current of a hybrid switching power converter according to the present invention with that of CPL-Buck and conventional Buck.

[0034] Figure 6 This is a comparison chart of the voltage conversion ratio of the power control method of the hybrid switching power converter of the present invention with that of CPL-Buck and conventional Buck.

[0035] Figure 7 This is a schematic diagram of a conventional buck converter circuit system.

[0036] Figure 8 This is a schematic diagram of an existing capacitor-inductor series-buck converter circuit system. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0038] Example 1

[0039] like Figure 1 As shown, a hybrid switching power supply converter includes eight switching devices S1-S8 and two energy storage capacitors C. F1 and C F2 1 inductor L;

[0040] S1 source electrical connection input voltage V IN The drain of S1 is electrically connected to one end of inductor L and the drain of S2, respectively; the source of S2 is electrically connected to ground; the source of S3 is electrically connected to the other end of inductor L and the energy storage capacitor C, respectively. F1 The upper plate of S3 is electrically connected, and the drain of S3 is connected to the energy storage capacitor C. F2 The upper plate of S4, the drain of S4, and the drain of S6 are electrically connected; the source of S4 is connected to the energy storage capacitor C. F1 The lower plate of S5 is electrically connected to the drain of S5; the source of S5 is connected to ground; the source of S6 is electrically connected to the source of S7; the drain of S7 is connected to the energy storage capacitor C. F2 The lower plate of S6 is electrically connected to the drain of S8; the source of S8 is connected to ground; the voltage between the sources of S6 and S7 is called the output voltage V. O .

[0041] This invention discloses a hybrid buck converter with two energy transmission paths in each operating phase. Compared with existing solutions, it significantly reduces the average inductor current, as well as switching losses and inductor losses, thereby extending the service life of the equipment and improving working efficiency.

[0042] Compared with existing solutions, the hybrid buck converter of the present invention can achieve a greater buck conversion at the same duty cycle, which simplifies the circuit design and further improves the performance.

[0043] The buck converter of the present invention has very low voltage stress on each switch, and can be integrated using ordinary CMOS devices without the need for special high voltage devices, thus saving chip area and cost.

[0044] Example 2

[0045] like Figure 1 As shown, a hybrid switching power supply converter includes eight switching devices S1-S8 and two energy storage capacitors C. F1 and C F2 1 inductor L;

[0046] S1 source electrical connection input voltage V IN The drain of S1 is electrically connected to one end of inductor L and the drain of S2, respectively; the source of S2 is electrically connected to ground; the source of S3 is electrically connected to the other end of inductor L and the energy storage capacitor C, respectively. F1 The upper plate of S3 is electrically connected, and the drain of S3 is connected to the energy storage capacitor C. F2 The upper plate of S4, the drain of S4, and the drain of S6 are electrically connected; the source of S4 is connected to the energy storage capacitor C. F1The lower plate of S5 is electrically connected to the drain of S5; the source of S5 is connected to ground; the source of S6 is electrically connected to the source of S7; the drain of S7 is connected to the energy storage capacitor C. F2 The lower plate of S6 is electrically connected to the drain of S8; the source of S8 is connected to ground; the voltage between the sources of S6 and S7 is called the output voltage V. O .

[0047] In one specific embodiment, a load capacitor C is also included. L C L The upper plates are electrically connected to the source electrodes of S6 and S7, respectively; C L The lower electrode is connected to ground level.

[0048] In one specific embodiment, S1, S3, S4, S6, and S7 are all PMOS transistors.

[0049] In one specific embodiment, S2, S5, and S8 are all NMOS transistors.

[0050] In one specific embodiment, the source of S6 and the source of S7 are also electrically connected to the current detection device.

[0051] In one specific embodiment, the source of S6 and the source of S7 are also electrically connected to the voltage detection device.

