Driving circuit for driving input power tube in charge pump, high-voltage charge pump and electronic equipment

Abstract

The invention provides a driving circuit for driving an input power tube in a charge pump, the input power tube of the charge pump is an NMOS tube, conduction loss is reduced, a source electrode of the input power tube receives input voltage, and a drain electrode of the input power tube is coupled to a first end of a flying capacitor; a grid electrode of a high-end source-following NMOS tube of the driving circuit receives adjustable reference voltage, a drain electrode of the high-end source-following NMOS tube is coupled to an output end of the charge pump, a source electrode of the high-end source-following NMOS tube is coupled to a drain electrode of a low-end source-following NMOS tube, a source electrode of the low-end source-following NMOS tube is coupled to a drain electrode of a pull-down NMOS tube, a grid electrode of the low-end source-following NMOS tube is coupled to a grid electrode of the pull-down NMOS tube, and the grid electrode of the pull-down NMOS tube is coupled to the output end of the charge pump. The grid electrode of the pull-down NMOS tube further receives an input power tube control signal through the driver, the source electrode of the pull-down NMOS tube is coupled to the first end of the flying capacitor, and the drain electrode of the pull-down NMOS tube is further coupled to the grid electrode of the input power tube. And the driving circuit directly receives the input voltage, so that the area of the charge pump is reduced.

Description

Technical Field

[0001] The present invention relates to the field of power electronics, and in particular to a driving circuit for driving an input power tube in a charge pump, a high-voltage charge pump and an electronic device. Background Art

[0002] A charge pump is a switched capacitor voltage converter that uses capacitors as energy storage elements. The internal MOSFET switch tube is periodically turned on and off under the control of a clock signal, so that the output capacitor is constantly switching between charging and discharging states and outputs a fixed output voltage value.

[0003] The output voltage of the high-voltage charge pump is higher than the input voltage value. However, the current high-voltage charge pump input power tube cannot directly receive the input voltage. An additional voltage modulation device is required to receive the input voltage and generate the stable reference voltage required by the charge pump input. The high-voltage charge pump then uses the stable reference voltage to output the output voltage. Due to the large size of the voltage modulation device, it is generally placed outside the charge pump chip, making the current high-voltage charge pump difficult to use in smaller applications.

[0004] Therefore, how to ensure that the output voltage of the high-voltage charge pump is adjustable while reducing the area of ​​the charge pump has become a technical problem that urgently needs to be solved in the industry. Summary of the invention

[0005] The present invention provides a driving circuit, a high-voltage charge pump and an electronic device for driving an input power tube in a charge pump, which solves the technical problem of how to ensure that the output voltage of the high-voltage charge pump is adjustable while reducing the area of ​​the charge pump.

[0006] According to a first aspect of the present invention, an embodiment of the present invention provides a driving circuit for driving an input power tube in a charge pump, wherein the input power tube is an NMOS tube, a source of the input power tube receives an input voltage, and a drain of the input power tube is coupled to a first end of a flying capacitor;

[0007] The driving circuit comprises: a high-end source follower NMOS tube, a low-end source follower NMOS tube and a pull-down NMOS tube;

[0008] The gate of the high-end source follower NMOS tube receives an adjustable reference voltage, the drain of the high-end source follower NMOS tube is coupled to the output end of the charge pump, the source of the high-end source follower NMOS tube is coupled to the drain of the low-end source follower NMOS tube, the source of the low-end source follower NMOS tube is coupled to the drain of the pull-down NMOS tube, the gate of the low-end source follower NMOS tube is coupled to the gate of the pull-down NMOS tube, the gate of the pull-down NMOS tube also receives an input power tube control signal through a driver, the source of the pull-down NMOS tube is coupled to the first end of the flying capacitor, and the drain of the pull-down NMOS tube is also coupled to the gate of the input power tube.

[0009] Optionally, a high-level voltage value of the input power tube control signal output by the driver is equal to a voltage value of the floating voltage, and a low-level voltage value of the input power tube control signal output by the driver is equal to a voltage value of the flying capacitor.

