Charge pump circuit and system on chip

Abstract

The invention provides a charge pump circuit and a system-on-chip. The output end of a charge pump is connected to one end of a load resistor, the other end of the load resistor is connected to one end of a first resistor, the other end of the first resistor is connected to one end of a second resistor, and the other end of the second resistor is connected to a first reference power supply or grounded; the first end of the voltage detection module is connected between the first resistor and the load resistor, and the output end of the voltage detection module is connected to the control end of the reference module; the first end of the reference module is connected between the first resistor and the second resistor, and the second end of the reference module is connected to the output end of the charge pump. The change speed of the output voltage of the charge pump is regulated and controlled by stages in combination with the first target threshold value, so that the output voltage of the charge pump can be quickly close to the target voltage, the starting time is shortened, the possibility of voltage overshoot can be reduced, and the purpose of preventing overshoot and quickly starting the charge pump is achieved.

Description

Technical Field

[0001] The present invention relates to the field of charge pumps, and in particular to a charge pump circuit and a system on chip. Background Art

[0002] Charge pump is also called switched capacitor DC-DC converter. When compared with inductor-based DC-DC switching power supply, it is also called inductive DC-DC power converter. Charge pump is mainly used for voltage regulation, which can provide read, write or erase power for memory (including EEPROM and Flash memory).

[0003] In practical applications, the output voltage (VNEG) of the charge pump needs to have a fast response energy to ensure the operating performance of the system. However, if the output voltage of the charge pump is established too quickly, the output voltage may overshoot, causing the system circuit to have a CMOS device withstand voltage problem (also known as the BV problem), so it is necessary to prevent the voltage process. How to balance the above two requirements has become a difficult problem that technicians in this field are concerned about. Summary of the invention

[0004] The object of the present invention is to provide a charge pump circuit and a system on chip to improve the above problems.

[0005] In order to achieve the above purpose, the technical solution adopted by the embodiment of the present invention is as follows:

[0006] In a first aspect, an embodiment of the present invention provides a charge pump circuit, the charge pump circuit comprising a charge pump, a load resistor, a first resistor, a second resistor, a voltage detection module and a reference module;

[0007] The output end of the charge pump is connected to one end of the load resistor, the other end of the load resistor is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor, and the other end of the second resistor is connected to a first reference power supply or ground;

[0008] The first end of the voltage detection module is connected between the first resistor and the load resistor, and the output end of the voltage detection module is connected to the control end of the reference module;

[0009] A first end of the reference module is connected between the first resistor and the second resistor, and a second end of the reference module is connected to an output end of the charge pump.

[0010] Optionally, the charge pump is used to adjust its output voltage according to a first change slope after receiving an enable signal, wherein the first change slope corresponds to an initial operating current of the reference module;

[0011] The voltage detection module is used for sending a trigger signal to the reference module when the output voltage of the charge pump reaches a first target threshold;

[0012] The reference module is used to adjust its operating current when receiving the trigger signal;

[0013] After the reference module adjusts its operating current, the charge pump is used to adjust its output voltage according to a second change slope, wherein the absolute value of the second change slope is smaller than the absolute value of the first change slope.

[0014] Optionally, the reference module includes a bias current adjustment unit, a first operational amplifier and a first capacitor;

[0015] The control end of the bias current adjustment unit serves as the control end of the reference module and is connected to the output end of the voltage detection module;

[0016] The output end of the bias current adjustment unit is connected to the positive power input end of the first operational amplifier, and the current flowing into the positive power input end of the first operational amplifier is the working current of the reference module;

[0017] The first input terminal of the first operational amplifier is used as the first terminal of the reference module and is connected between the first resistor and the second resistor; the second input terminal of the first operational amplifier is used to access the second reference voltage;

[0018] The output end of the first operational amplifier is connected to one electrode of the first capacitor, and the other electrode of the first capacitor serves as the second end of the reference module and is connected to the output end of the charge pump.

