A direct-current-direct-current conversion circuit and a power management chip

Abstract

The application provides a DC-DC conversion circuit and a power management chip, wherein the DC-DC conversion circuit comprises a voltage conversion module, a sampling processing module, a switch module, a switch control module and a signal control module. The voltage conversion module and the switch module are connected to an input voltage; the sampling processing module is connected to an output voltage and a reference voltage and obtains a first current; the switch control module is connected to the input voltage and the controlled end of the switch module, and is used for applying a target voltage greater than the input voltage to the controlled end, so that the switch module outputs a second current; the signal control module is connected to the first and second voltage signals, and adjusts the output voltage of the voltage conversion module according to the first and second voltage signals. Wherein, the first voltage signal is a signal generated according to the second current and the first current. Through the application, when the duration of the high-bit control signal output by the pulse width modulation controller in the DC-DC conversion circuit is short, the normal operation of the circuit can be ensured.

Description

Technical Field

[0001] This application relates to the field of switching power supply technology, and in particular to a DC-DC conversion circuit and a power management chip. Background Technology

[0002] A DC-DC converter circuit is an electrical energy conversion circuit that transforms direct current (DC) at one voltage into DC at another voltage. In existing technologies, the voltage conversion module in the DC-DC converter circuit is controlled through output voltage sampling circuits and current sampling circuits.

[0003] To avoid the problems of complex structure, large size, and distorted current sampling values ​​in the current sampling circuit of the DC-DC converter, the relevant technology uses a switching transistor connected in series between the comparator and the input voltage in the control circuit of the DC-DC converter to replace the original current sampling circuit. This switching transistor is turned on when the pulse width modulation controller of the DC-DC converter outputs a high-level control signal.

[0004] However, due to the parasitic capacitance of the switching transistor, when the duration of the high-order control signal output by the pulse width modulation controller in the DC-DC converter circuit is short, i.e., the duty cycle is small, the charging current of the parasitic capacitance in the switching transistor will affect the input signal at the inverting input terminal of the comparator in the control loop of the DC-DC converter circuit, causing the DC-DC converter circuit to malfunction. Summary of the Invention

[0005] This application provides a DC-DC conversion circuit and a power management chip that can ensure normal operation of the circuit when the duration of the high-level control signal output by the pulse width modulation controller in the DC-DC conversion circuit is short.

[0006] In a first aspect, this application provides a DC-DC conversion circuit, comprising:

[0007] A voltage conversion module, wherein the first input terminal of the voltage conversion module is connected to an input voltage, and the voltage conversion module is used to convert the input voltage into an output voltage and output it through the first output terminal of the voltage conversion module;

[0008] A sampling processing module is provided, wherein the first input terminal of the sampling processing module is connected to the output voltage, and the second input terminal of the sampling processing module is connected to a reference voltage, for sampling the output voltage to obtain a feedback voltage, and obtaining a first current based on the feedback voltage and the reference voltage;

[0009] A switching module, wherein the first terminal of the switching module is connected to the input voltage;

[0010] A switch control module, wherein the input terminal of the switch control module is connected to the input voltage, and the output terminal of the switch control module is connected to the controlled terminal of the switch module, for applying a target voltage greater than the input voltage to the controlled terminal of the switch module, causing the switch module to output a second current; and

[0011] A signal control module has a first input terminal connected to the second terminal of the switching module and the output terminal of the sampling processing module, used to receive a first voltage signal, wherein the first voltage signal is a signal generated based on the second current and the first current; the second input terminal of the signal control module is used to receive a second voltage signal at the switching node of the voltage conversion module; the output terminal of the signal control module is connected to the control terminal of the voltage conversion module, used to adjust the output voltage of the voltage conversion module based on the first voltage signal and the second voltage signal.

[0012] The proposed solution employs a switch control module on the switch module, directly applying a target voltage greater than the input voltage to the controlled terminal of the switch module, thereby ensuring continuous conduction of the switch module. This solution replaces the method used in related technologies that employs a high-level control signal output from a pulse width modulation controller to turn on the switching transistor. Because the switch control module can generate a target voltage greater than the input voltage to power the switch module, keeping the switching transistor operating at a constant voltage, there is no current charging the parasitic capacitor. This avoids the problem of the first voltage signal being affected by the charging current of the parasitic capacitor, which could cause the circuit to malfunction.