[0010] Optionally, the driving circuit further includes a floating voltage generating module;

[0011] The first end of the floating voltage generating module is coupled to the output end of the charge pump, the second end thereof is coupled to the first end of the flying capacitor, the output end thereof is coupled to the power supply end of the driver, and the ground end of the driver is coupled to the first end of the flying capacitor;

[0012] The floating voltage generating module is used to output a floating voltage to the power supply terminal of the driver, the voltage value of the floating voltage is higher than the voltage value of the flying capacitor, and the difference between the voltage value of the floating voltage and the voltage value of the flying capacitor is a set value.

[0013] Optionally, the floating voltage generating module includes a Zener diode and a first NMOS tube;

[0014] The anode of the Zener diode is coupled to the first end of the flying capacitor, and the cathode of the Zener diode is coupled to the output end of the charge pump and the gate of the first NMOS tube respectively;

[0015] The drain of the first NMOS tube is coupled to the output end of the charge pump, and the source of the first NMOS tube is coupled to the power supply end of the driver.

[0016] Optionally, a short circuit protection module is further included, wherein the short circuit protection module includes a first resistor and a first diode;

[0017] The first end of the first resistor receives the adjustable reference voltage, and the second end thereof is respectively coupled to the gate of the high-end source follower NMOS tube and the cathode of the first diode, and the anode of the first diode is coupled to the source of the high-end source follower NMOS tube.

[0018] Optionally, a current limiting control module is further included, wherein a first end of the current limiting control module is coupled to the gate of the input power tube, and a second end of the current limiting control module is coupled to the first end of the flying capacitor.

[0019] Optionally, the current limiting control module includes N current limiting branches connected in parallel, a current limiting NMOS tube and a switch control unit;

[0020] The first end of each current limiting branch is coupled to the source of the low-end source follower NMOS tube, the second end of each current limiting branch is respectively coupled to the drain of the pull-down NMOS tube and the drain of the current limiting NMOS tube, the source of the current limiting NMOS tube is coupled to the first end of the flying capacitor, the gate of the current limiting NMOS tube is coupled to the drain of the current limiting NMOS tube, and the switch control unit is respectively coupled to the control end of each current limiting branch to control the on and off of each current limiting branch.

[0021] Optionally, each current limiting branch includes a current limiting switch and a current limiting resistor electrically connected in sequence, and the switch control unit is respectively coupled to the control end of each current limiting switch.

[0022] According to a second aspect of the present invention, an embodiment of the present invention provides a high-voltage charge pump, comprising: an input power tube control module and an input power tube of the driving circuit as described in any one of the first aspects of the present invention.

[0023] Optionally, the high-voltage charge pump further includes: a transmission NMOS tube, an output PMOS tube, a grounding NMOS tube, a flying capacitor, an output capacitor and a general control module;

[0024] The drain of the input power tube receives the input voltage, and the source thereof is respectively coupled to the first end of the flying capacitor and the drain of the grounded NMOS tube; the gate of the input power tube is coupled to the output end of the input gate control module, and the input end of the input power tube control module is coupled to the first end of the general control module; the gate of the grounded NMOS tube is coupled to the second end of the general control module through the grounded gate control module, and the source thereof is grounded.

[0025] The source of the output PMOS tube is coupled to the first end of the output capacitor, the drain of the output PMOS tube is coupled to the drain of the transmission NMOS tube and the second end of the flying capacitor respectively, and the gate of the output PMOS tube is coupled to the third end of the general control module through the output gate control module;

[0026] The source of the transmission NMOS tube receives the input voltage, and the source of the transmission NMOS tube is also coupled to the second end of the output capacitor, the gate of the transmission NMOS tube is coupled to the fourth end of the general control module through the transmission gate control module, and the first end of the output capacitor is used to output the output voltage;

[0027] The overall control module is used to control the on and off of the input power tube, the transmission NMOS tube, the output PMOS tube and the grounding NMOS tube, so that the voltage value of the output voltage is the target voltage value.

[0028] Optionally, the high voltage charge pump further includes:

[0029] A flying voltage detection module, a first end of which is coupled to the first end of the flying capacitor, and a second end of which is coupled to the fifth end of the general control module, and the flying voltage detection module is used to detect the voltage value of the flying capacitor;

[0030] an output voltage detection module, a first end of which receives an input voltage, a second end of which is coupled to the first end of the output capacitor, and a third end of which is coupled to the sixth end of the main control module, and the output voltage detection module is used to detect a voltage value of the output voltage;

[0031] The overall control module is also used for:

[0032] Based on the voltage value of the output voltage and / or the voltage value of the flying capacitor, it is determined whether the charge pump is in a normal working state, wherein:

[0033] Only when the voltage value of the flying capacitor is maintained within the first set voltage range and the voltage value of the output voltage is higher than the second set voltage value, it is determined that the charge pump is in a normal working state.

