Reverse leakage prevention switched capacitor voltage converter, chip and electronic device
By using logic control circuitry in the switched capacitor voltage converter to cut off the leakage path between the body diode of the switching transistor and the control terminal, the reverse leakage problem of the switched capacitor voltage converter is solved, resulting in a smaller chip area and higher charging efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHUHAI NANXIN SEMICON TECH CO LTD
- Filing Date
- 2024-11-14
- Publication Date
- 2026-06-02
AI Technical Summary
Existing switched capacitor voltage converters waste electrical energy when the voltage VIN leaks to a low voltage, and the introduction of additional power transistors increases chip area and cost, while reducing charging efficiency.
When the switched capacitor voltage converter is not in operation, the logic control circuit controls the body diode and control terminal of the switching transistor to conduct to ground, cuts off the leakage path, prevents reverse leakage, and avoids the introduction of additional power transistors.
It effectively prevents reverse leakage in switched capacitor voltage converters, reduces chip area, lowers costs, and improves charging efficiency.
Smart Images
Figure CN119448762B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of power management chip technology, and in particular to a switched capacitor voltage converter, chip and electronic device that prevents reverse leakage. Background Technology
[0002] A switched-capacitor voltage converter (SVC) is a DC-DC converter that utilizes capacitors for energy storage. Compared to inductors, capacitors have a higher energy density; therefore, the conversion efficiency of a SVC using capacitors for energy transfer is significantly higher than that of a voltage converter using inductors. Due to its high energy conversion efficiency, the SVC is widely used in various charging scenarios to achieve voltage-to-current conversion between input and output ratios. The SVC achieves high power density and multiple outputs with a relatively small overall circuit design.
[0003] See Figure 1 , Figure 1 A single-input multiple-output switched-capacitor voltage converter is provided for related technologies, such as... Figure 1 As shown, this switched capacitor voltage converter can control the connection relationship of capacitors C1A, C1B, C2A, and C2B by controlling the on or off state of power transistors M1 to M16, thereby achieving different ratio conversions between input and output. Figure 1 In this configuration, input terminal IN_1 is connected to voltage VIN, the first output terminal OUT_1 outputs the first voltage VOUT, and the second output terminal VO1_1 outputs the second voltage VMID, thus achieving a single-input multiple-output function. For example, see [link to example]. Figure 1 By controlling power transistors M1, M4, M7, M9, M11, M12, M14, and M15 to be turned on, and power transistors M2, M3, M5, M6, M8, M10, M13, and M16 to be turned off, and through the series-parallel relationship between capacitors C1A, C1B, C2A, and C2B, a 4:1 voltage reduction function can be achieved, i.e., VIN = 4 * VOUT.
[0004] In practical applications of switched capacitor voltage converters, when the voltage VIN leaks to a low voltage, the first voltage VOUT will leak to VIN through the switched capacitor voltage converter, resulting in a waste of electrical energy. Summary of the Invention
[0005] This application provides a switched capacitor voltage converter, chip, and electronic device with reverse leakage protection to reduce chip area, lower cost, and improve charging efficiency. The specific technical solution is as follows:
[0006] In a first aspect, this application provides a switched capacitor voltage converter that prevents reverse leakage current. The switched capacitor voltage converter includes: a logic control circuit, a first switching circuit, a second switching circuit, and a switched capacitor voltage conversion circuit. The switched capacitor voltage conversion circuit includes an input voltage terminal, an output voltage terminal, a first leakage path, and a second leakage path. The first leakage path includes a first leakage branch and a second leakage branch. The second leakage path includes a third leakage branch and a fourth leakage branch. Each of the first leakage branch, the second leakage branch, the third leakage branch, and the fourth leakage branch includes two switching transistors.
[0007] When the switched capacitor voltage converter is in a non-operating state, and the input voltage connected to the input voltage terminal is lower than the output voltage output to the output voltage terminal, and the absolute value of the difference between the input voltage and the output voltage is greater than a preset threshold:
[0008] The logic control circuit is used to control the first switching circuit so that the anodes of the body diodes of the first target switching transistor and the second target switching transistor are both connected to ground; and to control the second switching circuit so that the control terminals of the first target switching transistor and the second target switching transistor are both connected to ground; wherein, the first target switching transistor is any one of the switching transistors in the first leakage current branch, and the second target switching transistor is any one of the switching transistors in the third leakage current branch, or, the first target switching transistor is any one of the switching transistors in the second leakage current branch, and the second target switching transistor is any one of the switching transistors in the fourth leakage current branch.
[0009] In one possible design, for any of the target switching transistors:
[0010] The common terminal of the first switching circuit is electrically connected to the anode of the body diode of the target switching transistor, the first terminal of the first switching circuit is grounded, and the second terminal of the first switching circuit is electrically connected to the first terminal of the target switching transistor.