[0019] Optionally, the bias current adjustment unit includes: a first MOS transistor, a second MOS transistor, a third MOS transistor, a fourth MOS transistor and a bias current source;

[0020] The drain of the first MOS tube, the drain of the second MOS tube and the drain of the fourth MOS tube are connected to a driving power supply;

[0021] The source of the first MOS transistor is connected to the first end of the bias current source, and the second end of the bias current source is grounded;

[0022] The gate of the fourth MOS tube serves as the control end of the bias current adjustment unit and is connected to the output end of the voltage detection module, and the source of the fourth MOS tube is connected to the drain of the third MOS tube;

[0023] The gate of the third MOS tube and the gate of the second MOS tube are both connected to the gate of the first MOS tube;

[0024] A connection terminal is led out at the connection between the source of the third MOS tube and the source of the second MOS tube, serving as the output end of the bias current adjustment unit and connected to the positive power input end of the first operational amplifier.

[0025] Optionally, the reference module further includes a fifth MOS tube;

[0026] The gate of the fifth MOS transistor is connected to the output end of the first operational amplifier, the drain of the fifth MOS transistor is connected to the control end of the charge pump, and the source of the fifth MOS transistor is grounded;

[0027] The first operational amplifier is used to stop working when the output voltage of the charge pump reaches a second target threshold value, so that the fifth MOS transistor works in a non-saturated state;

[0028] When the charge pump detects that the fifth MOS tube is in a non-saturated state, the charge pump maintains a stable output voltage.

[0029] Optionally, the voltage detection module includes a second comparator;

[0030] The first input terminal of the second comparator serves as the first terminal of the voltage detection module and is connected between the first resistor and the load resistor;

[0031] The second input terminal of the second comparator is used to access a third reference voltage;

[0032] The output end of the second comparator serves as the output end of the voltage detection module and is connected to the control end of the reference module.

[0033] Optionally, when the charge pump outputs a negative voltage, the first input terminal of the second comparator is a non-inverting input terminal, the second input terminal of the second comparator is an inverting input terminal, and the other end of the second resistor is connected to a first reference power supply of a positive voltage;

[0034] Before the output voltage of the charge pump reaches a first target threshold, the first comparator outputs a high level signal;

[0035] When the output voltage of the charge pump reaches a first target threshold, the first comparator outputs a low level signal as a trigger signal.

[0036] Optionally, when the charge pump outputs a positive voltage, the first input terminal of the second comparator is an inverting input terminal, the second input terminal of the second comparator is a non-inverting input terminal, and the other end of the second resistor is grounded;

[0037] Before the output voltage of the charge pump reaches a first target threshold, the first comparator outputs a high level signal;

[0038] When the output voltage of the charge pump reaches a first target threshold, the first comparator outputs a low level signal as a trigger signal.

[0039] In a second aspect, an embodiment of the present invention provides a system on chip, which includes the above-mentioned charge pump circuit.

[0040] In a third aspect, an embodiment of the present invention provides an electronic device, comprising the above-mentioned system on chip.

[0041] Compared with the prior art, the embodiment of the present invention provides a charge pump circuit and a system on chip, wherein the charge pump circuit includes a charge pump, a load resistor, a first resistor, a second resistor, a voltage detection module and a reference module; the output end of the charge pump is connected to one end of the load resistor, the other end of the load resistor is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor, and the other end of the second resistor is connected to a first reference power supply or ground; the first end of the voltage detection module is connected between the first resistor and the load resistor, and the output end of the voltage detection module is connected to the control end of the reference module; the first end of the reference module is connected between the first resistor and the second resistor, and the second end of the reference module is connected to the output end of the charge pump. By adjusting the change speed of the output voltage of the charge pump in stages in combination with the first target threshold, the output voltage of the charge pump can be quickly approached to the target voltage, the startup time can be shortened, and the possibility of voltage overshoot can be reduced, thereby achieving the purpose of a charge pump that prevents overshoot and starts quickly.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 This is one of the structural schematic diagrams of the charge pump circuit provided by the embodiment of the present invention.