[0013] In conjunction with the first aspect, in some possible implementations, the switch control module includes a voltage source, a first capacitor, a second capacitor, a first oscillation module, and a switch assembly. One common terminal of the first capacitor and the second capacitor connected in parallel is connected to the positive terminal of the voltage source, and the other common terminal is connected to the negative terminal of the voltage source. The second plate of the second capacitor is connected to the input voltage, and the first plate of the second capacitor is connected to the controlled terminal of the switch module.

[0014] The first oscillation module is used to control the connection and disconnection between the voltage source and the first capacitor, and between the first capacitor and the second capacitor, by controlling the switching component to turn on or off.

[0015] In combination with the first aspect and the above implementation methods, in some possible implementations, the switching component includes:

[0016] A first switch and a second switch, wherein the first terminal of the first switch is connected to the positive terminal of the voltage source, and the first terminal of the second switch is connected to the negative terminal of the voltage source;

[0017] A third switch and a fourth switch, wherein the first end of the third switch is connected to the second end of the first switch and the first plate of the first capacitor; and the first end of the fourth switch is connected to the second end of the second switch and the second plate of the first capacitor.

[0018] The first plate of the second capacitor is connected to the second terminal of the third switch; the second plate of the second capacitor is connected to the second terminal of the fourth switch.

[0019] The first output terminal of the first oscillation module is connected to the third terminal of the first switch and the third terminal of the second switch; the second output terminal of the first oscillation module is connected to the third terminal of the third switch and the third terminal of the fourth switch.

[0020] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the switching module includes a plurality of first switching transistors connected in series;

[0021] The first terminal of the first of the plurality of first switching transistors is connected to the input voltage, and the second terminal of the last of the plurality of first switching transistors is connected to the first input terminal of the signal control module and the output terminal of the sampling processing module.

[0022] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the first switching transistor is an NMOS transistor.

[0023] In combination with the first aspect and the above implementation methods, in some possible implementations, the signal control module includes:

[0024] The comparison module has its inverting input connected to the output of the sampling processing module and the second terminal of the switching module, and its non-inverting input connected to the switching node of the voltage conversion module, for generating a pulse width modulation signal based on the first voltage signal and the second voltage signal;

[0025] A pulse width modulation (PWM) controller is provided, wherein the input terminal of the PWM controller is connected to the output terminal of the comparison module for receiving the PWM signal; the first output terminal of the PWM controller is connected to the first control terminal of the voltage conversion module, and the second output terminal of the PWM controller is connected to the second control terminal of the voltage conversion module; the PWM controller is used to generate a first control signal and a second control signal based on the PWM signal.

[0026] In combination with the first aspect and the above implementation methods, in some possible implementations, the voltage conversion module includes:

[0027] The upper tube has its first end connected to the input voltage, its second end connected to the switching node, and its controlled end connected to the first control signal.

[0028] The lower tube is connected to the second control signal at its controlled end, the first end of the lower tube is connected to the switch node, and the second end of the lower tube is grounded.

[0029] The ratio of the on-resistance of the switch module to the on-resistance of the upper transistor is K, and the value of K ranges from 10 to 100000.

[0030] In combination with the first aspect and the above implementation methods, in some possible implementations, the sampling processing module includes:

[0031] An output sampling module, wherein the input terminal of the output sampling module is connected to the first output terminal of the voltage conversion module, is used to sample the output voltage and output a feedback voltage;

[0032] An error amplifier is provided, wherein the inverting input of the error amplifier is connected to the output of the output sampling module to receive the feedback voltage, the non-inverting input of the error amplifier is used to input the reference voltage, and the output of the error amplifier is used to output the error amplification signal.

[0033] The subtractor has its first input terminal connected to the output terminal of the error amplifier for receiving the error amplification signal, and its second input terminal for receiving the ramp signal. The output terminal of the subtractor is connected to the second terminal of the switching module and the inverting input terminal of the comparison module for outputting the first current.

[0034] In conjunction with the first aspect and the above implementation methods, in some possible implementations, the sampling processing module further includes:

[0035] The second oscillation module has its output connected to the first input of the subtractor, and is used to input the ramp signal into the subtractor.

[0036] Secondly, this application also provides a power management chip, including the DC-DC conversion circuit described in any of the first aspects above. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of a DC-DC conversion circuit provided in an embodiment of this application;

[0038] Figure 2 yes Figure 1 An exemplary circuit diagram of a medium voltage conversion module;

[0039] Figure 3 yes Figure 1 A schematic diagram of an exemplary DC-DC converter circuit;

[0040] Figure 4 yes Figure 3 An exemplary circuit diagram of the switch control module.