[0011] The common terminal of the second switching circuit is electrically connected to the control terminal of the target switching transistor, the first terminal of the second switching circuit is grounded, and the second terminal of the second switching circuit is electrically connected to the driving voltage terminal.
[0012] In one possible design, when the switched capacitor voltage converter is in operation, the logic control circuit controls the first switching circuit such that the anodes of the body diodes of both the first target switch and the second target switch are connected to the first terminal of the target switch; and controls the second switching circuit such that the control terminals of both the first target switch and the second target switch are connected to the driving voltage terminal, wherein the driving voltage terminal is electrically connected to the logic control circuit.
[0013] In one possible design, the switched capacitor voltage conversion circuit includes: a first switch transistor, a second switch transistor, a third switch transistor, a fourth switch transistor, a fifth switch transistor, a sixth switch transistor, a seventh switch transistor, an eighth switch transistor, a ninth switch transistor, a tenth switch transistor, an eleventh switch transistor, a twelfth switch transistor, a thirteenth switch transistor, a fourteenth switch transistor, a fifteenth switch transistor, a sixteenth switch transistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, and a sixth capacitor;
[0014] The first terminal of the first switching transistor is electrically connected to the first terminal of the first capacitor and the second terminal of the third switching transistor, and the second terminal of the first switching transistor is electrically connected to the second terminal of the sixteenth switching transistor and the input voltage terminal.
[0015] The first terminal of the second switch is grounded, and the second terminal of the second switch is electrically connected to the second terminal of the first capacitor and the first terminal of the fourth switch, respectively.
[0016] The first terminal of the third switch is electrically connected to the second terminal of the fifth switch, the first terminal of the fifth capacitor, the second terminal of the twelfth switch, and the first terminal of the fourteenth switch, respectively.
[0017] The second terminal of the fourth switch is electrically connected to the first terminal of the twelfth switch, the second terminal of the sixth switch, and the first terminal of the second capacitor, respectively.
[0018] The first terminal of the fifth switch is electrically connected to the second terminal of the thirteenth switch, the second terminal of the eleventh switch, and the first terminal of the fourth capacitor, respectively.
[0019] The first terminal of the sixth switch is electrically connected to the second terminal of the seventh switch, the first terminal of the eleventh switch, the second terminal of the tenth switch, and the first terminal of the sixth capacitor.
[0020] The first terminal of the seventh switch is electrically connected to the second terminal of the second capacitor and the second terminal of the eighth switch, respectively.
[0021] The first terminal of the eighth switch is grounded;
[0022] The first terminal of the ninth switch is grounded, and the second terminal of the ninth switch is electrically connected to the first terminal of the tenth switch and the second terminal of the fourth capacitor, respectively.
[0023] The first terminal of the thirteenth switch is electrically connected to the second terminal of the third capacitor and the second terminal of the fifteenth switch, respectively.
[0024] The second terminal of the fourteenth switch is electrically connected to the first terminal of the third capacitor and the first terminal of the sixteenth switch, respectively.
[0025] The first terminal of the fifteenth switch is grounded, the second terminal of the fifth capacitor is grounded, and the second terminal of the sixth capacitor is grounded.
[0026] The control terminals of the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, the eighth switch, the ninth switch, the tenth switch, the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, the fifteenth switch, and the sixteenth switch are all electrically connected to the logic control circuit.
[0027] In one possible design, the first leakage path includes: the first switch, the third switch, the fifth switch, and the eleventh switch, and the second leakage path includes: the sixth switch, the twelfth switch, the fourteenth switch, and the sixteenth switch.
[0028] In one possible design, the first leakage current branch includes: the first switch and the third switch; the second leakage current branch includes: the fifth switch and the eleventh switch; the third leakage current branch includes: the fourteenth switch and the sixteenth switch; and the fourth leakage current branch includes: the sixth switch and the twelfth switch.
[0029] In one possible design, the preset threshold is the minimum of the sum of four times the forward conduction threshold of the body diode and the conduction thresholds of the four switching transistors on the leakage path.
[0030] In one possible design, the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, the eighth switch, the ninth switch, the tenth switch, the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, the fifteenth switch, and the sixteenth switch are all N-type switches.
[0031] In a second aspect, this application provides a chip comprising: a switched-capacitor voltage converter as described in the first aspect.
[0032] Thirdly, this application provides an electronic device, including: a chip as described in the second aspect.