[0045] Figure 2 The second structural schematic diagram of the charge pump circuit provided in the embodiment of the present invention.

[0046] Figure 3 The third structural schematic diagram of the charge pump circuit provided in the embodiment of the present invention.

[0047] In the figure: 10 - charge pump; 20 - reference module; 21 - bias current adjustment unit; 30 - voltage detection module. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0049] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0051] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0052] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0053] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0055] Increasing the energy storage capacitor at the output of the charge pump can reduce the possibility of voltage overshoot, but it will increase the area of ​​the circuit and may cause the charge pump startup time to be extended. Reducing the bias current Ibias will reduce the charge pump startup speed, thereby reducing the possibility of voltage overshoot, but it will reduce the current output capacity of the charge pump, which may affect the performance of the system.

[0056] In order to achieve the purpose of anti-overshoot and fast-start charge pump, the embodiment of the present invention provides a charge pump circuit, which controls the change slope of the charge pump output voltage in stages, thereby ensuring the charge pump startup speed, ensuring the charge pump current output capacity, and reducing the possibility of voltage overshoot. Figure 1 , Figure 1 It is one of the structural diagrams of the charge pump circuit provided in the embodiment of the present invention. It should be noted that in the embodiment of the present invention, ① represents the first end of the corresponding device, ② represents the second end of the corresponding device, and ③ represents the third end of the corresponding device, which will not be described in detail hereinafter.

[0057] The charge pump circuit includes a charge pump 10 , a load resistor RD, a first resistor R1 , a second resistor R2 , a reference module 20 and a voltage detection module 30 .

[0058] The output end of the charge pump 10 is connected to one end of the load resistor RD, the other end of the load resistor RD is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to one end of the second resistor R2, and the other end of the second resistor R2 is connected to the first reference power supply Vref1 or ground.

[0059] A first terminal of the voltage detection module 30 is connected between the first resistor R1 and the load resistor RD, and an output terminal of the voltage detection module 30 is connected to a control terminal of the reference module 20 .

[0060] A first terminal of the reference module 20 is connected between the first resistor R1 and the second resistor R2 , and a second terminal of the reference module 20 is connected to an output terminal of the charge pump 10 .

[0061] It should be noted that the load resistor RD, the first resistor R1 and the second resistor R2 are connected in series between the output end of the charge pump 10 and the first reference power supply Vref1 (or ground), so there is a linkage relationship between the voltages of point A, point B and point C shown in the figure, and the voltage at point A is the output voltage VNEG of the charge pump 10. The voltage detection module 30 can detect the voltage at point B, which is equivalent to that it can detect the voltage at point A, and the reference module 20 can detect the voltage at point C, which is equivalent to that it can detect the voltage at point A.

[0062] Optionally, the charge pump 10 is configured to start working after receiving an enable signal, and adjust its output voltage according to a first change slope, wherein the first change slope corresponds to an initial working current of the reference module 20 .

[0063] The voltage detection module 30 is used to send a trigger signal (Slow shown in the figure) to the reference module 20 when the output voltage of the charge pump 10 reaches a first target threshold.

[0064] It should be understood that the voltage detection module 30 can determine whether the output voltage of the charge pump 10 reaches the first target threshold by monitoring the voltage at point B. It should be noted that the output voltage of the charge pump 10 can be a positive voltage, in which case the first target threshold is greater than 0; the output voltage of the charge pump 10 can also be a negative voltage, in which case the first target threshold is less than 0. The first target threshold can be, but is not limited to, 60% to 70% of the target voltage of the charge pump 10.

[0065] The reference module 20 is used to adjust its operating current when receiving a trigger signal.

[0066] Optionally, when receiving a trigger signal, the reference module 20 reduces its operating current, and the current reduction slows down the establishment time.

