Switched capacitor converter soft start control circuit
By incorporating multiple control circuits in the switched capacitor boost converter to control the soft-start process, the problem of component damage caused by peak current is solved, and safe voltage boost conversion is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SG MICRO CORP
- Filing Date
- 2022-09-05
- Publication Date
- 2026-06-19
Smart Images
Figure CN116191851B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of integrated circuits, and more specifically, to a soft-start control circuit for a switched-capacitor converter. Background Technology
[0002] Compared to traditional switching power supplies, switched-capacitor converters eliminate the need for inductive components, resulting in higher conversion efficiency and power density. However, because switched-capacitor converters lack inductor current limiting, their output voltage is less susceptible to soft-start compared to traditional switching power supplies. For switched-capacitor boost converters, the output voltage is significantly higher than the input voltage, making soft-start even more challenging.
[0003] Existing voltage soft-start solutions generate high peak currents after the power transistor is turned on, which can easily damage the power transistor.
[0004] Therefore, soft-start of boost converters with switched capacitor architecture in the prior art is prone to causing component damage. Summary of the Invention
[0005] The main objective of this application is to provide a soft-start control circuit for a switched-capacitor converter, in order to solve the problem that soft-start of existing switched-capacitor architecture boost converters is prone to component damage, and to avoid the generation of high peak current in the power transistors during the soft-start process.
[0006] To achieve the above objectives, this application proposes a soft-start control circuit for a switched-capacitor converter, comprising: a switched-capacitor boost converter circuit, a first control circuit, a second control circuit, a third control circuit, and a fourth control circuit. The switched-capacitor boost converter circuit includes a first control signal input terminal, a second control signal input terminal, a third control signal input terminal, and a fourth control signal input terminal. The first control signal input terminal is connected to the output terminal of the first control circuit, the second control signal input terminal is connected to the output terminal of the second control circuit, the third control signal input terminal is connected to the output terminal of the third control circuit, and the fourth control signal input terminal is connected to the output terminal of the fourth control circuit. Wherein:
[0007] The first control circuit is configured to generate a first current when it is in a first control state and pass the first current to the switched capacitor boost converter circuit, and to generate a first control signal when it is in a second control state and pass the first control signal to the switched capacitor boost converter circuit.
[0008] The second control circuit is configured to generate a second current when in a third control state and pass the second current to the switched capacitor boost converter circuit, and to generate a second control signal when in a fourth control state and pass the second control signal to the switched capacitor boost converter circuit.
[0009] The third control circuit is configured to generate a third current when in the fifth control state and transmit the third current to the switched capacitor boost converter circuit, and to generate a third control signal when in the sixth control state and transmit the third control signal to the switched capacitor boost converter circuit.
[0010] The fourth control circuit is configured to generate a fourth current when in the seventh control state and transmit the fourth current to the switched capacitor boost converter circuit, and to generate a fourth control signal when in the eighth control state and transmit the fourth control signal to the switched capacitor boost converter circuit.
[0011] The switched capacitor boost converter circuit is configured to control the input voltage to be boosted based on the outputs of the first control circuit, the second control circuit, the third control circuit, and the fourth control circuit, until the output voltage of the switched capacitor boost converter circuit meets the voltage output rules, and then outputs the output voltage.
[0012] In some optional embodiments of this application, the first control circuit includes a first current generating circuit and a first control signal generating circuit.
[0013] When the first control circuit is in the first control state, the first current generating circuit operates, and the output terminal of the first current generating circuit is connected to the first control signal input terminal of the switched capacitor boost converter circuit.
[0014] When the first control circuit is in the second control state, the first control signal generating circuit operates, and the output terminal of the first control signal generating circuit is connected to the first control signal input terminal of the switched capacitor boost converter circuit.
[0015] In some optional embodiments of this application, the first current generating circuit includes a first current source and a first mirror transistor. The first mirror transistor and the first transistor in the switched capacitor boost converter circuit form a first current mirror structure. The first current source is configured to generate a first current and provide the first current to the first current mirror structure.
[0016] The first control signal generation circuit is configured to receive a first drive signal and generate a first control signal based on the first drive signal, and provide the first control signal to the switched capacitor boost converter circuit.
[0017] In some optional embodiments of this application, the switched capacitor boost converter circuit includes a voltage source, a voltage output circuit, a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor, a first flying capacitor, a second flying capacitor, and a third flying capacitor.
[0018] Wherein, the gate of the second transistor is coupled to the second control signal input terminal of the switched capacitor boost converter circuit, the first terminal of the second transistor is coupled to the positive terminal of the voltage source, and the second terminal of the second transistor is coupled to the first node;
[0019] The gate of the third transistor is coupled to the third control signal input terminal of the switched capacitor boost converter circuit, the first terminal of the third transistor is coupled to the first node, and the second terminal of the third transistor is coupled to the voltage terminal.
[0020] The gate of the first transistor is coupled to the first control signal input terminal of the switched capacitor boost converter circuit, the first electrode of the first transistor is coupled to the positive electrode of the voltage source, and the second electrode of the first transistor is coupled to the second node.
[0021] The gate of the fourth transistor is coupled to the fourth control signal input terminal of the switched capacitor boost converter circuit, the first terminal of the fourth transistor is coupled to the second node, and the second terminal of the fourth transistor is coupled to the voltage terminal.