[0033] The beneficial effects of the embodiments of this application are as follows:
[0034] In this embodiment, when the switched-capacitor voltage converter is in a non-operating state, and the input voltage at the input voltage terminal is lower than the output voltage at the output voltage terminal, and the absolute value of the difference between the input voltage and the output voltage is greater than a preset threshold, the logic control circuit controls the first switching circuit so that the anodes of the body diodes of both the first and second target switching transistors are connected to ground, cutting off the leakage path through the body diodes of the switching transistors; and controls the second switching circuit so that the control terminals of both the first and second target switching transistors are connected to ground, cutting off the reverse leakage path through the channel of the switching transistors. By cutting off the leakage paths of the body diodes and channels of the switching transistors, the leakage path from the output voltage terminal OUT to the input voltage terminal IN is completely cut off, preventing reverse leakage of the switched-capacitor voltage converter. Since this application does not require the introduction of additional power transistors, the chip area is reduced, the cost is lowered, and the charging efficiency is improved.
[0035] The beneficial effects provided in the second aspect and its various possible designs can be found in the first aspect and its various possible implementations, and will not be repeated here. Attached Figure Description
[0036] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.
[0037] Figure 1 A schematic diagram of a single-input multiple-output switched-capacitor voltage converter provided for related technologies;
[0038] Figure 2 A leakage protection circuit provided for related technologies;
[0039] Figure 3 A schematic diagram of a switched capacitor voltage converter structure for preventing reverse leakage is provided in an embodiment of this application;
[0040] Figure 4 A circuit diagram of a switched capacitor voltage converter with reverse leakage protection provided in an embodiment of this application. Detailed Implementation
[0041] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c alone can mean: a alone, b alone, c alone, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0042] The terms “center,” “longitudinal,” “lateral,” “up,” “down,” “left,” “right,” “front,” and “rear,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0043] The terms "connected" and "connected" should be interpreted broadly. For example, in circuit structures, "connected" or "connected" can refer not only to physical connections but also to electrical or signal connections. This could be a direct connection (physical connection) or an indirect connection via at least one intermediate component, as long as the circuit is connected. It could also refer to the internal connection between two components. Similarly, a signal connection can refer to a connection via a circuit or a medium, such as radio waves. Those skilled in the art will understand the specific meaning of these terms in this application based on the specific circumstances.
[0044] In related technologies, to prevent leakage current from the output terminal to the input terminal of a switched capacitor voltage converter, thus avoiding energy waste, a leakage current protection circuit is provided. (See [link to relevant documentation]). Figure 2 ,like Figure 2 As shown, this scheme inserts a power transistor QB between the input terminal IN_1 and the switched capacitor voltage converter. The body diode of the power transistor QB points from VIN to PMID. When the power transistor QB is turned off, the reverse leakage path from the output terminal OUT_1 to the input terminal IN_1 in the switched capacitor voltage converter can be directly cut off.
[0045] See Figure 2The technical solution of inserting an additional power transistor QB can prevent leakage from the output terminal OUT_1 to the input terminal IN_1 in the switched capacitor voltage converter. However, the additional power transistor QB requires additional area overhead, which will increase the chip area and increase the cost. In addition, during the normal operation of the switched capacitor voltage converter, the charging current flowing from the input terminal IN_1 will flow through the power transistor QB, generating additional power loss, resulting in a decrease in charging efficiency and an increase in chip heat generation.
[0046] To address the issues of large chip area, high cost, and low charging efficiency caused by introducing additional power transistors in related technologies, this application provides a switched capacitor voltage converter with reverse leakage protection, which can prevent reverse leakage of the switched capacitor voltage converter without introducing power transistors.
[0047] To reduce chip area, lower costs, and improve charging efficiency, this application provides a switched capacitor voltage converter, chip, and electronic device that prevents reverse leakage.
[0048] Among them, the switched capacitor voltage converter that prevents reverse leakage can be a chip or a circuit module.
[0049] The chip may include a switched-capacitor voltage converter that prevents reverse leakage.
[0050] In this application, electronic devices may include, but are not limited to: adapters, chargers, tablets, smart home devices, vehicles, and wearable devices.
[0051] See Figure 3 , Figure 3 This is a schematic diagram of a switched capacitor voltage converter 1000 with reverse leakage protection provided in an embodiment of this application, as shown below. Figure 3 As shown, the reverse leakage-proof switched capacitor voltage converter 1000 includes: a logic control circuit 100, a first switching circuit 200, a second switching circuit 300, and a switched capacitor voltage conversion circuit 400. The switched capacitor voltage conversion circuit 400 includes an input voltage terminal IN, an output voltage terminal OUT, a first leakage path, and a second leakage path. The first leakage path includes a first leakage branch and a second leakage branch, and the second leakage path includes a third leakage branch and a fourth leakage branch. Each of the first leakage branch, the second leakage branch, the third leakage branch, and the fourth leakage branch includes two switching transistors.