[0067] After the reference module 20 adjusts its operating current, the charge pump 10 is used to adjust its output voltage according to a second change slope, wherein the absolute value of the second change slope is smaller than the absolute value of the first change slope.

[0068] It should be noted that before the output voltage of the charge pump 10 reaches the first target threshold, the output voltage of the charge pump 10 is adjusted according to the first change slope, so that the output voltage of the charge pump 10 quickly approaches the target voltage and shortens the startup time. When the output voltage of the charge pump 10 reaches the first target threshold, it means that the output voltage of the charge pump 10 is close to the target voltage. In order to reduce the possibility of voltage overshoot, the change speed of the output voltage of the charge pump 10 is reduced by adjusting the working current of the reference module 20, so that the charge pump 10 is used to adjust its output voltage according to the second change slope, thereby achieving the purpose of a charge pump that prevents overshoot and starts quickly.

[0069] Based on the above, regarding the structure of the reference module, the embodiment of the present invention also provides an optional implementation method, please continue to refer to Figure 1 The reference module 20 includes a bias current adjustment unit 21 , a first operational amplifier U1 , and a first capacitor C1 .

[0070] The control end of the bias current adjustment unit 21 serves as the control end of the reference module 20 , is connected to the output end of the voltage detection module 30 , and is used to receive a trigger signal sent by the voltage detection module 30 .

[0071] The output end of the bias current adjustment unit 21 is connected to the positive power input end of the first operational amplifier U1, and the current flowing into the positive power input end of the first operational amplifier U1 is the operating current of the reference module 20 (Ig shown in the figure, Ig is the tail current source of the first operational amplifier U1).

[0072] The first input terminal of the first operational amplifier U1 serves as the first terminal of the reference module 20 and is connected between the first resistor R1 and the second resistor R2 ; the second input terminal of the first operational amplifier U1 is used to access the second reference voltage Vref2 .

[0073] The output terminal of the first operational amplifier U1 is connected to one electrode of the first capacitor C1, and the other electrode of the first capacitor C1 is used as the second end of the reference module 20 and connected to the output terminal of the charge pump 10. The first capacitor C1 can be used as an energy storage capacitor.

[0074] It should be understood that the operating current of the reference module 20 is different before the output voltage of the charge pump 10 reaches the first target threshold and after the output voltage of the charge pump 10 reaches the first target threshold. The absolute value of the change slope of the output voltage of the charge pump 10 is related to the operating current of the reference module 20 and the capacitance of the first capacitor C1. Optionally, the absolute value of the change slope = the operating current of the reference module 20 / the capacitance of the first capacitor C1.

[0075] Optionally, when the charge pump outputs a negative voltage, the first input terminal of the first operational amplifier U1 is a non-inverting input terminal, the second input terminal of the first operational amplifier U1 is an inverting input terminal, the other end of the second resistor R2 is connected to the first reference power supply Vref1 (a positive voltage), and the second reference voltage Vref2 is a reference ground (VSS). When the charge pump outputs a positive voltage, the first input terminal of the first operational amplifier U1 is a non-inverting input terminal, the second input terminal of the first operational amplifier U1 is an inverting input terminal, the other end of the second resistor R2 is grounded, and the second reference voltage Vref2 is a positive voltage.

[0076] Based on the above, regarding the structure of the bias current adjustment unit, the embodiment of the present invention also provides an optional implementation method, please refer to Figure 2 , Figure 2 The second structural schematic diagram of the charge pump circuit provided in the embodiment of the present invention.

[0077] The bias current adjustment unit 21 includes: a first MOS transistor M1, a second MOS transistor M2, a third MOS transistor M3, a fourth MOS transistor M4 and a bias current source Ibais.

[0078] The drain of the first MOS tube M1 , the drain of the second MOS tube M2 , and the drain of the fourth MOS tube M4 are connected to a driving power source.

[0079] A source of the first MOS transistor M1 is connected to a first end of a bias current source Ibais, and a second end of the bias current source Ibais is grounded.