[0022] The voltage source is configured to generate the input voltage, and the negative terminal of the voltage source is coupled to the voltage terminal;
[0023] The first terminal of the fifth transistor is coupled to the third node, and the second terminal of the fifth transistor is coupled to the positive terminal of the voltage source;
[0024] The first terminal of the sixth transistor is coupled to the fourth node, and the second terminal of the sixth transistor is coupled to the third node;
[0025] The first terminal of the seventh transistor is coupled to the fifth node, and the second terminal of the seventh transistor is coupled to the fourth node;
[0026] The first terminal of the eighth transistor is coupled to the voltage output circuit, and the second terminal of the eighth transistor is coupled to the fifth node;
[0027] One end of the first flying capacitor is coupled to the first node, and the other end of the first flying capacitor is coupled to the third node;
[0028] One end of the second flying capacitor is coupled to the second node, and the other end of the second flying capacitor is coupled to the fourth node;
[0029] One end of the third flying capacitor is coupled to the first node, and the other end of the third flying capacitor is coupled to the fifth node;
[0030] The input terminal of the voltage output circuit is coupled to the first terminal of the eighth transistor. The input terminal of the voltage output circuit is configured to generate the output voltage based on the current at the first terminal of the eighth transistor and output it through the output terminal of the voltage output circuit.
[0031] In some optional embodiments of this application, the switched capacitor boost converter circuit includes a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, and an eighth transistor.
[0032] When the third control circuit is in the fifth control state and the fourth control circuit is in the seventh control state, the first transistor and the second transistor are turned off, and the third transistor, the fourth transistor, the fifth transistor, the sixth transistor and the seventh transistor are turned on, and the switched capacitor boost converter circuit enters the pre-charging state.
[0033] When the first control circuit is in the first control state, the second control circuit is in the third control state, the third control circuit is in the sixth control state, and the fourth control circuit is in the eighth control state, the switched capacitor boost converter circuit is configured to control the operating states of the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor, the sixth transistor, the seventh transistor, and the eighth transistor according to the third control signal and the fourth control signal, and the switched capacitor converter circuit enters the soft start state.
[0034] In some optional embodiments of this application, when the switched capacitor conversion circuit enters the soft-start state,
[0035] When the third control signal is a high-phase signal, the first transistor, the third transistor, the fifth transistor, and the seventh transistor are turned on, and the second transistor, the fourth transistor, the sixth transistor, and the eighth transistor are turned off.
[0036] When the fourth control signal is a high-phase signal, the first transistor, the third transistor, the fifth transistor, and the seventh transistor are turned off, and the second transistor, the fourth transistor, the sixth transistor, and the eighth transistor are turned on.
[0037] After the switched capacitor conversion circuit enters the soft-start state, the switched capacitor conversion circuit is configured to alternately generate the third control signal as a high-phase signal and the fourth control signal as a high-phase signal, so as to realize the boost conversion of the input voltage until the output terminal of the voltage output circuit meets the voltage output rule and outputs the output voltage.
[0038] In some alternative embodiments of this application, the first terminal of the first current source is coupled to the fourth node of the switched capacitor boost converter circuit, the second terminal of the first current source is coupled to the first electrode of the first mirror transistor, the second electrode of the first mirror transistor is coupled to the second node of the switched capacitor boost converter circuit, the gate of the first mirror transistor is coupled to the first control signal input terminal of the switched capacitor boost converter circuit, and the gate of the first mirror transistor is coupled to the first electrode of the first mirror transistor.
[0039] In some optional embodiments of this application, the second control circuit includes a second current generating circuit and a second control signal generating circuit, wherein the second current generating circuit operates when the second control circuit is in a third control state; the second current generating circuit includes a second current source and a second mirror transistor, the second mirror transistor and the second transistor in the switched capacitor boost converter circuit form a second current mirror structure, and the second current source is configured to generate a second current and provide the second current to the second current mirror structure;
[0040] The third control circuit includes a third current generation circuit and a third control signal generation circuit. When the third control circuit is in the fifth control state, the third current generation circuit is operational. The third current generation circuit includes a third current source and a third mirror transistor. The third mirror transistor and the third transistor in the switched capacitor boost converter circuit form a third current mirror structure. The third current source is configured to generate a third current and provide the third current to the third current mirror structure.
[0041] The fourth control circuit includes a fourth current generation circuit and a fourth control signal generation circuit. When the fourth control circuit is in the seventh control state, the fourth current generation circuit is operational. The fourth current generation circuit includes a fourth current source and a fourth mirror transistor. The fourth mirror transistor and the fourth transistor in the switched capacitor boost converter circuit form a fourth current mirror structure. The fourth current source is configured to generate a fourth current and provide the fourth current to the fourth current mirror structure.
[0042] In some optional embodiments of this application, the second control signal generating circuit is configured to receive a second drive signal and generate a second control signal according to the second drive signal, and provide the second control signal to the switched capacitor boost converter circuit;
[0043] The third control signal generation circuit is configured to receive a first drive signal and generate a third control signal according to the first drive signal, and provide the third control signal to the switched capacitor boost converter circuit.
[0044] The fourth control signal generation circuit is configured to receive the second drive signal and generate a fourth control signal based on the second drive signal, and provide the fourth control signal to the switched capacitor boost converter circuit.
[0045] In some optional embodiments of this application, the first terminal of the second current source is coupled to the third node of the switched capacitor boost converter circuit, the second terminal of the second current source is coupled to the first electrode of the second mirror transistor, the second electrode of the second mirror transistor is coupled to the first node of the switched capacitor boost converter circuit, the gate of the second mirror transistor is coupled to the second control signal input terminal of the switched capacitor boost converter circuit, and the gate of the second mirror transistor is coupled to the first electrode of the second mirror transistor.
[0046] The output terminal of the third current source is coupled to the first terminal of the third mirror transistor, the second terminal of the third mirror transistor is coupled to the voltage terminal, the gate of the third mirror transistor is coupled to the third control signal input terminal of the switched capacitor boost converter circuit, and the gate of the third mirror transistor is coupled to the first terminal of the third mirror transistor.