[0052] When the switched capacitor voltage converter is not in operation, and the input voltage Vin connected to the input voltage terminal IN is lower than the output voltage Vout output to the output voltage terminal OUT, and the absolute value of the difference between the input voltage Vin and the output voltage Vout is greater than a preset threshold:
[0053] The logic control circuit 100 controls the first switching circuit 200 such that the anodes of the body diodes of both the first target switching transistor and the second target switching transistor are connected to ground; and controls the second switching circuit 300 such that the control terminals of both the first target switching transistor and the second target switching transistor are connected to ground; wherein the first target switching transistor is any one of the switching transistors in the first leakage current branch, and the second target switching transistor is any one of the switching transistors in the third leakage current branch, or the first target switching transistor is any one of the switching transistors in the second leakage current branch, and the second target switching transistor is any one of the switching transistors in the fourth leakage current branch.
[0054] When the input voltage Vin leaks to a low voltage, causing the input voltage Vin to be lower than the output voltage Vout, and the absolute value of the difference between the input voltage Vin and the output voltage Vout is greater than a preset threshold, there will be a problem of reverse leakage from the output voltage Vout to the input voltage Vin.
[0055] The leakage path from the output voltage terminal OUT to the input voltage terminal IN of the switched capacitor voltage converter includes a first leakage path and a second leakage path. The first leakage path includes a first leakage branch and a second leakage branch, while the second leakage path includes a third leakage branch and a fourth leakage branch. Each of the first, second, third, and fourth leakage branches includes two switching transistors. That is, both the first and second leakage paths involve four switching transistors. The output voltage Vout at the output voltage terminal OUT needs to pass through these four switching transistors to leak to the input voltage terminal IN. The preset threshold is related to the forward conduction threshold of the body diode of the switching transistor and the conduction threshold of the switching transistor itself. The relationship between the preset threshold and these two factors will be explained in detail later.
[0056] The main reasons for reverse leakage in switched-capacitor voltage converters are twofold: First, leakage occurs through the body diode of the switching transistor, causing the output voltage Vout to leak into the input voltage Vin. Second, in conventional designs, the gate voltage of the switching transistor is biased to its source. Therefore, when the input voltage Vin is too low, the voltage difference between the gate and drain of the switching transistor exceeds the switching threshold voltage, causing the output voltage Vout to leak through the channel of the switching transistor into the input voltage Vin. In other words, reverse leakage in switched-capacitor voltage converters primarily occurs through the body diode of the switching transistor, and also through the channel of the switching transistor when the voltage difference between the gate and drain exceeds the switching threshold voltage.
[0057] Based on the analysis of the causes of reverse leakage in switched capacitor voltage converters, in order to prevent reverse leakage when the switched capacitor voltage converter is in a non-operating state, this application uses a logic control circuit to control the first switching circuit so that the anodes of the body diodes of the first and second target switching transistors are both connected to ground, thus cutting off the path of leakage through the body diodes of the switching transistors; and controls the second switching circuit so that the control terminals of the first and second target switching transistors are both connected to ground. At this time, the voltage difference between the gate and drain of the switching transistor is less than the switching threshold voltage, thus cutting off the path of reverse leakage through the channel of the switching transistor.
[0058] To effectively prevent reverse leakage in the switched capacitor voltage converter, the leakage path from the output voltage terminal OUT to the input voltage terminal IN needs to be completely cut off. This means cutting off the first and second leakage paths. Since the first leakage path includes a first and a second leakage branch, and the second leakage path includes a third and a fourth leakage branch, and each of these branches includes two switching transistors, at least two switching transistors are required to completely cut off the first and second leakage paths and prevent reverse leakage.
[0059] Therefore, the first target switch can be any switch in the first leakage current branch, the second target switch can be any switch in the third leakage current branch, or the first target switch can be any switch in the second leakage current branch, and the second target switch can be any switch in the fourth leakage current branch.
[0060] In this embodiment, when the switched-capacitor voltage converter is in a non-operating state, and the input voltage at the input voltage terminal is lower than the output voltage at the output voltage terminal, and the absolute value of the difference between the input voltage and the output voltage is greater than a preset threshold, the logic control circuit controls the first switching circuit so that the anodes of the body diodes of both the first and second target switching transistors are connected to ground; and controls the second switching circuit so that the control terminals of both the first and second target switching transistors are connected to ground. By cutting off the leakage path of the body diodes and channels of the switching transistors, the leakage path from the output voltage terminal OUT to the input voltage terminal IN is completely cut off, preventing reverse leakage of the switched-capacitor voltage converter. Since this application does not require the introduction of additional power transistors, the chip area is reduced, the cost is lowered, and the charging efficiency is improved.
[0061] In one possible embodiment, see Figure 4 , Figure 4 A switched capacitor voltage converter with reverse leakage protection provided in this application embodiment, such as... Figure 4As shown, for any target switch (e.g., Q6 or Q11):
[0062] The common terminal of the first switching circuit 200 is electrically connected to the anode of the body diode of the target switching transistor (Q6 or Q11), the first terminal of the first switching circuit 200 is grounded, and the second terminal of the first switching circuit 200 is electrically connected to the first terminal of the target switching transistor (Q6 or Q11).