[0041] The annotations in the attached figures are explained as follows:

[0042] 100—Voltage conversion module; Q2—Upper transistor; Q3—Lower transistor; L—Inductor; P—Switching node;

[0043] 200—Sampling processing module; 210—Output sampling module; 220—Error amplifier; 230—Subtractor; 240—Second oscillation module;

[0044] 300—Switch module; Q1—First switch transistor;

[0045] 400—Signal control module; 410—Comparison module; 420—Pulse width modulation controller;

[0046] 500—Switch control module; 510—First oscillation module; E—Voltage source; S1—First switch; S2—Second switch; S3—Third switch; S4—Fourth switch; C1—First capacitor; C2—Second capacitor;

[0047] VIN—Input voltage; VO—Output voltage; Vfb—Feedback voltage; Vref—Reference voltage; EAO—Error amplification signal; Ramp—Ramp signal;

[0048] E2—First voltage signal; SW—Second voltage signal; PWMO—Pulse width modulation signal;

[0049] DH—First control signal; DL—Second control signal. Detailed Implementation

[0050] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0051] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0052] The relevant technology replaces the original current sampling circuit in the DC-DC converter circuit by connecting a switching transistor in series between the comparator and the input voltage in the control loop of the DC-DC converter circuit. This switching transistor is turned on when the pulse width modulation controller of the DC-DC converter circuit outputs a high-level control signal.

[0053] However, due to the parasitic capacitance of the switching transistor, when the duration of the high-order control signal output by the pulse width modulation controller in the DC-DC converter circuit is short, i.e., the duty cycle is small, the charging current of the parasitic capacitance in the switching transistor will affect the input signal at the inverting input terminal of the comparator in the control loop of the DC-DC converter circuit, causing the DC-DC converter circuit to malfunction.

[0054] To address the aforementioned technical problems, embodiments of this application provide a DC-DC conversion circuit and a power management chip.

[0055] The following is a detailed description of a DC-DC conversion circuit provided in the embodiments of this application, with reference to the accompanying drawings.

[0056] First, please refer to Figure 1 , Figure 2 and Figure 3 The first aspect of this application provides a DC-DC conversion circuit, which includes a voltage conversion module 100, a sampling processing module 200, a switching module 300, and a signal control module 400.

[0057] The first input terminal of the voltage conversion module 100 is connected to the input voltage VIN. The voltage conversion module 100 is used to convert the input voltage VIN into an output voltage VO, which is then output through the first output terminal of the voltage conversion module 100. Figure 2 As shown, in one possible implementation, the voltage conversion module 100 may include an upper transistor Q2 and a lower transistor Q3. The first terminal of the upper transistor Q2 is connected to the input voltage VIN, the second terminal of the upper transistor Q2 is connected to the switching node P, and the controlled terminal of the upper transistor Q2 is connected to the first control signal DH. The controlled terminal of the lower transistor Q3 is connected to the second control signal DL, the first terminal of the lower transistor Q3 is connected to the switching node P, and the second terminal of the lower transistor Q3 is grounded.

[0058] The first input terminal of the sampling processing module 200 is connected to the output voltage VO, and the second input terminal is connected to the reference voltage Vref. This is used to sample the output voltage VO to obtain the feedback voltage Vfb, and to obtain the first current based on the feedback voltage Vfb and the reference voltage Vref. For example... Figure 3 As shown, in one possible implementation, the sampling processing module 200 may include an output sampling module 210, an error amplifier 220, and a subtractor 230. The input terminal of the output sampling module 210 is connected to the first output terminal of the voltage conversion module 100, used to sample the output voltage VO and output a feedback voltage Vfb. The inverting input terminal of the error amplifier 220 is connected to the output terminal of the output sampling module 210, used to input the feedback voltage Vfb, and the non-inverting input terminal of the error amplifier 220 is used to input a reference voltage Vref. The error amplifier 220 generates an error amplification signal EAO based on the reference voltage Vref and the feedback voltage Vfb, and outputs the error amplification signal EAO to the subtractor 230. The reference voltage signal Vref can be a bandgap reference voltage or a voltage division value of the bandgap reference voltage; this application does not specifically limit its application.

