Ripple generation circuit and COT control circuit

Abstract

The invention discloses a ripple generation circuit and a COT control circuit. The ripple generation circuit comprises a ripple generation module and a direct current elimination module, the ripple generation module comprises a first capacitor, a first resistor, a first switch, a voltage-controlled current source and a reference voltage; when the first switch is in an on state, the first capacitor discharges through the first resistor, and when the first switch is in an off state, the reference voltage controls the voltage-controlled current source to generate a first current, and charges the first capacitor through the first current to generate a first voltage with ripples; and the direct current elimination module is used for performing direct current sampling on the first voltage to obtain a direct current component and eliminating the direct current component to obtain a ripple voltage.

Description

Technical Field

[0001] This application relates to the field of power control technology, and more specifically, to a ripple generation circuit and a COT control circuit. Background Technology

[0002] The most common control mode in DC-DC converters is the constant on-time (COT) control mode. The output stability of this type of DC-DC converter is closely related to the equivalent series resistance (ESR) of the output capacitor. A reasonable ripple signal is needed to ensure the stability of the control loop in order to meet the precise requirements of the equipment for the power supply voltage.

[0003] In the existing technology, there are two common solutions for generating ripple in COT control: one is to use an electrolytic capacitor with a large ESR, which naturally generates ripple by utilizing the characteristics of the capacitor itself, without the need for an additional injection circuit; the other is to actively generate ripple by filtering the voltage of the switching node.

[0004] However, all of the above solutions have obvious drawbacks: the solution using electrolytic capacitors does not require additional circuitry, but the high ESR of the capacitors themselves will lead to excessive output voltage ripple, making it difficult to meet the low ripple power supply requirements of precision electronic equipment; the switching node filtering solution can only be adapted to single-phase COT control scenarios and cannot meet the ripple generation requirements under multi-phase COT control. Summary of the Invention

[0005] The main purpose of this application is to provide a ripple generation circuit and a COT control circuit to solve the problems of large output ripple and narrow adaptability of traditional ripple generation schemes, and to ensure loop stability and broaden circuit adaptability.

[0006] To achieve the above objectives, a first aspect of this application proposes a ripple generation circuit, comprising: a ripple generation module and a DC cancellation module; the ripple generation module includes a first capacitor, a first resistor, a first switch, a voltage-controlled current source, and a reference voltage; when the first switch is in an on state, the first capacitor discharges through the first resistor; when the first switch is in an off state, the reference voltage controls the voltage-controlled current source to generate a first current, and charges the first capacitor through the first current to generate a first voltage with ripple; the DC cancellation module is used to sample the first voltage to obtain a DC component, and obtain a ripple voltage by eliminating the DC component.

[0007] According to the ripple generation circuit provided in this application, the input terminal of the ripple generation module includes a power supply voltage terminal and a reference voltage terminal; when the first switch is in the open state, the power supply voltage connected to the power supply voltage terminal is used to provide working power for the voltage-controlled current source, and the reference voltage connected to the reference voltage terminal is used to convert the voltage-controlled current source into the first current according to the transconductance of the voltage-controlled current source.

[0008] According to the ripple generation circuit provided in this application, the power supply terminal of the voltage-controlled current source is connected to the power supply voltage terminal, the control terminal of the voltage-controlled current source is connected to the reference voltage terminal, the output terminal of the voltage-controlled current source is connected to one end of the first capacitor and one end of the first resistor respectively, the other end of the first capacitor is grounded, the other end of the first resistor is connected to one end of the first switch, and the other end of the first switch is grounded.

[0009] According to the ripple generation circuit provided in this application, the input terminal of the ripple generation module further includes a setting voltage terminal; when the first switch is in the on state, the setting voltage connected to the setting voltage terminal provides a charging path for the first capacitor through the first resistor.

[0010] According to a ripple generation circuit provided in this application, one end of the first switch is connected to the set voltage terminal, the other end of the first switch is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the first capacitor and the output terminal of the voltage-controlled current source, and the other end of the first capacitor is grounded.