[0063] The common terminal of the second switching circuit 300 is electrically connected to the control terminal of the target switching transistor (Q6 or Q11), the first terminal of the second switching circuit 300 is grounded, and the second terminal of the second switching circuit 300 is electrically connected to the drive voltage terminal DRV.
[0064] The drive voltage terminal DRV is used to provide voltage to the control terminal of the target switch. In practical project applications, the voltage range of the drive voltage terminal DRV is usually set to Vout to Vout+5V. The voltage of the drive voltage terminal DRV is switched between Vout and Vout+5V by a logic control circuit to control the on or off state of the target switch. Those skilled in the art will understand that when the voltage of the drive voltage terminal DRV is greater than Vout+Vth, the target switch will be turned on, where Vth is the switching threshold voltage between the gate and source of the target switch, which is typically less than 5V. For example, when the voltage of the drive voltage terminal DRV is Vout, the target switch is off because the source voltage of the target switch is Vout; when the voltage of the drive voltage terminal DRV is Vout+Vth, the target switch is turned on because the source voltage of the target switch is Vout.
[0065] In one possible embodiment, see Figure 4 When the switched capacitor voltage converter is in operation, the logic control circuit 100 controls the first switching circuit 200 so that the anodes of the body diodes of the first target switch and the second target switch are both connected to the first terminal of the target switch; and controls the second switching circuit 300 so that the control terminals of the first target switch and the second target switch are both connected to the driving voltage terminal DRV, wherein the driving voltage terminal DRV is electrically connected to the logic control circuit 100.
[0066] The reverse leakage protection of the switched capacitor voltage converter in this application is performed when the input voltage at the input voltage terminal is lower than the output voltage at the output voltage terminal, and the absolute value of the difference between the input voltage and the output voltage is greater than a preset threshold. Therefore, when the switched capacitor voltage converter is in operation, the anodes of the body diodes of the first target switch and the second target switch do not need to be grounded, and the control terminals of the first target switch and the second target switch also do not need to be grounded.
[0067] In one possible embodiment, see Figure 4 The switched capacitor voltage conversion circuit 400 includes: a first switch Q1, a second switch Q2, a third switch Q3, a fourth switch Q4, a fifth switch Q5, a sixth switch Q6, a seventh switch Q7, an eighth switch Q8, a ninth switch Q9, a tenth switch Q10, an eleventh switch Q11, a twelfth switch Q12, a thirteenth switch Q13, a fourteenth switch Q14, a fifteenth switch Q15, a sixteenth switch Q16, a first capacitor CF1A, a second capacitor CF2A, a third capacitor CF1B, a fourth capacitor CF2B, a fifth capacitor COUT1, and a sixth capacitor COUT2.
[0068] The first terminal of the first switch Q1 is electrically connected to the first terminal of the first capacitor CF1A and the second terminal of the third switch Q3, respectively. The second terminal of the first switch Q1 is electrically connected to the second terminal of the sixteenth switch Q16 and the input voltage terminal IN, respectively.
[0069] The first terminal of the second switch Q2 is grounded, and the second terminal of the second switch Q2 is electrically connected to the second terminal of the first capacitor CF1A and the first terminal of the fourth switch Q4, respectively.
[0070] The first terminal of the third switch Q3 is electrically connected to the second terminal of the fifth switch Q5, the first terminal of the fifth capacitor COUT1, the second terminal of the twelfth switch Q12, and the first terminal of the fourteenth switch Q14.
[0071] The second terminal of the fourth switch Q4 is electrically connected to the first terminal of the twelfth switch Q12, the second terminal of the sixth switch Q6, and the first terminal of the second capacitor CF2A.
[0072] The first terminal of the fifth switch Q5 is electrically connected to the second terminal of the thirteenth switch Q13, the second terminal of the eleventh switch Q11, and the first terminal of the fourth capacitor CF2B.
[0073] The first terminal of the sixth switch Q6 is electrically connected to the second terminal of the seventh switch Q7, the first terminal of the eleventh switch Q11, the second terminal of the tenth switch Q10, and the first terminal of the sixth capacitor COUT2.
[0074] The first terminal of the seventh switch Q7 is electrically connected to the second terminal of the second capacitor CF2A and the second terminal of the eighth switch Q8.
[0075] The first terminal of the eighth switch Q8 is grounded.
[0076] The first terminal of the ninth switch Q9 is grounded, and the second terminal of the ninth switch Q9 is electrically connected to the first terminal of the tenth switch Q10 and the second terminal of the fourth capacitor CF2B.
[0077] The first terminal of the thirteenth switch Q13 is electrically connected to the second terminal of the third capacitor CF1B and the second terminal of the fifteenth switch Q15.