[0047] The output terminal of the fourth current source is coupled to the first terminal of the fourth mirror transistor, the second terminal of the fourth mirror transistor is coupled to the voltage terminal, the gate of the fourth mirror transistor is coupled to the fourth control signal input terminal of the switched capacitor boost converter circuit, and the gate of the fourth mirror transistor is coupled to the first terminal of the fourth mirror transistor.
[0048] The technical solutions provided by the embodiments of this application may include the following beneficial effects:
[0049] In this application, a soft-start control circuit for a switched-capacitor boost converter is provided, comprising a switched-capacitor boost converter circuit, a first control circuit, a second control circuit, a third control circuit, and a fourth control circuit. The switched-capacitor boost converter circuit is connected to the first, second, third, and fourth control circuits, respectively. The switched-capacitor boost converter circuit is configured to boost the input voltage based on the outputs of the first, second, third, and fourth control circuits until the output voltage of the switched-capacitor boost converter circuit meets the voltage output rules, and then outputs the output voltage. By setting the first, second, third, and fourth control circuits, the soft-start process of the switched-capacitor boost converter circuit is controlled, and the spike current generated during the soft-start process is controlled, thus solving the problem of easy component damage during soft-start of the switched-capacitor architecture boost converter. Attached Figure Description
[0050] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings:
[0051] Figure 1 A schematic diagram of a soft-start control circuit for a switched capacitor boost converter provided as an example of an embodiment of this application;
[0052] Figure 2 This is a schematic circuit diagram of a soft-start control circuit for a switched capacitor converter provided in an embodiment of this application. Detailed Implementation
[0053] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are also within the scope of protection of this disclosure.
[0054] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this subject matter pertains. It will be further understood that terms such as those defined in commonly used dictionaries shall be interpreted as having the meaning consistent with their meaning in the context of the specification and in the relevant art, and shall not be interpreted in an idealized or overly formal form unless otherwise explicitly defined herein. As used herein, the statement of “connecting” or “coupling” two or more parts together shall mean that these parts are directly joined together or joined through one or more intermediate components.
[0055] In all embodiments of this disclosure, since the source and drain (emitter and collector) of the transistor are symmetrical, and the conduction current directions between the source and drain (emitter and collector) of N-type and P-type transistors are opposite, the controlled middle terminal of the transistor is referred to as the gate, and the remaining two terminals of the transistor are referred to as the first terminal and the second terminal, respectively. Furthermore, terms such as "first" and "second" are used only to distinguish one component (or part of a component) from another component (or another part of a component).
[0056] In one optional embodiment of this application, a soft-start control circuit for a switched capacitor boost converter is provided. Figure 1 A schematic diagram of a soft-start control circuit for a switched capacitor boost converter provided as an example of an embodiment of this application is shown below. Figure 1 As shown, the soft-start control circuit for the switched-capacitor converter includes: a first control circuit 100, a second control circuit 200, a third control circuit 300, a fourth control circuit 400, and a switched-capacitor boost converter circuit 500. The switched-capacitor boost converter circuit 500 includes a first control signal input terminal, a second control signal input terminal, a third control signal input terminal, and a fourth control signal input terminal. The first control signal input terminal is connected to the output terminal of the first control circuit 100, the second control signal input terminal is connected to the output terminal of the second control circuit 200, the third control signal input terminal is connected to the output terminal of the third control circuit 300, and the fourth control signal input terminal is connected to the output terminal of the fourth control circuit 400.
[0057] The first control circuit 100 is configured to generate a first current when it is in a first control state and pass the first current to the switched capacitor boost converter circuit 500; and to generate a first control signal when it is in a second control state and pass the first control signal to the switched capacitor boost converter circuit 500.
[0058] The second control circuit 200 is configured to generate a second current when it is in the third control state and pass the second current to the switched capacitor boost converter circuit 500; and to generate a second control signal when it is in the fourth control state and pass the second control signal to the switched capacitor boost converter circuit 500.
[0059] The third control circuit 300 is configured to generate a third current when it is in the fifth control state and pass the third current to the switched capacitor boost converter circuit 500; and to generate a third control signal when it is in the sixth control state and pass the third control signal to the switched capacitor boost converter circuit 500.
[0060] The fourth control circuit 400 is configured to generate a fourth current when it is in the seventh control state and pass the fourth current to the switched capacitor boost converter circuit 500; and to generate a fourth control signal when it is in the eighth control state and pass the fourth control signal to the switched capacitor boost converter circuit 500.
[0061] The switched capacitor boost converter circuit 500 is configured to control the output voltage of the switched capacitor boost converter circuit to meet the voltage output rules according to the outputs of the first control circuit 100, the second control circuit 200, the third control circuit 300 and the fourth control circuit 400, and output the output voltage. The first control circuit, the second control circuit, the third control circuit and the fourth control circuit perform boost conversion control on the switched capacitor boost converter circuit to realize soft start of the switched capacitor boost converter circuit.
[0062] In one optional embodiment of this application, the first control circuit includes a first current generating circuit and a first control signal generating circuit. When the first control circuit is in a first control state, the first current generating circuit operates, and the output terminal of the first current generating circuit is connected to the first control signal input terminal of the switched capacitor boost converter circuit. When the first control circuit is in a second control state, the first control signal generating circuit operates, and the output terminal of the first control signal generating circuit is connected to the first control signal input terminal of the switched capacitor boost converter circuit.