[0059] The first input terminal of subtractor 230 is connected to the output terminal of error amplifier 220, and is used to input the error amplification signal EAO. The second input terminal of subtractor 230 is used to input the ramp signal Ramp. Subtractor 230 generates a first current based on the ramp signal Ramp and the error amplification signal EAO. The output terminal of subtractor 230 is connected to the second terminal of switch module 300 and the inverting input terminal of comparator module 410, and is used to output the first current. In one example, sampling processing module 200 may further include a second oscillation module 240, which is used to generate the ramp signal Ramp. Specifically, the output terminal of the second oscillation module 240 is connected to the first input terminal of subtractor 230, and is used to input the ramp signal Ramp into subtractor 230.

[0060] The first terminal of the switching module 300 is connected to the input voltage VIN, and the second terminal of the switching module 300 is connected to the first input terminal of the signal control module 400; the switching module 300 outputs a second current when it is turned on. (See also...) Figure 3The switching module 300 may include multiple first switching transistors Q1 connected in series. The first terminal of the first first switching transistor Q1 is connected to the input voltage VIN, and the second terminal of the last first switching transistor Q1 is connected to the first input terminal of the signal control module 400 and the output terminal of the sampling processing module 200. The first switching transistors Q1 of the switching module 300 and the upper transistor Q2 of the voltage conversion module 100 should be of the same type, but with different aspect ratios; for example, the aspect ratio of the upper transistor Q2 is larger than that of the first switching transistor Q1. Both the first switching transistors Q1 and the upper transistor Q2 can be NMOS transistors. When the first switching transistor is an NMOS transistor, the first terminal of the first NMOS transistor is connected to the input voltage VIN, and the second terminal of the last NMOS transistor is connected to the first input terminal of the signal control module 400 and the output terminal of the sampling processing module 200.

[0061] The first input terminal of the signal control module 400 is connected to the second terminal of the switch module 300 and the output terminal of the sampling processing module 200, and is used to receive the first voltage signal E2, wherein the first voltage signal E2 is a signal generated based on the second current and the first current; the second input terminal of the signal control module 400 is used to receive the second voltage signal SW at the switch node P of the voltage conversion module 100; the output terminal of the signal control module 400 is connected to the control terminal of the voltage conversion module 100, and is used to adjust the output voltage VO of the voltage conversion module 100 according to the first voltage signal E2 and the second voltage signal SW. Figure 3As shown, in one possible implementation, the signal control module 400 may include a comparison module 410 and a pulse width modulation controller 420. The inverting input of the comparison module 410 is connected to the output of the sampling processing module 200 and the second terminal of the switching module 300, and the non-inverting input of the comparison module 410 is connected to the switching node P of the voltage conversion module 100. Since the voltage at the switching node P of the voltage conversion module 100 is the second voltage signal SW, the comparison module 410 can generate a pulse width modulation signal PWMO based on the first voltage signal E2 and the second voltage signal SW. The input terminal of the pulse width modulation controller 420 is connected to the output terminal of the comparator module 410 to receive the pulse width modulation signal PWMO. The first output terminal of the pulse width modulation controller 420 is connected to the first control terminal of the voltage conversion module 100, and the second output terminal of the pulse width modulation controller 420 is connected to the second control terminal of the voltage conversion module 100. The pulse width modulation controller 420 is used to generate a first control signal DH and a second control signal DL according to the pulse width modulation signal PWMO, and drive the power switch in the voltage conversion module 100 to turn on and off through the first control signal DH and the second control signal DL. Specifically, the first control signal DH output by the first output terminal of the signal control module 400 is a high-side duty cycle control signal, and the second control signal DL output by the signal control module 400 is a low-side duty cycle control signal. The first control signal DH and the second control signal DL are used to drive the upper transistor Q2 and the lower transistor Q3 in the voltage conversion module 100 to turn on or off, so as to convert the input voltage VIN into the output voltage VO under the on or off state of the upper transistor Q2 and the lower transistor Q3.

[0062] It should be noted that the subtractor 230 is used to adjust the voltage V of the ramp signal Ramp. Ramp And the voltage V of the error amplification signal EAO EAO Perform the difference to obtain the voltage difference signal V. EAO -V Ramp The voltage difference signal is processed to obtain a current signal, which is the first current. Let the resistor in the subtractor 230 be R1, then the first current is (V... EAO -V Ramp ) / R1.