[0078] The second terminal of the fourteenth switch Q14 is electrically connected to the first terminal of the third capacitor CF1B and the first terminal of the sixteenth switch Q16, respectively.
[0079] The first terminal of the fifteenth switch Q15 is grounded, the second terminal of the fifth capacitor COUT1 is grounded, and the second terminal of the sixth capacitor COUT2 is grounded.
[0080] The control terminals of the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, the sixth switch Q6, the seventh switch Q7, the eighth switch Q8, the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11, the twelfth switch Q12, the thirteenth switch Q13, the fourteenth switch Q14, the fifteenth switch Q15, and the sixteenth switch Q16 are all electrically connected to the logic control circuit 100.
[0081] In one possible embodiment, see Figure 4 The first leakage path includes: the first switch Q1, the third switch Q3, the fifth switch Q5 and the eleventh switch Q11, and the second leakage path includes: the sixth switch Q6, the twelfth switch Q12, the fourteenth switch Q14 and the sixteenth switch Q16.
[0082] See Figure 4 The switching transistors involved in the leakage path from the output voltage terminal OUT to the input voltage terminal IN of the switched capacitor voltage converter are: the first switch Q1, the third switch Q3, the fifth switch Q5, the eleventh switch Q11, the sixth switch Q6, the twelfth switch Q12, the fourteenth switch Q14, and the sixteenth switch Q16. These switches can be divided into a first leakage path and a second leakage path. The leakage from the output voltage terminal OUT to the input voltage terminal IN of the switched capacitor voltage converter can occur through either the first leakage path or the second leakage path.
[0083] In one possible embodiment, see Figure 4 The first leakage current branch includes: the first switch Q1 and the third switch Q3; the second leakage current branch includes: the fifth switch Q5 and the eleventh switch Q11; the third leakage current branch includes: the fourteenth switch Q14 and the sixteenth switch Q16; and the fourth leakage current branch includes: the sixth switch Q6 and the twelfth switch Q12.
[0084] Figure 4It includes two output terminals: the output voltage terminal OUT and the intermediate voltage terminal VO1, which are used for the output voltages Vout and Vmid, respectively. Taking the intermediate voltage terminal VO1 as the intermediate node, the first leakage path can be divided into a first leakage branch and a second leakage branch, and the second leakage path can be divided into a third leakage branch and a fourth leakage branch.
[0085] See Figure 4 The topology of a switched capacitor voltage converter with reverse leakage protection requires that all leakage paths from the output voltage terminal OUT to the input voltage terminal IN be cut off. This means that the first and second leakage paths need to be cut off. Therefore, at least two switching transistors need to be selected, and the original electrical connection between the body diode and the control terminal of the switching transistors needs to be disconnected and pulled down to ground. Only in this way can the first and second leakage paths be completely cut off to prevent reverse leakage.
[0086] Therefore, when selecting the first target switch and the second target switch, the first target switch can be any switch in the first leakage current branch, and the second target switch can be any switch in the third leakage current branch; or, the first target switch can be any switch in the second leakage current branch, and the second target switch can be any switch in the fourth leakage current branch. The following lists eight possible combinations of the first and second target switching transistors: Combination 1: Q1 and Q16; Combination 2: Q1 and Q14; Combination 3: Q3 and Q16; Combination 4: Q3 and Q14; Combination 5: Q5 and Q12; Combination 6: Q5 and Q6; Combination 7: Q11 and Q12; Combination 8: Q11 and Q6. To clearly explain the circuit's operating principle... Figure 4 In this paper, only combination 8 (the first target switch and the second target switch are Q11 and Q6) is used as an example to draw the relevant circuit electrical connection relationship. The electrical connection relationship of all combinations is not drawn. It can be understood that the electrical connection relationship of other combinations is the same as that of combination 8.
[0087] In one possible embodiment, the preset threshold is the minimum of the sum of four times the forward conduction threshold of the body diode and the conduction thresholds of the four switching transistors on the leakage path.
[0088] See Figure 4The leakage path from the output voltage terminal OUT to the input voltage terminal IN of the switched capacitor voltage converter includes two leakage paths, each containing four switching transistors. Reverse leakage from the output voltage terminal OUT to the input voltage terminal IN can occur through the body diodes of the four switching transistors or through the channels of the four switching transistors. Specifically, when the absolute value of the difference between the input voltage and the output voltage is greater than four times the forward conduction threshold of the body diode, leakage can occur through the body diodes of the four switching transistors; when the absolute value of the difference between the input voltage and the output voltage is greater than the sum of the conduction thresholds of the four switching transistors, leakage can occur through the channels of the four switching transistors. Reverse leakage occurs when the minimum sum of the forward conduction threshold of the body diode (4 times the threshold value) and the conduction threshold of the four switching transistors in the leakage path is reached. That is, when the preset threshold reaches the minimum sum of the forward conduction threshold of the body diode (4 times the threshold value) and the conduction threshold of the four switching transistors in the leakage path, reverse leakage will occur from the output voltage terminal OUT to the input voltage terminal IN. The logic control circuit needs to control the target switching transistor to cut off the leakage path of the body diode and channel of the switching transistor, so that the leakage path from the output voltage terminal OUT to the input voltage terminal IN is completely cut off, thus preventing reverse leakage of the switched capacitor voltage converter.