[0052] Example 3

[0053] A control method for a hybrid switching power supply converter:

[0054] When the duty cycle of the switching signal of the hybrid switching power supply converter is the set threshold D, the control switching devices S2, S3, S5, and S7 are turned off; S1, S4, S6, and S8 are turned on.

[0055] The control signal levels corresponding to S2, S3, S5, and S7 are low, high, low, and high, respectively; the control signal levels corresponding to S1, S4, S6, and S8 are low, low, low, and high, respectively.

[0056] like Figure 2 As shown, in one specific embodiment, the inductor current flows through switching devices S1 and S4 and capacitor C. F1 The voltage across inductor L is charged to V. IN -3V O Capacitor C F2 The lower plate is grounded and simultaneously supplies power to the load until the voltage across the capacitor discharges to V. O .

[0057] Example 4

[0058] A control method for a hybrid switching power supply converter:

[0059] When the duty cycle of the switching signal of the hybrid switching power supply converter is the set threshold 1-D, the control switching devices S1, S4, S6, and S8 are turned off; S2, S3, S5, and S7 are turned on.

[0060] The control signal levels corresponding to S1, S4, S6, and S8 are high, high, high, and low, respectively; the control signal levels corresponding to S2, S3, S5, and S7 are high, low, high, and low, respectively.

[0061] like Figure 3 As shown, in one specific embodiment, inductor L is connected in parallel with capacitor CF1, and capacitor C... F2 Series connection; one end of inductor L is grounded, and the voltage at the other end is 2V. O The voltage across the terminals is -2V O The inductor current gradually decreases; the capacitor C F1 The lower plate is grounded and in a discharging state until the capacitor terminals discharge to 2V. O .

[0062] Example 5

[0063] In this embodiment, the volt-second balance law of inductor L can be used to obtain:

[0064] (V IN -3V O D = 2V O (1-D)

[0065] Solving for the voltage conversion ratio M yields the following result:

[0066]

[0067] From capacitor C F1 C F2 and C L The charge balance law yields the expression for the average inductor current:

[0068]

[0069] From this, we can obtain the following... Figure 5 The diagram shows the timing of the control signals for the eight switching devices of a hybrid switching power supply converter.

[0070] In this embodiment, the voltage stress of the 8 switches is shown in Table 1:

[0071] Switching devices

[001] S1 [S2] [S3] [S4] [S5] <![CDATA[S6]]> <![CDATA[S7]]> <![CDATA[S8]]> Voltage stress <![CDATA[V IN ]]> <![CDATA[V IN ]]> <![CDATA[V O ]]> <![CDATA[2V O ]]> <![CDATA[V O ]]> <![CDATA[V O ]]> <![CDATA[V O ]]> <![CDATA[V O ]]>

[0072] Since the input voltage is between 4.2 and 2.8V and the output voltage is below 1V, the voltage stress of all switching MOSFETs can be below 5V, eliminating the need for special high-voltage devices and allowing for manufacturing using ordinary CMOS processes.

[0073] The present invention discloses a hybrid switching power converter structure in which two energy transmission paths are continuously provided to the load in each operating state, which significantly reduces the average inductor current, as well as the switching loss and inductor loss, extending the service life of the equipment and improving the working efficiency. Due to the use of two flying capacitors, the voltage conversion ratio can be reduced to a lower level under the same duty cycle signal, so as to achieve a significant step-down conversion.

[0074] In this embodiment, as Figure 5 As shown, since the input voltage is between 4.2-2.8V and the output voltage is below 1V, the voltage stress of all switching MOSFETs in this invention can be below 5V, eliminating the need for special high-voltage devices and allowing for manufacturing using ordinary CMOS processes.

[0075] In this embodiment, as Figure 6 As shown, under the same duty cycle D, the buck converter proposed in this invention can achieve a lower voltage conversion ratio, which means that it can more easily achieve a significant buck conversion compared to existing technologies.