[0011] According to a ripple generation circuit provided in this application, the voltage-controlled current source includes an operational amplifier, a first transistor, a second transistor, and a sampling resistor; the inverting input terminal of the operational amplifier is connected to the reference voltage terminal, the non-inverting input terminal of the operational amplifier is connected to one end of the sampling resistor, and the other end of the sampling resistor is grounded; the output terminal of the operational amplifier is connected to the gate of the first transistor, the drain of the first transistor is connected to one end of the sampling resistor, and the source of the first transistor is connected to the power supply voltage terminal; the gate of the second transistor is connected to the gate of the first transistor, the source of the second transistor is connected to the power supply voltage terminal, and the drain of the second transistor outputs the first current.

[0012] According to the ripple generation circuit provided in this application, the DC elimination module includes a DC sampling unit and an arithmetic unit; the input terminal of the DC sampling unit is connected to the output terminal of the ripple generation module, and is used to sample the first voltage to obtain the DC component; the two input terminals of the arithmetic unit are respectively connected to the output terminal of the ripple generation module and the output terminal of the DC sampling unit, and are used to subtract the first voltage from the DC component to eliminate the DC component and obtain the ripple voltage.

[0013] According to the ripple generation circuit provided in this application, the DC sampling unit is a multi-stage RC low-pass filter circuit.

[0014] According to the ripple generation circuit provided in this application, the DC sampling unit includes a second resistor, a third resistor, a second capacitor, and a third capacitor; the second resistor and the second capacitor form a first-stage filter, and the third resistor and the third capacitor form a second-stage filter.

[0015] This application also provides a COT control circuit, comprising: a ripple generation circuit as described in any of the above claims, a phase allocation unit, a main phase COT control loop, and at least one slave phase COT control loop; the output terminal of the ripple generation circuit is connected to the ripple injection terminal of the main phase COT control loop, the output terminal of the main phase COT control loop is connected to the input terminal of the phase allocation unit, and the output terminal of the phase allocation unit is connected to the input terminal of the at least one slave phase COT control loop; the phase allocation unit is used to receive the synchronization signal of the main phase COT control loop and generate a drive signal that is phase-interleaved with the main phase to drive the at least one slave phase COT control loop, thereby realizing the current sharing and interleaved operation of multiphase COT control.

[0016] The technical solutions provided by the embodiments of this application can include the following beneficial effects: Since the ripple generation module actively generates a first voltage with ripple by switching the first switch on and off to discharge the first capacitor and charge it driven by the voltage-controlled current source, it does not rely on the high ESR characteristics of the electrolytic capacitor, thus avoiding the problem of excessive output voltage ripple caused by high ESR in traditional electrolytic capacitor solutions, and meeting the low-ripple power supply requirements of precision equipment. Since the DC elimination module samples the first voltage using DC and eliminates the DC component to obtain the ripple voltage, this ripple generation method is not bound to the switch node signal, and therefore is not limited by the number of phases in COT control. It is suitable for both single-phase COT control and multi-phase COT control, broadening the circuit's adaptability. Since the generation of ripple is actively controlled by the on / off timing of the voltage-controlled current source, the first capacitor, and the first switch, the ripple parameters can be flexibly adjusted, ensuring the stability of the COT control loop and solving the loop instability problem of traditional solutions. Since the circuit of this application consists of a ripple generation module and a DC elimination module, it has no complex external components, has a simple overall structure, occupies a small chip area, and is easy to integrate into a DC-DC converter chip, which can reduce hardware costs and design complexity. Attached Figure Description

[0017] 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: Figure 1 The circuit schematic of a fixed on-time DC-DC converter with ripple injection is shown. Figure 2 One of the schematic diagrams of the ripple generation circuit provided in this application; Figure 3 Timing diagrams of each signal in the fixed on-time control mode provided in this application; Figure 4 A second schematic diagram of the ripple generation circuit provided in this application; Figure 5 This is a schematic diagram of the structure of the DC sampling unit provided in this application; Figure 6 This is a schematic diagram of the structure of the voltage-controlled current source provided in this application; Figure 7 This is a schematic diagram of the COT control circuit provided in this application. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application.