[0063] The second control circuit includes a second current generating circuit and a second control signal generating circuit. When the second control circuit is in the third control state, the second current generating circuit is working, and the output terminal of the second current generating circuit is connected to the second control signal input terminal of the switched capacitor boost converter circuit. When the second control circuit is in the fourth control state, the second control signal generating circuit is working, and the output terminal of the second control signal generating circuit is connected to the second control signal input terminal of the switched capacitor boost converter circuit.
[0064] The third control circuit includes a third current generating circuit and a third control signal generating circuit. When the third control circuit is in the fifth control state, the third current generating circuit is working, and the output terminal of the third current generating circuit is connected to the third control signal input terminal of the switched capacitor boost converter circuit. When the third control circuit is in the sixth control state, the third control signal generating circuit is working, and the output terminal of the third control signal generating circuit is connected to the third control signal input terminal of the switched capacitor boost converter circuit.
[0065] The fourth control circuit includes a fourth current generating circuit and a fourth control signal generating circuit. When the fourth control circuit is in the seventh control state, the fourth current generating circuit operates, and its output terminal is connected to the fourth control signal input terminal of the switched capacitor boost converter circuit. When the fourth control circuit is in the eighth control state, the fourth control signal generating circuit operates, and its output terminal is connected to the fourth control signal input terminal of the switched capacitor boost converter circuit.
[0066] In another optional embodiment of this application, a soft-start control circuit for a switched-capacitor converter is provided. Figure 2 This application provides a schematic circuit diagram of a soft-start control circuit for a switched-capacitor converter, as shown in the embodiments of this application. Figure 2 In the example, the voltage terminal is grounded, and the first control circuit 100 and the switched capacitor boost converter circuit 500 are connected through the first switch S1. When the first control circuit 100 is in the first state, the control terminal of the first switch S1 is connected to the first terminal a. When the first control circuit 100 is in the second state, the control terminal of the first switch S1 is connected to the second terminal b.
[0067] The second control circuit 200 and the switched capacitor boost converter circuit 500 are connected through the second switch S2. When the second control circuit 200 is in the third state, the control terminal of the second switch S2 is connected to the first terminal a. When the second control circuit 200 is in the fourth state, the control terminal of the second switch S2 is connected to the second terminal b.
[0068] The third control circuit 300 and the switched capacitor boost converter circuit 500 are connected through the third switch S3. When the third control circuit 300 is in the fifth state, the control terminal of the third switch S3 is connected to the first terminal a. When the third control circuit 300 is in the sixth state, the control terminal of the third switch S3 is connected to the second terminal b.
[0069] The fourth control circuit 400 and the switched capacitor boost converter circuit 500 are connected through the fourth switch S4. When the fourth control circuit 400 is in the seventh state, the control terminal of the fourth switch S4 is connected to the first terminal a. When the second control circuit 200 is in the eighth state, the control terminal of the fourth switch S4 is connected to the second terminal b.
[0070] The first current generation circuit includes a first current source Iref1 and a first mirror transistor Q1-1. The first mirror transistor and the first transistor Q1 in the switched capacitor boost converter circuit form a first current mirror structure. The first current source is configured to generate a first current and provide a first current to the first current mirror structure. The first control signal generation circuit is configured to receive a first drive signal drv1 and generate a first control signal according to the first drive signal, and provide a first control signal to the switched capacitor boost converter circuit.
[0071] The second current generation circuit includes a second current source Iref2 and a second mirror transistor Q2-1. The second mirror transistor and the second transistor in the switched capacitor boost converter circuit form a second current mirror structure. The second current source is configured to generate a second current and provide a second current to the second current mirror structure. The second control signal generation circuit is configured to receive a second drive signal drv2 and generate a second control signal according to the second drive signal, and provide a second control signal to the switched capacitor boost converter circuit.
[0072] The third current generation circuit includes a third current source Iref3 and a third mirror transistor Q3-1. The third mirror transistor and the third transistor in the switched capacitor boost converter circuit form a third current mirror structure. The third current source is configured to generate a third current and provide a third current to the third current mirror structure. The third control signal generation circuit is configured to receive a first drive signal drv1 and generate a third control signal according to the first drive signal, and provide a third control signal to the switched capacitor boost converter circuit.
[0073] The fourth current generation circuit includes a fourth current source Iref4 and a fourth mirror transistor Q4-1. The fourth mirror transistor and the fourth transistor in the switched capacitor boost converter circuit form a fourth current mirror structure. The fourth current source is configured to generate a fourth current and provide a fourth current to the fourth current mirror structure. The fourth control signal generation circuit is configured to receive the second drive signal drv2 and generate a fourth control signal according to the second drive signal, and provide a fourth control signal to the switched capacitor boost converter circuit.
[0074] In another optional embodiment of this application, the first control signal generating circuit is configured to process the received first drive signal drv1 to generate a first control signal. The first control circuit is configured to convert the signal level of the first drive signal drv1 to a high level of CB2+5V and a low level of CB2 as a switching signal, so that the first transistor Q1 can switch normally. The negative power supply terminal is coupled to the second node CB2, and the positive power supply terminal is coupled to the first positive power supply terminal. The voltage of the first positive power supply terminal can be set to be 5V higher than the voltage of the second node CB2.
[0075] The second control signal generation circuit is configured to process the received second drive signal drv2 to generate a second control signal. The second control circuit is configured to convert the signal level of the second drive signal drv2 to a high level of CT1 and a low level of CB1 as a switching signal, so that the second transistor Q2 can switch normally. The negative power supply terminal is coupled to the first node CB1, and the positive power supply terminal is coupled to the third node CT1.