[0080] It should be noted that the bias current source Ibais is used to draw the current flowing through the first MOS transistor M1 , and the current flowing through the first MOS transistor M1 is Ibais.

[0081] The gate of the fourth MOS transistor M4 serves as the control end of the bias current adjustment unit 21 and is connected to the output end of the voltage detection module 30 . The source of the fourth MOS transistor M4 is connected to the drain of the third MOS transistor M3 .

[0082] The gate of the third MOS transistor M3 and the gate of the second MOS transistor M2 are both connected to the gate of the first MOS transistor M1.

[0083] At the connection between the source of the third MOS tube M3 and the source of the second MOS tube M2, a connection terminal is led out as the output end of the bias current adjustment unit 21, which is connected to the positive power input terminal of the first operational amplifier U1.

[0084] It should be noted that before the output voltage of the charge pump 10 reaches the first target threshold, the voltage detection module 30 outputs a high level signal, and the fourth MOS tube M4 is in a conducting state. The current mirror composed of the first MOS tube M1 and the second MOS tube M2, and the current mirror composed of the first MOS tube M1 and the third MOS tube M3 are both working.

[0085] The current I2 flowing through the second MOS transistor M2 and the current I3 flowing through the third MOS transistor M3 are proportional to the current Ibais flowing through the first MOS transistor M1. In an optional implementation, the current I2 and the current I3 are both half of the current Ibais.

[0086] When the fourth MOS transistor M4 is in the on state, the operating current Ig is the sum of the current I2 and the current I3.

[0087] When the output voltage of the charge pump 10 reaches the first target threshold, the voltage detection module 30 outputs a low-level trigger signal, the fourth MOS tube M4 is switched to the off state, and the current I3 becomes 0, that is, the working current Ig is the current I2, and the working current Ig is reduced compared with the previous state.

[0088] Please continue to refer to Figure 1 and Figure 2 In an optional implementation, the reference module 20 further includes a fifth MOS transistor M5.

[0089] When the charge pump 10 outputs a negative voltage, the fifth MOS tube M5 is an NMOS tube. The gate of the fifth MOS tube M5 is connected to the output terminal of the first operational amplifier U1, the drain of the fifth MOS tube M5 is connected to the control terminal of the charge pump 10, and the source of the fifth MOS tube M5 is grounded.

[0090] When the charge pump 10 outputs a positive voltage, the fifth MOS tube M5 is a PMOS tube. The gate of the fifth MOS tube M5 is connected to the output terminal of the first operational amplifier U1, the source of the fifth MOS tube M5 is connected to the control terminal of the charge pump 10, and the drain of the fifth MOS tube M5 is grounded.

[0091] The first operational amplifier U1 is used to stop working when the output voltage of the charge pump 10 reaches the second target threshold value, so that the fifth MOS transistor M5 works in a non-saturated state.

[0092] The second target threshold may be a target voltage corresponding to the charge pump 10 , and the absolute value of the second target threshold is greater than the absolute value of the second target threshold.

[0093] Optionally, VNEG 目标 =[(Rd+R2) / R1]×Vref1, where VNEG 目标 is the target voltage, Rd represents the load resistance, R1 represents the first resistance, R2 represents the second resistance, and Vref1 represents the voltage of the first reference power supply.

[0094] When the charge pump 10 detects that the fifth MOS transistor M5 is in a non-saturated state, the charge pump 10 maintains a stable output voltage.

[0095] It should be understood that before the output voltage of the charge pump 10 reaches the second target threshold, the fifth MOS transistor M5 operates in a saturation state.

[0096] Please refer to Figure 2 and Figure 3 , Figure 3 The third structural diagram of the charge pump circuit provided by the embodiment of the present invention. In an optional implementation, the voltage detection module 30 includes a second comparator U2.

[0097] The first input terminal of the second comparator U2 serves as the first terminal of the voltage detection module 30 and is connected between the first resistor R1 and the load resistor RD.