[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0020] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0021] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0022] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linked," and "socketing" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] This application describes some exemplary embodiments for illustrative purposes. It should be understood that this application may be implemented in other ways not specifically shown in the accompanying drawings.

[0024] like Figure 1 The diagram shows the circuit schematic of a fixed-on-time DC-DC converter using ripple injection. This circuit achieves output voltage stability through the synergy of the main power topology and the control loop. The main power section consists of an input voltage VIN, an upper power transistor P1, a lower power transistor P2, an inductor L, and an output capacitor COUT, forming a buck topology. The upper power transistor P1 and the lower power transistor P2 are controlled by the control logic module based on a Pulse Width Modulation (PWM) signal: when the PWM signal is high, the upper power transistor P1 is on, the node voltage at the SW terminal equals the input voltage VIN, and the inductor L begins to store energy, with the current gradually increasing; when the PWM signal is low, the lower power transistor P2 is on, the SW terminal is grounded, the inductor L releases the previously stored energy, the current gradually decreases, and finally, the output voltage VOUT is supplied to the load. The control loop compares the reference voltage VREF with the output voltage VOUT through the error amplifier EA, and outputs the control threshold Vc. The control threshold Vc is the integral value of the output voltage VOUT and the reference voltage VREF. When the entire control loop is in steady state, the output voltage VOUT is equal to the reference voltage VREF. At the same time, the ripple voltage Vripple is superimposed on the output voltage VOUT to obtain the ramp voltage Vn. When the ramp voltage Vn is less than the control threshold Vc, the comparator CMP outputs a high level, which triggers the COT generation module to generate a PWM signal with a fixed on-time Ton. This PWM signal drives the power transistor to turn on and off through the control logic module, completing one conduction cycle. Then, the cycle of "ramp voltage Vn decreases - comparator CMP is triggered - fixed on-time Ton is generated" is repeated. The loop instability problem under low ESR capacitance is solved by ripple injection, and finally a stable output of VOUT is achieved.

[0025] like Figure 2 As shown in the figure, this application provides a ripple generation circuit for generating ripples such as... Figure 1The circuit illustrates the ripple voltage Vripple. This ripple generation circuit includes a ripple generation module 110 and a DC cancellation module 120. The ripple generation module 110 includes a first capacitor Cx, a first resistor Rx, a first switch S0, a voltage-controlled current source VCCS, and a reference voltage VREF. When the first switch S0 is on, the first capacitor Cx discharges through the first resistor Rx. When the first switch S0 is off, the reference voltage VREF controls the voltage-controlled current source VCCS to generate a first current Ix, which charges the first capacitor Cx to generate a ripple-containing first voltage Vx. The DC cancellation module 120 samples the first voltage Vx to obtain a DC component and cancels the DC component to obtain the ripple voltage Vripple.

[0026] Specifically, in the ripple generation module 110, the conduction and disconnection of the first switch S0 are synchronously controlled by a PWM signal: when the PWM is high, a pulse voltage of duration Tnx can be generated to turn on the first switch S0, and the first capacitor Cx can discharge through the first resistor Rx for a duration of Tnx; after discharging for Tnx, the first switch S0 is turned off, and the reference voltage VREF can control the voltage-controlled current source VCCS to generate a first current Ix to charge the first capacitor Cx, thereby generating a periodic first voltage Vx with ripple through the charge-discharge cycle. The DC elimination module 120 performs DC sampling on the first voltage Vx to accurately obtain its DC component; then, through calculation, the DC component is stripped, retaining only the AC ripple part to obtain the ripple voltage Vripple.