[0089] In one possible embodiment, the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, the sixth switch Q6, the seventh switch Q7, the eighth switch Q8, the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11, the twelfth switch Q12, the thirteenth switch Q13, the fourteenth switch Q14, the fifteenth switch Q15, and the sixteenth switch Q16 are all N-type switches.
[0090] In the embodiments of this application, the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, the sixth switch Q6, the seventh switch Q7, the eighth switch Q8, the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11, the twelfth switch Q12, the thirteenth switch Q13, the fourteenth switch Q14, the fifteenth switch Q15, and the sixteenth switch Q16 can all be N-type field-effect transistors. The control terminals of the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, the sixth switch Q6, the seventh switch Q7, the eighth switch Q8, the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11, the twelfth switch Q12, the thirteenth switch Q13, the fourteenth switch Q14, the fifteenth switch Q15, and the sixteenth switch Q16 refer to the gate of the field-effect transistor. The first terminal of each of the following transistors (Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, Q10, Q11, Q12, Q13, Q14, Q15, and Q16) refers to the source of the field-effect transistor (FET). Correspondingly, the second terminal of each of the following transistors (Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, Q10, Q11, Q12, Q13, Q14, Q15, and Q16) refers to the drain of the FET.
[0091] See Figure 4Taking combination 8 as an example, when the switched capacitor voltage converter is in a non-operating state, the input voltage Vin connected to the input voltage terminal IN is lower than the output voltage Vout output to the output voltage terminal OUT, and the difference between the input voltage Vin and the output voltage Vout reaches the minimum of the sum of four times the forward conduction threshold of the body diode and the conduction threshold of the four switching transistors on the leakage path (i.e., when the absolute value of the difference between the input voltage and the output voltage is greater than the preset threshold): the logic control circuit controls the anode of the body diode of switching transistors Q11 and Q6 to disconnect from the output voltage terminal OUT and connect to ground, cutting off the leakage path through the body diode of the switching transistors; and controls the gate of switching transistors Q11 and Q6 to disconnect from the drive voltage terminal and connect to ground, cutting off the reverse leakage path through the channel of the switching transistors. By cutting off the leakage path of the body diode and the channel of the switching transistors, the leakage path from the output voltage terminal OUT to the input voltage terminal IN is completely cut off, preventing reverse leakage of the switched capacitor voltage converter. Since this application does not require the introduction of additional power transistors, it reduces chip area, lowers cost, and improves charging efficiency.
[0092] This application also provides a chip, including: the above-described switched capacitor voltage converter.
[0093] This application also provides an electronic device, including the chip described above.
[0094] Finally, it should be noted that the above embodiments are merely specific implementations of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A switched-capacitor voltage converter with reverse leakage protection, characterized in that, The switched capacitor voltage converter includes: a logic control circuit, a first switching circuit, a second switching circuit, and a switched capacitor voltage conversion circuit. The switched capacitor voltage conversion circuit includes an input voltage terminal, an output voltage terminal, a first leakage path, and a second leakage path. The first leakage path includes a first leakage branch and a second leakage branch. The second leakage path includes a third leakage branch and a fourth leakage branch. Each of the first leakage branch, the second leakage branch, the third leakage branch, and the fourth leakage branch includes two switching transistors. The logic control circuit is electrically connected to the first switching circuit, the second switching circuit, and the switched capacitor voltage conversion circuit, respectively; the input voltage terminal is electrically connected to the first terminal of the first leakage branch and the first terminal of the third leakage branch, respectively; the second terminal of the first leakage branch is electrically connected to the first terminal of the second leakage branch; the second terminal of the third leakage branch is electrically connected to the first terminal of the fourth leakage branch; and the second terminals of the second leakage branch and the second terminal of the fourth leakage branch are both electrically connected to the output voltage terminal. When the switched capacitor voltage converter is in a non-operating state, and the input voltage connected to the input voltage terminal is lower than the output voltage output to the output voltage terminal, and the absolute value of the difference between the input voltage and the output voltage is greater than a preset threshold: The logic control circuit is used to control the first switching circuit so that the anodes of the body diodes of the first target switching transistor and the second target switching transistor are both connected to ground; and to control the second switching circuit so that the control terminals of the first target switching transistor and the second target switching transistor are both connected to ground; wherein, the first target switching transistor is any one of the switching transistors in the first leakage current branch, and the second target switching transistor is any one of the switching transistors in the third leakage current branch, or, the first target switching transistor is any one of the switching transistors in the second leakage current branch, and the second target switching transistor is any one of the switching transistors in the fourth leakage current branch; For any of the target switching transistors described above: The common terminal of the first switching circuit is electrically connected to the anode of the body diode of the target switching transistor, the first terminal of the first switching circuit is grounded, and the second terminal of the first switching circuit is electrically connected to the first terminal of the target switching transistor. The common terminal of the second switching circuit is electrically connected to the control terminal of the target switching transistor, the first terminal of the second switching circuit is grounded, and the second terminal of the second switching circuit is electrically connected to the driving voltage terminal.