[0098] The second input terminal of the second comparator U2 is used to access the third reference voltage Vref3.

[0099] The output terminal of the second comparator U2 serves as the output terminal of the voltage detection module 30 and is connected to the control terminal of the reference module 20 .

[0100] Optionally, when the charge pump 10 outputs a negative voltage, the first input terminal of the second comparator U2 is the non-inverting input terminal, the second input terminal of the second comparator U2 is the inverting input terminal, the other end of the second resistor R2 is connected to the first reference power supply Vref1 of the positive voltage, and the third reference voltage Vref3 is the reference ground.

[0101] Optionally, when the charge pump 10 outputs a positive voltage, the first input terminal of the second comparator U2 is an inverting input terminal, the second input terminal of the second comparator U2 is a non-inverting input terminal, the other end of the second resistor R2 is grounded, and the third reference voltage Vref3 is a positive voltage.

[0102] Before the output voltage of the charge pump 10 reaches the first target threshold, the first comparator outputs a high level signal. When the output voltage of the charge pump 10 reaches the first target threshold, the first comparator outputs a low level signal as a trigger signal.

[0103] An embodiment of the present invention further provides a system on chip, which includes the above-mentioned charge pump circuit.

[0104] The embodiment of the present invention further provides an electronic device, including the above-mentioned system on chip. The electronic device can be, but is not limited to, a mobile phone device, a computer device, a portable wearable device, and the like.

[0105] In summary, the embodiment of the present invention provides a charge pump circuit and a system on chip, the charge pump circuit includes a charge pump, a load resistor, a first resistor, a second resistor, a voltage detection module and a reference module; the output end of the charge pump is connected to one end of the load resistor, the other end of the load resistor is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor, and the other end of the second resistor is connected to a first reference power supply or ground; the first end of the voltage detection module is connected between the first resistor and the load resistor, and the output end of the voltage detection module is connected to the control end of the reference module; the first end of the reference module is connected between the first resistor and the second resistor, and the second end of the reference module is connected to the output end of the charge pump. Combined with the first target threshold, the change speed of the output voltage of the charge pump is regulated in stages, so that the output voltage of the charge pump can be quickly approached to the target voltage, the startup time can be shortened, and the possibility of voltage overshoot can be reduced, thereby achieving the purpose of a charge pump that prevents overshoot and starts quickly.

[0106] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0107] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A charge pump circuit, characterized in that: The charge pump circuit comprises a charge pump, a load resistor, a first resistor, a second resistor, a voltage detection module and a reference module; The output end of the charge pump is connected to one end of the load resistor, the other end of the load resistor is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor, and the other end of the second resistor is connected to a first reference power supply or ground; The first end of the voltage detection module is connected between the first resistor and the load resistor, and the output end of the voltage detection module is connected to the control end of the reference module; A first end of the reference module is connected between the first resistor and the second resistor, and a second end of the reference module is connected to an output end of the charge pump.

2. The charge pump circuit according to claim 1, wherein: The charge pump is used to adjust its output voltage according to a first change slope after receiving an enable signal, wherein the first change slope corresponds to an initial operating current of the reference module; The voltage detection module is used for sending a trigger signal to the reference module when the output voltage of the charge pump reaches a first target threshold; The reference module is used to adjust its operating current when receiving the trigger signal; After the reference module adjusts its operating current, the charge pump is used to adjust its output voltage according to a second change slope, wherein the absolute value of the second change slope is smaller than the absolute value of the first change slope.

3. The charge pump circuit according to claim 1, wherein: The reference module includes a bias current adjustment unit, a first operational amplifier and a first capacitor; The control end of the bias current adjustment unit serves as the control end of the reference module and is connected to the output end of the voltage detection module; The output end of the bias current adjustment unit is connected to the positive power input end of the first operational amplifier, and the current flowing into the positive power input end of the first operational amplifier is the working current of the reference module; The first input terminal of the first operational amplifier is used as the first terminal of the reference module and is connected between the first resistor and the second resistor; the second input terminal of the first operational amplifier is used to access the second reference voltage; The output end of the first operational amplifier is connected to one electrode of the first capacitor, and the other electrode of the first capacitor serves as the second end of the reference module and is connected to the output end of the charge pump.