[0027] Combination Figures 1-2 As shown, Figure 3 The timing diagram illustrates the interrelationship of various signals under the fixed on-time control mode. The ramp voltage Vn is... Figure 1 The signal resulting from the superposition of the output voltage VOUT and the ripple voltage Vripple exhibits a periodically decreasing triangular wave shape. When the ramp voltage Vn drops to the control threshold voltage Vc, a new control cycle is triggered. The duration of the entire control cycle is TSW. The SW terminal signal corresponds to the PWM signal. Figure 1The signals driving the power transistors have a high-level duration of a fixed on-time Ton. During Ton, the upper power transistor P1 is turned on and the inductor stores energy. After the fixed on-time Ton ends, the upper power transistor P1 is turned off and the inductor releases energy. The on-time of the control switch S0 is Tnx, and the timing of the on-time Tnx is completely synchronized with the high-level phases of PWM and SW. When the control switch S0 is turned on during the on-time Tnx, the first capacitor Cx will discharge through the first resistor Rx, causing the ramp voltage Vn to produce a downward slope that meets the control requirements. This ensures that the change rhythm of the ripple signal is accurately matched with the main control cycle, thereby allowing the entire COT control loop to operate stably.

[0028] It should be noted that when the control loop is in steady state, since the output voltage VOUT = input voltage VIN Duty is the ratio of the fixed on-time Ton of the power transistor to the entire control cycle TSW, i.e., Duty = Fixed on-time Ton / Control cycle TSW; therefore, Control cycle TSW = Fixed on-time Ton Input voltage VIN / Output voltage VOUT.

[0029] Optionally, the specific circuit structure of the ripple generation module 110 described above may include the following two: Continue to refer to Figure 2 The input terminals of the ripple generation module 110 include a supply voltage terminal and a reference voltage terminal. The power supply terminal of the voltage-controlled current source (VCCS) is connected to the supply voltage terminal, the control terminal of the VCCS is connected to the reference voltage terminal, and the output terminal of the VCCS is connected to one end of the first capacitor Cx and one end of the first resistor Rx, respectively. The other end of the first capacitor Cx is grounded, and the other end of the first resistor Rx is connected to one end of the first switch S0, the other end of the first switch S0 is grounded. When the first switch S0 is in the open state, the supply voltage VCC connected to the supply voltage terminal is used to provide operating power to the VCCS, and the reference voltage VREF connected to the reference voltage terminal is used to convert the transconductance Gm of the VCCS into the first current Ix.

[0030] Specifically, the power supply voltage terminal of the ripple generation module 110 is connected to the power supply voltage VCC, providing power support for the normal operation of the voltage-controlled current source VCCS and ensuring its stable output current. The reference voltage terminal is connected to the reference voltage VREF. The voltage-controlled current source VCCS can linearly convert the input reference voltage VREF into a first current Ix of a fixed magnitude based on its own transconductance Gm, i.e., Ix = VREF × Gm. At this time, the first switch S0 is in the open state, and the first current Ix output by the output terminal of the voltage-controlled current source VCCS flows to one end of the first capacitor Cx connected to it, charging the first capacitor Cx that is grounded at the other end; when the first switch S0 is turned on, the first resistor Rx is grounded through the first switch S0, and the first capacitor Cx connected to one end of the first resistor Rx is rapidly discharged through the first resistor Rx. Through this charge and discharge cycle, a first voltage Vx with ripple is continuously generated.

[0031] like Figure 4 As shown, the input terminal of the ripple generation module 110 may further include a setting voltage terminal; when the first switch S0 is in the on state, the setting voltage VSET connected to the setting voltage terminal provides a charging path for the first capacitor Cx through the first resistor Rx. One end of the first switch S0 is connected to the setting voltage terminal, and the other end of the first switch S0 is connected to one end of the first resistor Rx. The other end of the first resistor Rx is connected to one end of the first capacitor Cx and the output terminal of the voltage-controlled current source VCCS, respectively. The other end of the first capacitor Cx is grounded.