[0063] The switching module 300 can be considered as a resistor during operation. To minimize the voltage difference between chips (circuits), the resistance value R of the switching module 300 is... Q It can be connected to the on-resistance R of the upper transistor Q2. on To a preset ratio, i.e. R Q / R on =K, where R is the on-resistance of the switch module 300. Q The on-resistance R of the upper transistor Q2 onThe ratio is K, and the value of K can range from 10 to 100000.

[0064] When the voltage V of the first voltage signal E2 input to the inverting input terminal of the comparator module 410 is... E2 The voltage V of the second voltage signal SW input to the non-inverting input terminal is greater than the voltage V of the second voltage signal SW input to the non-inverting input terminal. SW When the pulse width modulation signal PWMO is low, the voltage V of the first voltage signal E2 input to the inverting input terminal is low. E2 The voltage V is less than the voltage V of the second voltage signal SW input to the non-inverting input terminal. SW At this time, the pulse width modulation signal PWMO is at a high level; that is, the voltage V of the first voltage signal E2 input to the inverting input terminal of the pulse width modulation signal PWMO output by the comparator module 410 is high. E2 The voltage V is equal to the voltage V of the second voltage signal SW input to the non-inverting input terminal. SW Flip it over.

[0065] See Figure 3 Because the voltage V of the first voltage signal E2 E2 =VIN-((V EAO -V Ramp ) / R1)×R Q The voltage V of the second voltage signal SW SW =VIN-I L ×R on , among which, I L This is the current in the inductor L in the voltage conversion module 100. Therefore, the comparator module 410 compares V. E2 With V SW The size, that is, comparing VIN-((V EAO -V Ramp ) / R1)×R Q With VIN-I L ×R on The size of V is compared by simplifying the above equation. EAO With V Ramp +I L The size of ×R1 / K.

[0066] It can be seen that the voltage V of the first voltage signal E2 of the comparison module 410 E2 The voltage V of the second voltage signal SW SW During comparison, no current sampling signal is introduced; therefore, it is not limited by the performance of existing current sampling circuits in related technologies. Furthermore, different resistance values ​​for the switching module 300 and the upper transistor Q2 can be selected, and the resistance can be adjusted by... Q / R on The ratio K is used to adjust the pulse width modulation signal PWMO.

[0067] In this DC-DC converter circuit, when the feedback voltage Vfb is lower than the reference voltage Vref, the voltage V of the error amplification signal EAO... EAO This will increase, causing the first current output by the subtractor 230 to increase, which in turn will increase the voltage V of the first voltage signal E2. E2 As the voltage decreases, the duty cycle of the pulse width modulation signal PWMO output by the comparison module 410 will increase, leading to an increase in the output voltage VO output from the first output terminal of the voltage conversion module 100, which will raise the value of the feedback voltage Vfb. When the feedback voltage Vfb is higher than the reference voltage Vref, the voltage V of the error amplification signal EAO will increase. EAO This will decrease, causing the current of the first current output by the subtractor 230 to decrease, which in turn will cause the voltage V of the first voltage signal E2 to decrease. E2 As the voltage increases, the duty cycle of the pulse width modulation signal PWMO output by the comparison module 210 will decrease, resulting in a decrease in the output voltage VO output from the first output terminal of the voltage conversion module 100, which will lower the voltage value of Vfb. It can be seen that the above feedback loop forms negative feedback. When this negative feedback loop is stable, the feedback voltage Vfb equals the reference voltage Vref, thus allowing precise control of the feedback voltage Vfb, and consequently, precise control of the output voltage VO.

[0068] It should be noted that, for example Figure 1 and Figure 3 As shown, the DC-DC conversion circuit proposed in this application also includes a switch control module 500. The input terminal of the switch control module 500 is connected to the input voltage VIN, and the output terminal of the switch control module 500 is connected to the controlled terminal of the switch module 300. This allows the switch module 300 to apply a target voltage greater than the input voltage VIN to the controlled terminal, causing the switch module 300 to output a second current. The minimum difference between the target voltage and the input voltage VIN is the turn-on voltage (i.e., threshold voltage) of the switch module 300; for example, the turn-on voltage of an NMOS transistor can be 2V. The maximum difference between the target voltage and the input voltage VIN can be 10V. That is, for an NMOS transistor, the range of the difference between the target voltage and the input voltage VIN can be 2V to 10V. It is understood that designers can flexibly select the difference voltage within the range of the turn-on voltage and 10V according to actual conditions.

[0069] The technical concept of the technical solution in this application will be described in detail below.