[0076] The third control signal generation circuit is configured to process the received first drive signal drv1 to generate a third control signal. The third control circuit is configured to process the first drive signal drv1 to generate a dead time. The negative power supply terminal is coupled to the voltage terminal, and the positive power supply terminal can be coupled to a second positive power supply terminal that is higher than the above voltage terminal +5V.
[0077] The fourth control signal generation circuit is configured to amplify the received second drive signal drv2 to generate a fourth control signal. The third control circuit is configured to process the second drive signal drv2 to generate a dead time. The negative power supply terminal is coupled to the voltage terminal, and the positive power supply terminal can be coupled to a third positive power supply terminal that is higher than the above voltage terminal +5V.
[0078] The switched capacitor boost converter circuit includes a voltage source, a voltage output circuit, a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, a fifth transistor Q5, a sixth transistor Q6, a seventh transistor Q7, an eighth transistor Q8, a first flying capacitor CFLY1, a second flying capacitor CFLY2, and a third flying capacitor CFLY3.
[0079] In one optional embodiment of this application, the gate of the second transistor is coupled to the second control signal input terminal of the switched capacitor boost converter circuit, the first terminal of the second transistor is coupled to the positive terminal of the voltage source, and the second terminal of the second transistor is coupled to the first node CB1.
[0080] The gate of the third transistor is coupled to the third control signal input terminal of the switched capacitor boost converter circuit, the first terminal of the third transistor is coupled to the first node CB1, and the second terminal of the third transistor is coupled to the voltage terminal.
[0081] The gate of the first transistor is coupled to the first control signal input terminal of the switched capacitor boost converter circuit, the first terminal of the first transistor is coupled to the positive terminal of the voltage source, and the second terminal of the first transistor is coupled to the second node CB2.
[0082] The gate of the fourth transistor is coupled to the fourth control signal input terminal of the switched capacitor boost converter circuit, the first terminal of the fourth transistor is coupled to the second node CB2, and the second terminal of the fourth transistor is coupled to the voltage terminal.
[0083] The voltage source is configured to generate an input voltage Vin, and the negative terminal of the voltage source is coupled to the voltage terminal.
[0084] The first terminal of the fifth transistor is coupled to the third node CT1, and the second terminal of the fifth transistor is coupled to the positive terminal of the voltage source.
[0085] The first terminal of the sixth transistor is coupled to the fourth node CT2, and the second terminal of the sixth transistor is coupled to the third node CT1.
[0086] The first terminal of the seventh transistor is coupled to the fifth node CT3, and the second terminal of the seventh transistor is coupled to the fourth node CT2.
[0087] The first terminal of the eighth transistor is coupled to the voltage output circuit, and the second terminal of the eighth transistor is coupled to the fifth node CT3.
[0088] One end of the first flying capacitor is coupled to the first node, and the other end of the first flying capacitor is coupled to the third node.
[0089] One end of the second flying capacitor is coupled to the second node, and the other end of the second flying capacitor is coupled to the fourth node;
[0090] One end of the third flying capacitor is coupled to the first node, and the other end of the third flying capacitor is coupled to the fifth node.
[0091] The input terminal of the voltage output circuit is coupled to the first terminal of the eighth transistor. The input terminal of the voltage output circuit is configured to generate an output voltage Vout based on the current at the output terminal of the first terminal of the eighth transistor and output it through the output terminal of the voltage output circuit. The voltage output circuit includes an output capacitor COUT, the first terminal of which is coupled to the voltage terminal, and the second terminal of which is coupled to the first terminal of the eighth transistor.
[0092] The first terminal of the first current source is coupled to the fourth node of the switched capacitor boost converter circuit, the second terminal of the first current source is coupled to the first electrode of the first mirror transistor, the second electrode of the first mirror transistor is coupled to the second node of the switched capacitor boost converter circuit, and the gate of the first mirror transistor is coupled to the first control signal input terminal of the switched capacitor boost converter circuit.
[0093] The first terminal of the second current source is coupled to the third node of the switched capacitor boost converter circuit, the second terminal of the second current source is coupled to the first terminal of the second mirror transistor, the second terminal of the second mirror transistor is coupled to the first node of the switched capacitor boost converter circuit, and the gate of the second mirror transistor is coupled to the second control signal input terminal of the switched capacitor boost converter circuit.
[0094] The output terminal of the third current source is coupled to the first terminal of the third mirror transistor, the second terminal of the third mirror transistor is coupled to the voltage terminal, and the gate of the third mirror transistor is coupled to the third control signal input terminal of the switched capacitor boost converter circuit.
[0095] The output terminal of the fourth current source is coupled to the first terminal of the fourth mirror transistor, the second terminal of the fourth mirror transistor is coupled to the voltage terminal, and the gate of the fourth mirror transistor is coupled to the fourth control signal input terminal of the switched capacitor boost converter circuit.
[0096] In another optional embodiment of this application, the first drive signal drv1 and the second drive signal drv2 are drive signals with a duty cycle of 50%. In the soft-start control circuit of the switched capacitor converter, the first mirror transistor Q1-1 and the first transistor Q1 form a first current mirror structure. When Q1 is turned on, the current flowing through Q1 is... The second mirror transistor Q2-1 and the second transistor Q2 form a second current mirror structure. When Q2 is turned on, the current flowing through Q2 is... The third current mirror structure is formed by the third transistor Q3-1 and the third transistor Q3. When Q3 is turned on, the current flowing through Q3 is... The fourth current mirror transistor Q4-1 and the fourth transistor Q4 form a fourth current mirror structure. When Q4 is turned on, the current flowing through Q4 is... Where W and L are the width and length of the transistor, respectively.
[0097] When the third control circuit is in the fifth control state and the fourth control circuit is in the seventh control state, the first and second transistors are turned off, and the third, fourth, fifth, sixth, and seventh transistors are turned on, and the switched capacitor boost converter circuit enters the pre-charging state.