[0032] Specifically, when the first switch S0 is in the ON state, the set voltage VSET connected to the set voltage terminal forms a path through the first switch S0, the first resistor Rx, and the first capacitor Cx, allowing the first capacitor Cx to be charged. When the first switch S0 is in the OFF state, the first current Ix output by the voltage-controlled current source VCCS flows to the first capacitor Cx, causing it to discharge. By periodically switching the first switch S0 on and off with the PWM signal, the first capacitor Cx alternately completes the charging and discharging process, thereby generating a rippled first voltage Vx across the first capacitor Cx.

[0033] Optionally, such as Figure 2 and Figure 4As shown, the DC elimination module 120 includes a DC sampling unit (DC sample) and a processing unit. The input terminal of the DC sampling unit (DC sample) is connected to the output terminal of the ripple generation module 110, and is used to sample the first voltage Vx to obtain the DC component Vx_DC. The two input terminals of the processing unit are respectively connected to the output terminal of the ripple generation module 110 and the output terminal of the DC sampling unit (DC sample), and are used to subtract the first voltage Vx from the DC component Vx_DC to eliminate the DC component and obtain the ripple voltage Vripple. That is, the ripple voltage Vripple = Vx_DC – Vx.

[0034] It should be noted that, based on the principle of "charge conservation" during the charging and discharging of the first capacitor Cx, we can obtain: ; After sorting, we can obtain: DC component ; Ripple voltage .

[0035] Optionally, the DC sampling unit (DC sample) is a multi-stage RC low-pass filter circuit. For example... Figure 5 As shown, when the DC sampling unit DC sample is a two-stage RC low-pass filter circuit, the DC sampling unit DC sample may include a second resistor R0, a third resistor R1, a second capacitor C0, and a third capacitor C1; the second resistor R0 and the second capacitor C0 form a first-stage filter, and the third resistor R1 and the third capacitor C1 form a second-stage filter.

[0036] Specifically, in the two-stage RC low-pass filter circuit of the DC sampling unit (DC sample): the first stage filter consists of the second resistor R0 and the second capacitor C0. The first voltage Vx is transmitted through R0 and then grounded and filtered by C0, which initially filters out the high-frequency ripple components in Vx. Subsequently, the signal enters the second stage filter consisting of the third resistor R1 and the third capacitor C1, which further attenuates the residual AC ripple and finally outputs a stable DC component Vx_DC.

[0037] It should be noted that the number of filtering stages in a DC sampling unit is positively correlated with ripple suppression capability but negatively correlated with response speed. Therefore, in practical design, the number of stages can be balanced according to the system's requirements for ripple accuracy and dynamic response. This application does not impose any restrictions on this.

[0038] Optionally, such as Figure 6As shown, the voltage-controlled current source VCCS includes an operational amplifier OP, a first transistor V1, a second transistor V2, and a sampling resistor R2; the inverting input terminal of the operational amplifier OP is connected to the reference voltage terminal, the non-inverting input terminal of the operational amplifier OP is connected to one end of the sampling resistor R2, and the other end of the sampling resistor R2 is grounded; The output terminal of the operational amplifier OP is connected to the gate of the first transistor V1, the drain of the first transistor V1 is connected to one end of the sampling resistor R2, and the source of the first transistor V1 is connected to the power supply voltage terminal; the gate of the second transistor V2 is connected to the gate of the first transistor V1, the source of the second transistor V2 is connected to the power supply voltage terminal, and the drain of the second transistor V2 outputs the first current Ix.

[0039] Specifically, the first transistor V1 and the second transistor V2 form a mirror current source structure. The voltage-controlled current source VCCS can achieve precise conversion from a reference voltage to a fixed current through the negative feedback of the operational amplifier and the mirror current of the transistors in the mirror current source structure. The inverting input of the operational amplifier OP is connected to the reference voltage VREF, and the non-inverting input is connected to the upper end of the sampling resistor R2. By using the negative feedback mechanism to adjust the gate voltage of the first transistor V1, the voltage at the upper end of the sampling resistor R2 is stabilized at a level equal to the reference voltage VREF. At this time, the current in the sampling resistor R2 is I. R2 =VREF / R2, the current I R2 A current will flow through the first transistor V1; and the gates of the first transistor V1 and the second transistor V2 are connected to form a current mirror, therefore the source of the second transistor V2 will output a current similar to I. R2 The first current Ix = VREF / R2 of the same magnitude is used to convert the reference voltage VREF into a fixed first current Ix.