[0034] According to a third aspect of the present invention, an embodiment of the present invention provides an electronic device, comprising: a high-voltage charge pump as described in any one of the second aspect of the present invention.

[0035] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0036] In the driving circuit for driving the input power tube in the charge pump of the technical solution of the present invention, the input power tube of the charge pump is an NMOS tube, which reduces the conduction loss, and the source of the input power tube receives the input voltage, and the drain of the input power tube is coupled to the first end of the flying capacitor; the gate of the high-end source-following NMOS tube of the driving circuit receives the adjustable reference voltage, the drain of the high-end source-following NMOS tube is coupled to the output end of the charge pump, and the source of the high-end source-following NMOS tube is coupled to the drain of the pull-down NMOS tube, the gate of the low-end source-following NMOS tube is coupled to the gate of the pull-down NMOS tube, the gate of the pull-down NMOS tube also receives the input power tube control signal through the driver, the source of the pull-down NMOS tube is coupled to the first end of the flying capacitor, and the drain of the pull-down NMOS tube is also coupled to the gate of the input power tube. The present invention changes the output voltage of the charge pump by adjusting the voltage value of the adjustable reference voltage, and the driving circuit of the present invention directly receives the input voltage, thereby reducing the area of ​​the charge pump.

[0037] In the high-voltage charge pump and electronic device of the technical solution of the present invention, by applying the driving circuit of the technical solution for driving the input power tube in the charge pump, the output voltage of the high-voltage charge pump can be changed by adjusting the voltage value of the adjustable reference voltage, and the driving circuit of the present invention directly receives the input voltage, so that the area of ​​the high-voltage charge pump of the present invention is smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 It is a schematic diagram of the structure of a high-voltage charge pump in the prior art;

[0040] Figure 2 is a schematic structural diagram of a driving circuit for driving an input power tube in a charge pump in one embodiment of the present invention;

[0041] Figure 3 is a schematic structural diagram of a driving circuit in another embodiment of the present invention;

[0042] Figure 4 is a structural schematic diagram of a floating voltage generating module in one embodiment of the present invention;

[0043] Figure 5 is a schematic structural diagram of a driving circuit in another embodiment of the present invention;

[0044] Figure 6is a structural schematic diagram of a current limiting control module in one embodiment of the present invention;

[0045] Figure 7 A schematic diagram of the structure of a high voltage charge pump in an embodiment of the present invention;

[0046] Description of reference numerals:

[0047] CNH-input power tube;

[0048] CNH_REFSFH-high-end source follower NMOS tube;

[0049] CNH_REFSFL-low-side source follower NMOS tube;

[0050] CNH_REFPD-pull-down NMOS tube;

[0051] VCNHG-gate control signal;

[0052] 21- floating voltage generating module;

[0053] 201-Driver;

[0054] Z1-Zener diode;

[0055] M1-first NMOS tube;

[0056] 22- short circuit protection module;

[0057] R1-first resistor;

[0058] D1-first diode;

[0059] 23-current limiting control module;

[0060] CNHS-current limiting NMOS tube;

[0061] 231- switch control unit;

[0062] CPL-transmission NMOS tube;

[0063] CPH-output PMOS tube;

[0064] CNL-grounded NMOS tube;

[0065] C_FLY-flying capacitor;

[0066] CL-output capacitance;

[0067] 30- general control module;

[0068] 31- input gate control module;

[0069] 32- ground grid control module;

[0070] 33- output gate control module;

[0071] 34-transmission grid control module;

[0072] 35-flying voltage detection module;

[0073] 36- Output voltage detection module. DETAILED DESCRIPTION

[0074] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0075] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0076] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0077] As described in the background art, how to ensure that the output voltage of a high-voltage charge pump is adjustable while reducing the area of ​​the charge pump has become a technical problem that needs to be solved urgently in the industry.