[0070] In related technologies, a switching transistor is connected in series between the comparator and the input voltage in the control loop of the DC-DC converter circuit. This switching transistor is turned on when the pulse width modulation controller of the DC-DC converter circuit outputs a high-level control signal. The following explanation uses an NMOS transistor as an example, i.e., the switching module 300.

[0071] Because the NMOS transistor in the switching module 300 has parasitic capacitances Cgd (the capacitance between the gate and drain) and Cgs (the capacitance between the gate and source), in the DC-DC conversion circuit of related technologies, when the pulse width modulation controller outputs a high-order control signal to turn on the NMOS transistor, see [reference needed]. Figure 3 When the first control signal DH rises from a low level to a high level, the parasitic capacitances Cgd and Cgs need to be charged. This charging current will cause the voltage V of the first voltage signal to rise. E2 The voltage increases beyond the input voltage VIN, thereby causing the voltage V of the first voltage signal E2 to rise. E2 Abnormal. The charging current becomes 0 only after the parasitic capacitances Cgd and Cgs are fully charged. At this point, the voltage V of the first voltage signal E2... E2 The current supplied by subtractor 230 gradually returned to normal. Furthermore, because the low-power subtractor provides relatively small current, the voltage V of the first voltage signal E2 decreased. E2 Recovery time is relatively slow.

[0072] Especially when the duty cycle of the first control signal DH is relatively small, the corresponding input voltage VIN is generally larger and the output voltage VO is smaller. For example, if the input voltage VIN is 18V and the output voltage is 1V, the normally operating high-side switch, i.e., the first switching transistor Q1, has a short conduction time, meaning the time the first control signal DH is high is short. If the time the first control signal DH is high is shorter than the voltage V of the first voltage signal E2... E2 If the time required for the DC-DC converter to recover from an incorrect value to a correct value is too short, the DC-DC converter circuit will malfunction and fail to operate properly. In other words, if the duration of the high-order control signal output by the pulse width modulation controller in the DC-DC converter circuit of the relevant technology is too short, the circuit is prone to failure.

[0073] To address this issue, the proposed solution involves incorporating a switch control module 500 onto the switch module 300. This module directly applies a target voltage greater than the input voltage VIN to the controlled terminal of the switch module 300, thereby ensuring the continuous operation of the switch module 300. This solution replaces the method used in related technologies, which employs a high-order control signal output from a pulse width modulation controller to turn on the switching transistor. Because the switch control module 500 can generate a target voltage greater than the input voltage VIN to power the switch module 300, the switching transistor of the switch module 300 maintains a constant voltage operation. Therefore, there is no current charging the parasitic capacitances Cgd and Cgs, and the voltage V of the first voltage signal E2 is avoided. E2The problem of the circuit malfunctioning due to the charging current of parasitic capacitors Cgd and Cgs is addressed. In other words, the switching transistor in the switching module 300 of this solution is no longer associated with the first control signal DH output by the pulse width modulation controller. Even if the first switching transistor Q1 has a short on-time, i.e., the first control signal DH is high for a short period, the DC-DC conversion circuit can still function normally.

[0074] Understandably, the circuit structure of the switch control module 500 can have multiple forms. In one possible implementation, such as... Figure 4 As shown, the switch control module 500 may include a voltage source E, a first capacitor C1, a second capacitor C2, a first oscillation module 510, and a switch assembly. One common terminal of the first capacitor C1 and the second capacitor C2 connected in parallel is connected to the positive terminal of the voltage source E, and the other common terminal is connected to the negative terminal of the voltage source E. The second plate of the second capacitor C2 is connected to the input voltage VIN, and the first plate of the second capacitor C2 is connected to the controlled terminal of the switch module 300. The first oscillation module 510 is used to control the on / off state between the voltage source E and the first capacitor C1, and between the first capacitor C1 and the second capacitor C2, by controlling the on / off state of the switch assembly.

[0075] The switching assembly may include a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4. The first terminal of the first switch S1 is connected to the positive terminal of the voltage source E; the first terminal of the second switch S2 is connected to the negative terminal of the voltage source E; the first terminal of the third switch S3 is connected to the second terminal of the first switch S1 and the first plate of the first capacitor C1; the first terminal of the fourth switch S4 is connected to the second terminal of the second switch S2 and the second plate of the first capacitor C1; the first plate of the second capacitor C2 is connected to the second terminal of the third switch S3; the second plate of the second capacitor C2 is connected to the second terminal of the fourth switch S4; the first output terminal of the first oscillation module 510 is connected to the third terminal of the first switch S1 and the third terminal of the second switch S2; the second output terminal of the first oscillation module 510 is connected to the third terminal of the third switch S3 and the third terminal of the fourth switch S4.