[0040] like Figure 7 As shown in the illustration, this application provides a COT control circuit, including: the aforementioned ripple generation circuit, a phase allocation unit, a main phase COT control loop, and at least one slave phase COT control loop. The output terminal of the ripple generation circuit is connected to the ripple injection terminal of the main phase COT control loop, the output terminal of the main phase COT control loop is connected to the input terminal of the phase allocation unit, and the output terminal of the phase allocation unit is connected to the input terminal of the at least one slave phase COT control loop. The phase allocation unit is used to receive the synchronization signal of the main phase COT control loop and generate a drive signal that is phase-interleaved with the main phase to drive the at least one slave phase COT control loop, thereby realizing current sharing and interleaved operation of multiphase COT control.

[0041] Specifically, the main phase COT control loop is the core of the multiphase COT control circuit. It compares the reference voltage VREF with the output voltage VOUT through the error amplifier EA to generate the control threshold Vc. Simultaneously, it superimposes the ripple voltage Vripple output from the ripple generation circuit with the output voltage VOUT to form a ramp voltage Vn. When the output voltage Vn is less than the control threshold Vc, the comparator CMP triggers the COT generation module 1 to generate a PWM1 signal with a fixed conduction duration. This PWM1 signal is sent to the control logic module 1 to drive the upper and lower power transistors of the main phase to alternately turn on and off, completing the power conversion of the main phase. On the other hand, it is sent to the phase allocation unit. After receiving the synchronous trigger signal of the main phase, the phase allocation unit generates a drive signal that is phase-interleaved with the main phase and sends it to the COT generation module of the slave phase to trigger the generation of a PWM2 signal. This signal is then sent to the control logic module 2 to drive the upper and lower power transistors of the slave phase to turn on and off, thus interleaving the conduction sequence of the power transistors of the main and slave phases, thereby reducing the input and output ripple current and improving the dynamic response speed of the system. Meanwhile, the ripple signal output by the ripple generation circuit is synchronously injected into the main phase control loop to ensure the stability of the single loop, while the interleaved control of the phase distribution unit realizes the current sharing operation of the multiphase system, ultimately enabling the entire multiphase COT control circuit to maintain efficient and stable output under high load scenarios.

[0042] In this embodiment, the ripple generation module actively generates a rippled first voltage by switching the first switch on and off to discharge the first capacitor and charge it via the voltage-controlled current source. This eliminates the need to rely on the high ESR characteristics of the electrolytic capacitor, avoiding the excessive output voltage ripple problem caused by high ESR in traditional electrolytic capacitor solutions, and meeting the low-ripple power supply requirements of precision equipment. Since the DC elimination module samples the first voltage and eliminates the DC component to obtain the ripple voltage, this ripple generation method is not bound to the switch node signal, and therefore is not limited by the number of phases in COT control. It is suitable for both single-phase COT control and multi-phase COT control, broadening the circuit's adaptability. Because the ripple generation is actively controlled by the on / off timing of the voltage-controlled current source, the first capacitor, and the first switch, the ripple parameters can be flexibly adjusted, ensuring the stability of the COT control loop and solving the loop instability problem of traditional solutions. Since the circuit of this application consists of a ripple generation module and a DC elimination module, it has no complex external components, has a simple overall structure, occupies a small chip area, and is easy to integrate into a DC-DC converter chip, which can reduce hardware costs and design complexity.