[0098] In the pre-charge state, the first flying capacitor CFLY1, the second flying capacitor CFLY2, and the third flying capacitor CFLY3 are connected in parallel. The voltage source provides the input voltage Vin. The voltage source is turned off through the first and second transistors, and the third, fourth, fifth, sixth, and seventh transistors are turned on to pre-charge the first flying capacitor CFLY1, the second flying capacitor CFLY2, and the third flying capacitor CFLY3. The magnitude of the pre-charge current of the first flying capacitor CFLY1, the second flying capacitor CFLY2, and the third flying capacitor CFLY3 is controlled by the third and fourth current mirror structures. During this stage, the capacitor voltage of the first flying capacitor CFLY1, the second flying capacitor CFLY2, and the third flying capacitor CFLY3 can be charged to Vin.
[0099] When the first control circuit is in the first control state, the second control circuit is in the third control state, the third control circuit is in the sixth control state, and the fourth control circuit is in the eighth control state, the switched capacitor boost converter circuit is configured to control the operating states of the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor, the sixth transistor, the seventh transistor, and the eighth transistor according to the third control signal and the fourth control signal, and the switched capacitor converter circuit enters the soft start state.
[0100] In the soft-start state, when the first control circuit is in the first control state, the second control circuit is in the third control state, the third control circuit is in the sixth control state, and the fourth control circuit is in the eighth control state; when the third control signal is a high-phase signal, the first transistor, the third transistor, the fifth transistor, and the seventh transistor are turned on, and the second transistor, the fourth transistor, the sixth transistor, and the eighth transistor are turned off; when the fourth control signal is a high-phase signal, the first transistor, the third transistor, the fifth transistor, and the seventh transistor are turned off, and the second transistor, the fourth transistor, the sixth transistor, and the eighth transistor are turned on; after the switched capacitor conversion circuit enters the soft-start state, the switched capacitor conversion circuit is configured to alternately generate the third control signal as a high-phase signal and the fourth control signal as a high-phase signal, so as to realize the boost conversion of the input voltage until the output terminal of the voltage output circuit meets the voltage output rule and outputs the output voltage.
[0101] The third control signal is obtained by processing the first drive signal drv1, and the fourth control signal is obtained by processing the second drive signal drv2. In the soft-start state, there are two phase phases: the first phase is when the second drive signal drv2 is a high-phase signal, and the second phase is when the first drive signal drv1 is a high-phase signal.
[0102] When the second drive signal drv2 is a high-phase signal, transistors Q2 / Q4 / Q6 / Q8 are turned on, and transistors Q1 / Q3 / Q5 / Q7 are turned off. The input voltage Vin generated by the voltage source bootstraps the third node CT1 to 2Vin through the second transistor Q2. The third node then performs soft-start charging on the second flying capacitor CFLY2 through the sixth transistor Q6, with a charging current of I. Q4 (I Q4 ss2 The voltage increase of the second capacitor CFLY2 within one cycle is ΔV. CT2 =I Q4 *t2 / C FLY2 Simultaneously, the input voltage Vin generated by the voltage source first bootstraps the fifth node CT3 to 2Vin through the second transistor Q2. At this time, the input voltage Vin generated by the voltage source soft-starts the output capacitor COUT through the fifth node CT3, the second transistor Q2, and the eighth transistor Q8, with a charging current I. OUT Size I ss2 -I Q4 , among which, I Q4 This represents the current flowing from the input voltage Vin through the first flying capacitor CFLY1 to charge the second flying capacitor. The increase in output voltage VOUT within one cycle is ΔV. OUT =I OUT *t2 / C OUT Where t2 is the duration of the second driving signal drv2 as a high-phase signal within one cycle, and C FLY2 For the capacitance of the second capacitor, C OUT For the output capacitor, I OUT This represents the current supplied to the output capacitor COUT.
[0103] When the first drive signal drv1 is a high-phase signal, transistors Q1 / Q3 / Q5 / Q7 are turned on, and transistors Q2 / Q4 / Q6 / Q8 are turned off. The input voltage Vin generated by the voltage source replenishes the first flying capacitor CFLY1 to Vin through the third transistor Q3 (the first flying capacitor CFLY1 was consumed in the previous phase, and the amount consumed in the previous phase is the amount replenished). At the same time, the input voltage Vin generated by the voltage source first bootstraps the fourth node CT2 to 2Vin through the first transistor Q1. At this time, the input voltage Vin charges the third flying capacitor CFLY3 through the fourth node CT2 via the first transistor Q1 and the seventh transistor Q7, with a charging current of I. ss1 The voltage increase at the fifth node CT3 within one cycle is ΔV. CFLY3 =I ss1 *t1 / C FLY3 Where t1 is the duration of the first driving signal drv1 within one cycle when it is a high-phase signal, and C FLY3 This is the capacitance of the third flying capacitor.
[0104] The first phase and the second phase alternate continuously, and the output voltage V OUT The current rises slowly, and excessively high current spikes are avoided in the soft-start state by controlling the current of the first transistor Q1 and the second transistor Q2. After several soft-start cycles, C... FLY2 The voltage can be charged to 2V. IN C FLY3 The voltage is charged to 3V IN V OUT The voltage can be charged up to 4Vin. When V OUTWhen the voltage approaches 4*Vin, the control terminal of the first switch S1 is connected to the second terminal b, and the control terminal of the second switch S2 is connected to the second terminal b, completing the soft start of the output voltage and entering the normal working state.