[0076] It should be noted that the first output terminal and the second output terminal of the first oscillation module 510 generate two clock signals CK1 and CK2 that are out of phase with each other.

[0077] When clock signal CK1 is high and clock signal CK2 is low, the first switch S1 and the second switch S2 are turned on, and the two plates of the first capacitor C1 are charged by voltage source E to its charging voltage. For example, the charging voltage of voltage source E can be 5V, that is, the two plates of the first capacitor C1 are charged to 5V.

[0078] When clock signal CK1 is low, clock signal CK2 is high, and the third switch S3 and the fourth switch S4 are turned on. The lower plate of the first capacitor C1, i.e., the second plate, is connected to the input voltage VIN. At this time, the voltage of the upper plate of the first capacitor C1, i.e., the first plate, is equal to the input voltage VIN + the charging voltage (because the voltage between the two plates of the first capacitor C1 remains unchanged). Furthermore, the turning on of the third switch S3 and the fourth switch S4 also causes the first capacitor C1 to charge the second capacitor C2. Therefore, the two plates of the second capacitor C2 are also charged to the charging voltage. Finally, the voltage of the upper plate of the second capacitor C2 connected to the controlled terminal of the switch module 300, i.e., the first plate, is equal to VIN + the charging voltage, for example, equal to VIN + 5V.

[0079] Therefore, the switch control module 500 can apply a target voltage greater than the input voltage VIN to the controlled terminal of the switch module 300, so that the switch module 300 continuously outputs a second current.

[0080] Finally, a second aspect of this application also proposes a power management chip that includes the DC-DC conversion circuit described in any of the above alternative embodiments. Since the DC-DC conversion circuit has been described in detail above, it will not be repeated here.

[0081] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this application, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0082] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A DC-DC converter circuit, characterized in that, include: A voltage conversion module (100) is provided, wherein the first input terminal of the voltage conversion module (100) is connected to an input voltage (VIN), and the voltage conversion module (100) is used to convert the input voltage (VIN) into an output voltage (VO) and output it through the first output terminal of the voltage conversion module (100); A sampling processing module (200) is provided, wherein the first input terminal of the sampling processing module (200) is connected to the output voltage (VO), and the second input terminal of the sampling processing module (200) is connected to the reference voltage (Vref), for sampling the output voltage (VO) to obtain a feedback voltage (Vfb), and obtaining a first current based on the feedback voltage (Vfb) and the reference voltage (Vref); A switching module (300), the first terminal of which is connected to the input voltage (VIN); A switch control module (500) is provided, wherein the input terminal of the switch control module (500) is connected to the input voltage (VIN), and the output terminal of the switch control module (500) is connected to the controlled terminal of the switch module (300). The switch control module (500) is used to apply a target voltage greater than the input voltage (VIN) to the controlled terminal of the switch module (300), so that the switch module (300) outputs a second current. as well as A signal control module (400) has a first input terminal connected to the second terminal of the switch module (300) and the output terminal of the sampling processing module (200) for receiving a first voltage signal (E2), wherein the first voltage signal (E2) is a signal generated based on the second current and the first current; The second input terminal of the signal control module (400) is used to connect to the second voltage signal (SW) at the switching node (P) of the voltage conversion module (100); the output terminal of the signal control module (400) is connected to the control terminal of the voltage conversion module (100) and is used to adjust the output voltage (VO) of the voltage conversion module (100) according to the first voltage signal (E2) and the second voltage signal (SW).

2. The DC-DC conversion circuit according to claim 1, characterized in that, The switch control module (500) includes a voltage source (E), a first capacitor (C1), a second capacitor (C2), a first oscillation module (510), and a switch assembly. One common terminal of the first capacitor (C1) and the second capacitor (C2) connected in parallel is connected to the positive terminal of the voltage source (E), and the other common terminal is connected to the negative terminal of the voltage source (E). The second plate of the second capacitor (C2) is connected to the input voltage (VIN), and the first plate of the second capacitor (C2) is connected to the controlled terminal of the switch module (300). The first oscillation module (510) is used to control the on / off state between the voltage source (E) and the first capacitor (C1), and between the first capacitor (C1) and the second capacitor (C2) by controlling the on / off state of the switching assembly.