[0043] 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 ripple generation circuit, characterized in that, include: Ripple generation module and DC cancellation module; The ripple generation module includes a first capacitor, a first resistor, a first switch, a voltage-controlled current source, and a reference voltage; When the first switch is in the on state, the first capacitor discharges through the first resistor. When the first switch is in the off state, the reference voltage controls the voltage-controlled current source to generate a first current, and charges the first capacitor through the first current to generate a first voltage with ripple. The DC elimination module is used to sample the first voltage to obtain a DC component, and to obtain a ripple voltage by eliminating the DC component.

2. The ripple generation circuit according to claim 1, characterized in that, The input terminals of the ripple generation module include a power supply voltage terminal and a reference voltage terminal; When the first switch is in the open state, the supply voltage connected to the supply voltage terminal is used to provide working power for the voltage-controlled current source, and the reference voltage connected to the reference voltage terminal is used to convert the voltage-controlled current source into the first current according to the transconductance of the voltage-controlled current source.

3. The ripple generation circuit according to claim 2, characterized in that, The power supply terminal of the voltage-controlled current source is connected to the power supply voltage terminal, the control terminal of the voltage-controlled current source is connected to the reference voltage terminal, the output terminal of the voltage-controlled current source is connected to one end of the first capacitor and one end of the first resistor respectively, the other end of the first capacitor is grounded, the other end of the first resistor is connected to one end of the first switch, and the other end of the first switch is grounded.

4. The ripple generation circuit according to claim 2, characterized in that, The input terminal of the ripple generation module also includes a setting voltage terminal; When the first switch is in the ON state, the set voltage connected to the set voltage terminal provides a charging path for the first capacitor through the first resistor.

5. The ripple generation circuit according to claim 4, characterized in that, One end of the first switch is connected to the set voltage terminal, the other end of the first switch is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the first capacitor and the output terminal of the voltage-controlled current source, and the other end of the first capacitor is grounded.

6. The ripple generation circuit according to any one of claims 1-5, characterized in that, The voltage-controlled current source includes an operational amplifier, a first transistor, a second transistor, and a sampling resistor; The inverting input terminal of the operational amplifier is connected to the reference voltage terminal, the non-inverting input terminal of the operational amplifier is connected to one end of the sampling resistor, and the other end of the sampling resistor is grounded. The output terminal of the operational amplifier is connected to the gate of the first transistor, the drain of the first transistor is connected to one end of the sampling resistor, and the source of the first transistor is connected to the power supply voltage terminal. The gate of the second transistor is connected to the gate of the first transistor, the source of the second transistor is connected to the power supply voltage terminal, and the drain of the second transistor outputs the first current.

7. The ripple generation circuit according to claim 1, characterized in that, The DC cancellation module includes a DC sampling unit and a processing unit; The input terminal of the DC sampling unit is connected to the output terminal of the ripple generation module, and is used to perform DC sampling on the first voltage to obtain the DC component; The two input terminals of the arithmetic unit are respectively connected to the output terminal of the ripple generation module and the output terminal of the DC sampling unit, and are used to subtract the first voltage from the DC component to obtain the ripple voltage after eliminating the DC component.

8. The ripple generation circuit according to claim 7, characterized in that, The DC sampling unit is a multi-stage RC low-pass filter circuit.

9. The ripple generation circuit according to claim 8, characterized in that, The DC sampling unit includes a second resistor, a third resistor, a second capacitor, and a third capacitor; the second resistor and the second capacitor form a first-stage filter, and the third resistor and the third capacitor form a second-stage filter.

10. A COT control circuit, characterized in that, include: The ripple generation circuit, phase allocation unit, main phase COT control loop, and at least one slave phase COT control loop as described in any one of claims 1 to 9; The output terminal of the ripple generation circuit is connected to the ripple injection terminal of the main phase COT control loop, the output terminal of the main phase COT control loop is connected to the input terminal of the phase allocation unit, and the output terminal of the phase allocation unit is connected to the input terminal of the at least one slave phase COT control loop. The phase allocation unit is used to receive the synchronization signal of the main phase COT control loop and generate a drive signal that is phase-interleaved with the main phase to drive the at least one slave phase COT control loop, thereby realizing the current sharing and interleaved operation of multi-phase COT control.

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