[0105] In summary, this application provides a soft-start control circuit for a switched-capacitor boost converter, comprising a switched-capacitor boost converter circuit, a first control circuit, a second control circuit, a third control circuit, and a fourth control circuit. The switched-capacitor boost converter circuit is connected to the first, second, third, and fourth control circuits, respectively. The switched-capacitor boost converter circuit is configured to boost the input voltage based on the outputs of the first, second, third, and fourth control circuits until its output voltage meets the voltage output rules, at which point it outputs the output voltage. By configuring the first, second, third, and fourth control circuits to control the soft-start of the switched-capacitor boost converter circuit, the peak current generated during the soft-start process is controlled, thus solving the problem of component damage during soft-start of switched-capacitor architecture boost converters.
[0106] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.
[0107] Obviously, those skilled in the art should understand that the various units or steps of this application described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a storage device for execution by a computing device, or fabricating them separately as individual integrated circuit modules, or fabricating multiple modules or steps into a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.
[0108] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A switched-capacitor converter soft-start control circuit, comprising: include: The system comprises a switched-capacitor boost converter circuit, a first control circuit, a second control circuit, a third control circuit, and a fourth control circuit. The switched-capacitor boost converter circuit includes a first control signal input terminal, a second control signal input terminal, a third control signal input terminal, and a fourth control signal input terminal. The first control signal input terminal is connected to the output terminal of the first control circuit, the second control signal input terminal is connected to the output terminal of the second control circuit, the third control signal input terminal is connected to the output terminal of the third control circuit, and the fourth control signal input terminal is connected to the output terminal of the fourth control circuit. Wherein: The first control circuit is configured to generate a first current when it is in a first control state and pass the first current to the switched capacitor boost converter circuit, and to generate a first control signal when it is in a second control state and pass the first control signal to the switched capacitor boost converter circuit. The second control circuit is configured to generate a second current when in a third control state and pass the second current to the switched capacitor boost converter circuit, and to generate a second control signal when in a fourth control state and pass the second control signal to the switched capacitor boost converter circuit. The third control circuit is configured to generate a third current when in the fifth control state and transmit the third current to the switched capacitor boost converter circuit, and to generate a third control signal when in the sixth control state and transmit the third control signal to the switched capacitor boost converter circuit. The fourth control circuit is configured to generate a fourth current when in the seventh control state and transmit the fourth current to the switched capacitor boost converter circuit, and to generate a fourth control signal when in the eighth control state and transmit the fourth control signal to the switched capacitor boost converter circuit. The switched capacitor boost converter circuit is configured to control the input voltage to be boosted based on the outputs of the first control circuit, the second control circuit, the third control circuit, and the fourth control circuit, until the output voltage of the switched capacitor boost converter circuit meets the voltage output rules, and then outputs the output voltage.
2. The switched-capacitor converter soft-start control circuit of claim 1, wherein, The first control circuit includes a first current generating circuit and a first control signal generating circuit. When the first control circuit is in the first control state, the first current generating circuit operates, and the output terminal of the first current generating circuit is connected to the first control signal input terminal of the switched capacitor boost converter circuit. When the first control circuit is in the second control state, the first control signal generating circuit operates, and the output terminal of the first control signal generating circuit is connected to the first control signal input terminal of the switched capacitor boost converter circuit.
3. The soft-start control circuit for the switched-capacitor converter according to claim 2, characterized in that, The first current generating circuit includes a first current source and a first mirror transistor. The first mirror transistor and the first transistor in the switched capacitor boost converter circuit form a first current mirror structure. The first current source is configured to generate a first current and provide the first current to the first current mirror structure. The first control signal generation circuit is configured to receive a first drive signal and generate a first control signal based on the first drive signal, and provide the first control signal to the switched capacitor boost converter circuit.
4. The switched-capacitor converter soft-start control circuit of claim 1, wherein, The switched capacitor boost converter circuit includes a voltage source, a voltage output circuit, a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor, a first flying capacitor, a second flying capacitor, and a third flying capacitor. Wherein, the gate of the second transistor is coupled to the second control signal input terminal of the switched capacitor boost converter circuit, the first terminal of the second transistor is coupled to the positive terminal of the voltage source, and the second terminal of the second transistor is coupled to the first node; The gate of the third transistor is coupled to the third control signal input terminal of the switched capacitor boost converter circuit, the first terminal of the third transistor is coupled to the first node, and the second terminal of the third transistor is coupled to the voltage terminal. The gate of the first transistor is coupled to the first control signal input terminal of the switched capacitor boost converter circuit, the first electrode of the first transistor is coupled to the positive electrode of the voltage source, and the second electrode of the first transistor is coupled to the second node. The gate of the fourth transistor is coupled to the fourth control signal input terminal of the switched capacitor boost converter circuit, the first terminal of the fourth transistor is coupled to the second node, and the second terminal of the fourth transistor is coupled to the voltage terminal. The voltage source is configured to generate the input voltage, and the negative terminal of the voltage source is coupled to the voltage terminal; The first terminal of the fifth transistor is coupled to the third node, and the second terminal of the fifth transistor is coupled to the positive terminal of the voltage source; The first terminal of the sixth transistor is coupled to the fourth node, and the second terminal of the sixth transistor is coupled to the third node; The first terminal of the seventh transistor is coupled to the fifth node, and the second terminal of the seventh transistor is coupled to the fourth node; The first terminal of the eighth transistor is coupled to the voltage output circuit, and the second terminal of the eighth transistor is coupled to the fifth node; One end of the first flying capacitor is coupled to the first node, and the other end of the first flying capacitor is coupled to the third node; One end of the second flying capacitor is coupled to the second node, and the other end of the second flying capacitor is coupled to the fourth node; One end of the third flying capacitor is coupled to the first node, and the other end of the third flying capacitor is coupled to the fifth node; The input terminal of the voltage output circuit is coupled to the first terminal of the eighth transistor. The input terminal of the voltage output circuit is configured to generate the output voltage based on the current at the first terminal of the eighth transistor and output it through the output terminal of the voltage output circuit.