3. The DC-DC conversion circuit according to claim 2, characterized in that, The switching assembly includes: A first switch (S1) and a second switch (S2), wherein the first terminal of the first switch (S1) is connected to the positive terminal of the voltage source (E), and the first terminal of the second switch (S2) is connected to the negative terminal of the voltage source (E); The third switch (S3) and the fourth switch (S4) are connected as follows: the first end of the third switch (S3) is connected to the second end of the first switch (S1) and the first plate of the first capacitor (C1); the first end of the fourth switch (S4) is connected to the second end of the second switch (S2) and the second plate of the first capacitor (C1). The first plate of the second capacitor (C2) is connected to the second terminal of the third switch (S3); the second plate of the second capacitor (C2) is connected to the second terminal of the fourth switch (S4); The first output terminal of the first oscillation module (510) is connected to the third terminal of the first switch (S1) and the third terminal of the second switch (S2); the second output terminal of the first oscillation module (510) is connected to the third terminal of the third switch (S3) and the third terminal of the fourth switch (S4).

4. The DC-DC conversion circuit according to claim 1, characterized in that, The switching module (300) includes a plurality of first switching transistors (Q1) connected in series; The first terminal of the first of the plurality of first switching transistors (Q1) is connected to the input voltage (VIN), and the second terminal of the last of the plurality of first switching transistors (Q1) is connected to the first input terminal of the signal control module (400) and the output terminal of the sampling processing module (200).

5. The DC-DC conversion circuit as described in claim 4, characterized in that, The first switch (Q1) is an NMOS transistor.

6. The DC-DC conversion circuit according to any one of claims 1 to 5, characterized in that, The signal control module (400) includes: A comparison module (410) is provided, wherein the inverting input terminal of the comparison module (410) is connected to the output terminal of the sampling processing module (200) and the second terminal of the switching module (300), and the non-inverting input terminal of the comparison module (410) is connected to the switching node (P) of the voltage conversion module (100), for generating a pulse width modulation signal (PWMO) based on the first voltage signal (E2) and the second voltage signal (SW); A pulse width modulation controller (420) is provided, the input of which is connected to the output of the comparison module (410) for receiving the pulse width modulation signal (PWMO); the first output of the pulse width modulation controller (420) is connected to the first control terminal of the voltage conversion module (100), and the second output of the pulse width modulation controller (420) is connected to the second control terminal of the voltage conversion module (100). The pulse width modulation controller (420) is used to generate a first control signal (DH) and a second control signal (DL) based on the pulse width modulation signal (PWMO).

7. The DC-DC conversion circuit according to claim 6, characterized in that, The voltage conversion module (100) includes: The upper transistor (Q2) has its first terminal connected to the input voltage (VIN), its second terminal connected to the switching node (P), and its controlled terminal connected to the first control signal (DH). The lower tube (Q3) has its controlled terminal connected to the second control signal (DL), its first terminal connected to the switch node (P), and its second terminal grounded. The ratio of the on-resistance of the switch module (300) to the on-resistance of the upper transistor (Q2) is K, and the value of K ranges from 10 to 100000.

8. The DC-DC conversion circuit according to claim 6, characterized in that, The sampling processing module (200) includes: An output sampling module (210) is provided, the input terminal of which is connected to the first output terminal of the voltage conversion module (100) for sampling the output voltage (VO) and outputting a feedback voltage (Vfb). An error amplifier (220) is provided, the inverting input of which is connected to the output of the output sampling module (210) and used to input the feedback voltage (Vfb); the non-inverting input of which is used to input the reference voltage (Vref); and the output of which is used to output the error amplification signal (EAO). The subtractor (230) has its first input terminal connected to the output terminal of the error amplifier (220) for inputting the error amplification signal (EAO), and its second input terminal for inputting the ramp signal (Ramp); the output terminal of the subtractor (230) is connected to the second terminal of the switch module (300) and the inverting input terminal of the comparison module (410) for outputting the first current.

9. The DC-DC conversion circuit according to claim 8, characterized in that, The sampling processing module (200) further includes: The output of the second oscillation module (240) is connected to the first input of the subtractor (230) and is used to input the ramp signal (Ramp) into the subtractor (230).

10. A power management chip, characterized in that, Includes the DC-DC conversion circuit as described in any one of claims 1-9.

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