4. The charge pump circuit according to claim 3, characterized in that: When the charge pump outputs a negative voltage, the first input terminal of the first operational amplifier is a non-inverting input terminal, the second input terminal of the first operational amplifier is an inverting input terminal, the other end of the second resistor is connected to a first reference power supply with a positive voltage, and the second reference voltage is a reference ground; When the charge pump outputs a positive voltage, the first input terminal of the first operational amplifier is a non-inverting input terminal, the second input terminal of the first operational amplifier is an inverting input terminal, the other end of the second resistor is grounded, and the second reference voltage is a positive voltage.

5. The charge pump circuit according to claim 3, wherein: The bias current adjustment unit includes: a first MOS tube, a second MOS tube, a third MOS tube, a fourth MOS tube and a bias current source; The drain of the first MOS tube, the drain of the second MOS tube and the drain of the fourth MOS tube are connected to a driving power supply; The source of the first MOS transistor is connected to the first end of the bias current source, and the second end of the bias current source is grounded; The gate of the fourth MOS tube serves as the control end of the bias current adjustment unit and is connected to the output end of the voltage detection module, and the source of the fourth MOS tube is connected to the drain of the third MOS tube; The gate of the third MOS tube and the gate of the second MOS tube are both connected to the gate of the first MOS tube; A connection terminal is led out from the connection between the source of the third MOS tube and the source of the second MOS tube, serving as the output end of the bias current adjustment unit and connected to the positive power input end of the first operational amplifier.

6. The charge pump circuit according to claim 3, characterized in that: The reference module further includes a fifth MOS tube, and when the charge pump outputs a negative voltage, the fifth MOS tube is an NMOS tube; The gate of the fifth MOS transistor is connected to the output end of the first operational amplifier, the drain of the fifth MOS transistor is connected to the control end of the charge pump, and the source of the fifth MOS transistor is grounded; The first operational amplifier is used to stop working when the output voltage of the charge pump reaches a second target threshold value, so that the fifth MOS transistor works in a non-saturated state; When the charge pump detects that the fifth MOS tube is in a non-saturated state, the charge pump maintains a stable output voltage.

7. The charge pump circuit according to claim 1, wherein: The voltage detection module includes a second comparator; The first input terminal of the second comparator serves as the first terminal of the voltage detection module and is connected between the first resistor and the load resistor; The second input terminal of the second comparator is used to access a third reference voltage; The output end of the second comparator serves as the output end of the voltage detection module and is connected to the control end of the reference module.

8. The charge pump circuit according to claim 7, wherein: When the charge pump outputs a negative voltage, the first input terminal of the second comparator is a non-inverting input terminal, the second input terminal of the second comparator is an inverting input terminal, and the other end of the second resistor is connected to a first reference power supply with a positive voltage; Before the output voltage of the charge pump reaches a first target threshold, the first comparator outputs a high level signal; When the output voltage of the charge pump reaches a first target threshold, the first comparator outputs a low level signal as a trigger signal.

9. The charge pump circuit according to claim 8, characterized in that When the charge pump outputs a positive voltage, the first input terminal of the second comparator is an inverting input terminal, the second input terminal of the second comparator is a non-inverting input terminal, and the other end of the second resistor is grounded; Before the output voltage of the charge pump reaches a first target threshold, the first comparator outputs a high level signal; When the output voltage of the charge pump reaches a first target threshold, the first comparator outputs a low level signal as a trigger signal.

10. A system on chip, characterized in that: The system on chip comprises the charge pump circuit according to any one of claims 1 to 9.

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