5. The soft-start control circuit for a switched-capacitor converter according to claim 1, characterized in that, The switched capacitor boost converter circuit includes a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, and an eighth transistor. When the third control circuit is in the fifth control state and the fourth control circuit is in the seventh control state, the first transistor and the second transistor are turned off, and the third transistor, the fourth transistor, the fifth transistor, the sixth transistor and the seventh transistor are turned on, and the switched capacitor boost converter circuit enters the pre-charging state. When the first control circuit is in the first control state, the second control circuit is in the third control state, the third control circuit is in the sixth control state, and the fourth control circuit is in the eighth control state, the switched capacitor boost converter circuit is configured to control the operating states of the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor, the sixth transistor, the seventh transistor, and the eighth transistor according to the third control signal and the fourth control signal, and the switched capacitor converter circuit enters the soft start state.
6. The soft-start control circuit for a switched-capacitor converter of claim 5, wherein, When the switched capacitor conversion circuit enters the soft-start state... When the third control signal is a high-phase signal, the first transistor, the third transistor, the fifth transistor, and the seventh transistor are turned on, and the second transistor, the fourth transistor, the sixth transistor, and the eighth transistor are turned off. When the fourth control signal is a high-phase signal, the first transistor, the third transistor, the fifth transistor, and the seventh transistor are turned off, and the second transistor, the fourth transistor, the sixth transistor, and the eighth transistor are turned on. After the switched capacitor conversion circuit enters the soft-start state, the switched capacitor conversion circuit is configured to alternately generate the third control signal as a high-phase signal and the fourth control signal as a high-phase signal, so as to realize the boost conversion of the input voltage until the output terminal of the voltage output circuit meets the voltage output rule and outputs the output voltage.
7. The soft-start control circuit for a switched-capacitor converter according to claim 1, characterized in that, The first terminal of the first current source is coupled to the fourth node of the switched capacitor boost converter circuit, the second terminal of the first current source is coupled to the first electrode of the first mirror transistor, the second electrode of the first mirror transistor is coupled to the second node of the switched capacitor boost converter circuit, the gate of the first mirror transistor is coupled to the first control signal input terminal of the switched capacitor boost converter circuit, and the gate of the first mirror transistor is coupled to the first electrode of the first mirror transistor.
8. The soft-start control circuit for a switched-capacitor converter according to claim 1, characterized in that, The second control circuit includes a second current generating circuit and a second control signal generating circuit. When the second control circuit is in a third control state, the second current generating circuit is operational. The second current generating circuit includes a second current source and a second mirror transistor. The second mirror transistor and the second transistor in the switched capacitor boost converter circuit form a second current mirror structure. The second current source is configured to generate a second current and provide the second current to the second current mirror structure. The third control circuit includes a third current generation circuit and a third control signal generation circuit. When the third control circuit is in the fifth control state, the third current generation circuit is operational. The third current generation circuit includes a third current source and a third mirror transistor. The third mirror transistor and the third transistor in the switched capacitor boost converter circuit form a third current mirror structure. The third current source is configured to generate a third current and provide the third current to the third current mirror structure. The fourth control circuit includes a fourth current generation circuit and a fourth control signal generation circuit. When the fourth control circuit is in the seventh control state, the fourth current generation circuit is operational. The fourth current generation circuit includes a fourth current source and a fourth mirror transistor. The fourth mirror transistor and the fourth transistor in the switched capacitor boost converter circuit form a fourth current mirror structure. The fourth current source is configured to generate a fourth current and provide the fourth current to the fourth current mirror structure.
9. The soft-start control circuit for a switched-capacitor converter according to claim 8, characterized in that, The second control signal generation circuit is configured to receive the second drive signal and generate the second control signal according to the second drive signal, and provide the second control signal to the switched capacitor boost converter circuit; The third control signal generation circuit is configured to receive a first drive signal and generate a third control signal according to the first drive signal, and provide the third control signal to the switched capacitor boost converter circuit. The fourth control signal generation circuit is configured to receive the second drive signal and generate a fourth control signal based on the second drive signal, and provide the fourth control signal to the switched capacitor boost converter circuit.
10. The soft-start control circuit for a switched-capacitor converter according to claim 1, characterized in that, The first terminal of the second current source is coupled to the third node of the switched capacitor boost converter circuit, the second terminal of the second current source is coupled to the first terminal of the second mirror transistor, the second terminal of the second mirror transistor is coupled to the first node of the switched capacitor boost converter circuit, the gate of the second mirror transistor is coupled to the second control signal input terminal of the switched capacitor boost converter circuit, and the gate of the second mirror transistor is coupled to the first terminal of the second mirror transistor. The output terminal of the third current source is coupled to the first terminal of the third mirror transistor, the second terminal of the third mirror transistor is coupled to the voltage terminal, the gate of the third mirror transistor is coupled to the third control signal input terminal of the switched capacitor boost converter circuit, and the gate of the third mirror transistor is coupled to the first terminal of the third mirror transistor. The output terminal of the fourth current source is coupled to the first terminal of the fourth mirror transistor, the second terminal of the fourth mirror transistor is coupled to the voltage terminal, the gate of the fourth mirror transistor is coupled to the fourth control signal input terminal of the switched capacitor boost converter circuit, and the gate of the fourth mirror transistor is coupled to the first terminal of the fourth mirror transistor.