[0076] This invention proposes a hybrid switching power converter that addresses the problems of excessive average inductor current, high losses, and low efficiency in existing buck converters. It utilizes a dual-path supply of capacitors and inductors to power the load and reduces the average inductor current by designing eight switching devices, thereby reducing switching and inductor losses and improving operating efficiency. At the same time, it achieves a significant buck conversion to meet the needs of low-power application scenarios.

[0077] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A hybrid switching power supply converter, characterized in that: Includes 8 switching devices S1-S8 and 2 energy storage capacitors C F1 and C F2 1 inductor L; S1 source electrical connection input voltage V IN The drain of S1 is electrically connected to one end of inductor L and the drain of S2, respectively; the source of S2 is electrically connected to ground; the source of S3 is electrically connected to the other end of inductor L and the energy storage capacitor C, respectively. F1 The upper plate of S3 is electrically connected, and the drain of S3 is connected to the energy storage capacitor C. F2 The upper plate of S4, the drain of S4, and the drain of S6 are electrically connected; the source of S4 is connected to the energy storage capacitor C. F1 The lower plate of S5 is electrically connected to the drain of S5; the source of S5 is connected to ground; the source of S6 is electrically connected to the source of S7; the drain of S7 is connected to the energy storage capacitor C. F2 The lower plate of S6 is electrically connected to the drain of S8; the source of S8 is connected to ground; the voltage between the sources of S6 and S7 is called the output voltage V. O .

2. The hybrid switching power supply converter according to claim 1, characterized in that: It also includes a load capacitor C L C L The upper plates are electrically connected to the source electrodes of S6 and S7, respectively; C L The lower electrode is connected to ground level.

3. The hybrid switching power supply converter according to claim 1, characterized in that: S1, S3, S4, S6, and S7 are all PMOS transistors.

4. The hybrid switching power supply converter according to claim 1, characterized in that: S2, S5, and S8 are all NMOS transistors.

5. The hybrid switching power supply converter according to claim 1, characterized in that: The sources of S6 and S7 are also electrically connected to the current detection device.

6. The hybrid switching power supply converter according to claim 1, characterized in that: The sources of S6 and S7 are also electrically connected to the voltage detection device.

7. A control method for a hybrid switching power supply converter as described in any one of claims 1 to 6, characterized in that: When the duty cycle of the switching signal of the hybrid switching power supply converter is the set threshold D, the control switching devices S2, S3, S5, and S7 are turned off; S1, S4, S6, and S8 are turned on. The control signal levels corresponding to S2, S3, S5, and S7 are low, high, low, and high, respectively; the control signal levels corresponding to S1, S4, S6, and S8 are low, low, low, and high, respectively.

8. The power control method for the hybrid switching power supply converter according to claim 7, characterized in that: Inductor current flows through switching devices S1 and S4 and capacitor C F1 The voltage across inductor L is charged to V. IN -3V O Capacitor C F2 The lower plate is grounded and simultaneously supplies power to the load until the voltage across the capacitor discharges to V. O .

9. A control method for a hybrid switching power supply converter as described in any one of claims 1 to 6, characterized in that: When the duty cycle of the switching signal of the hybrid switching power converter is the set threshold 1-D, the control switching devices S1, S4, S6, and S8 are turned off; S2, S3, S5, and S7 are turned on. The control signal levels corresponding to S1, S4, S6, and S8 are high, high, high, and low, respectively; the control signal levels corresponding to S2, S3, S5, and S7 are high, low, high, and low, respectively.

10. The power control method for the hybrid switching power supply converter according to claim 9, characterized in that: Inductor L is connected in parallel with capacitor CF1, and capacitor C is connected in parallel with capacitor C. F2 Series connection; one end of inductor L is grounded, and the voltage at the other end is 2V. O The voltage across the terminals is -2V O The inductor current gradually decreases; the capacitor C F1 The lower plate is grounded and in a discharging state until the capacitor terminals discharge to 2V. O .

Images