2. The switched capacitor voltage converter according to claim 1, characterized in that, When the switched capacitor voltage converter is in operation, the logic control circuit controls the first switching circuit so that the anodes of the body diodes of the first target switch and the second target switch are both connected to the first terminal of the target switch; and controls the second switching circuit so that the control terminals of the first target switch and the second target switch are both connected to the driving voltage terminal, wherein the driving voltage terminal is electrically connected to the logic control circuit.
3. The switched capacitor voltage converter according to claim 1, characterized in that, The switched capacitor voltage conversion circuit includes: a first switch transistor, a second switch transistor, a third switch transistor, a fourth switch transistor, a fifth switch transistor, a sixth switch transistor, a seventh switch transistor, an eighth switch transistor, a ninth switch transistor, a tenth switch transistor, an eleventh switch transistor, a twelfth switch transistor, a thirteenth switch transistor, a fourteenth switch transistor, a fifteenth switch transistor, a sixteenth switch transistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, and a sixth capacitor; The first terminal of the first switching transistor is electrically connected to the first terminal of the first capacitor and the second terminal of the third switching transistor, and the second terminal of the first switching transistor is electrically connected to the second terminal of the sixteenth switching transistor and the input voltage terminal. The first terminal of the second switch is grounded, and the second terminal of the second switch is electrically connected to the second terminal of the first capacitor and the first terminal of the fourth switch, respectively. The first terminal of the third switch is electrically connected to the second terminal of the fifth switch, the first terminal of the fifth capacitor, the second terminal of the twelfth switch, and the first terminal of the fourteenth switch, respectively. The second terminal of the fourth switch is electrically connected to the first terminal of the twelfth switch, the second terminal of the sixth switch, and the first terminal of the second capacitor, respectively. The first terminal of the fifth switch is electrically connected to the second terminal of the thirteenth switch, the second terminal of the eleventh switch, and the first terminal of the fourth capacitor, respectively. The first terminal of the sixth switch is electrically connected to the second terminal of the seventh switch, the first terminal of the eleventh switch, the second terminal of the tenth switch, and the first terminal of the sixth capacitor. The first terminal of the seventh switch is electrically connected to the second terminal of the second capacitor and the second terminal of the eighth switch, respectively. The first terminal of the eighth switch is grounded; The first terminal of the ninth switch is grounded, and the second terminal of the ninth switch is electrically connected to the first terminal of the tenth switch and the second terminal of the fourth capacitor, respectively. The first terminal of the thirteenth switch is electrically connected to the second terminal of the third capacitor and the second terminal of the fifteenth switch, respectively. The second terminal of the fourteenth switch is electrically connected to the first terminal of the third capacitor and the first terminal of the sixteenth switch, respectively. The first terminal of the fifteenth switch is grounded, the second terminal of the fifth capacitor is grounded, and the second terminal of the sixth capacitor is grounded. The control terminals of the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, the eighth switch, the ninth switch, the tenth switch, the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, the fifteenth switch, and the sixteenth switch are all electrically connected to the logic control circuit.
4. The switched capacitor voltage converter according to claim 3, characterized in that, The first leakage path includes: the first switch, the third switch, the fifth switch, and the eleventh switch; the second leakage path includes: the sixth switch, the twelfth switch, the fourteenth switch, and the sixteenth switch.
5. The switched capacitor voltage converter according to claim 4, characterized in that, The first leakage current branch includes: the first switch and the third switch; the second leakage current branch includes: the fifth switch and the eleventh switch; the third leakage current branch includes: the fourteenth switch and the sixteenth switch; and the fourth leakage current branch includes: the sixth switch and the twelfth switch.
6. The switched capacitor voltage converter according to claim 1, characterized in that, The preset threshold is the minimum value between the sum of the conduction thresholds of the four switching transistors on the leakage path and four times the forward conduction threshold of the body diode.
7. The switched capacitor voltage converter according to claim 3, characterized in that, The first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, the eighth switch, the ninth switch, the tenth switch, the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, the fifteenth switch, and the sixteenth switch are all N-type switches.
8. A chip, characterized in that, include: The switched capacitor voltage converter as described in any one of claims 1-7.
9. An electronic device, characterized in that, include: The chip as described in claim 8.