[0078] Please refer to Figure 1 , Figure 1 A high voltage charge pump in the prior art is shown, comprising:

[0079] An input PMOS transistor Q1, a transmission NMOS transistor Q2, an output PMOS transistor Q3, a grounding NMOS transistor Q4, a flying capacitor C_FLY, an output capacitor CL and a general control module 10;

[0080] The source of the input PMOS transistor Q1 receives a stable reference voltage VREF_BUF, and the drain thereof is respectively coupled to the first end of the flying capacitor C_FLY and the drain of the grounded NMOS transistor Q4, and the gate of the input PMOS transistor Q1 is coupled to the first end of the general control module 10 through the input gate control module 11;

[0081] The gate of the grounded NMOS transistor Q4 is coupled to the second end of the main control module 10 through the grounded gate control module 12, and its source is grounded.

[0082] The source of the output PMOS tube Q3 is coupled to the first end of the output capacitor CL, and the drain thereof is respectively coupled to the drain of the transmission NMOS tube Q2 and the second end of the flying capacitor C_FLY. The gate of the output PMOS tube Q3 is coupled to the third end of the general control module 10 through the output gate control module 13.

[0083] The source of the transmission NMOS transistor Q2 receives the input voltage VIN, and the source of the transmission NMOS transistor Q2 is also coupled to the second end of the output capacitor CL, the gate of the transmission NMOS transistor Q2 is coupled to the fourth end of the general control module 10 through the transmission gate control module, and the first end of the output capacitor CL is used to output the output voltage VCP;

[0084] The overall control module 10 is used to control the on / off of the input PMOS transistor Q1 , the transmission NMOS transistor Q2 , the output PMOS transistor Q3 , and the grounding NMOS transistor Q4 , so that the voltage value of the output voltage VCP is a set voltage value.

[0085] Since the input power tube (input PMOS tube Q1) of the high-voltage charge pump in the prior art often adopts a PMOS tube, the conduction loss of the power tube is also relatively large.

[0086] Moreover, the stable reference voltage VREF_BUF is composed of Figure 1 The voltage modulation device 15 in the example includes a comparator 151, a first power transistor MLDO and a decoupling capacitor DECAP_C1;

[0087] The first end of the first power transistor MLDO receives the input voltage VIN, and the second end thereof is respectively coupled to the first end of the decoupling capacitor DECAP_C1 and the non-inverting input end of the comparator 151, the second end of the decoupling capacitor DECAP_C1 is grounded, the inverting input end of the comparator 151 receives the first reference voltage VREF1, and the output end thereof is coupled to the control end of the first power transistor MLDO, and the second end of the first power transistor MLDO is also used to output the stable reference voltage VREF_BUF;

[0088] Wherein, the first power tube MLDO is a PMOS tube.

[0089] In practical applications, the decoupling capacitor DECAP_C1 needs to have a larger capacitance and a larger area. Therefore, in some application scenarios, it is not possible to add an additional decoupling capacitor DECAP_C1 to the circuit, and the area of ​​the first power transistor MLDO is also larger, so that the area required for the voltage modulation device 15 as a whole is larger.

[0090] It can be seen that the high-voltage charge pump in the prior art has the problems of large area and high conduction loss.

[0091] In view of this, the present invention provides a driving circuit for driving an input power tube in a charge pump, wherein the input power tube of the charge pump is an NMOS tube, which reduces conduction loss, and the source of the input power tube receives an input voltage, and the drain of the input power tube is coupled to the first end of a flying capacitor; the gate of a high-end source-following NMOS tube of the driving circuit receives an adjustable reference voltage, the drain of the high-end source-following NMOS tube is coupled to the output end of the charge pump, and the source of the high-end source-following NMOS tube is coupled to the drain of a pull-down NMOS tube, the gate of the low-end source-following NMOS tube is coupled to the gate of the pull-down NMOS tube, the gate of the pull-down NMOS tube also receives an input power tube control signal through a driver, the source of the pull-down NMOS tube is coupled to the first end of the flying capacitor, and the drain of the pull-down NMOS tube is also coupled to the gate of the input power tube. The present invention changes the output voltage of the charge pump by adjusting the voltage value of the adjustable reference voltage, and the driving circuit of the present invention directly receives the input voltage, thereby reducing the area of ​​the charge pump.

[0092] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0093] Please refer to Figure 2 The embodiment of the present invention provides a driving circuit for driving an input power tube in a charge pump, wherein the input power tube CNH is an NMOS tube, the source of the input power tube CNH receives an input voltage VIN, and the drain is coupled to the first end CNFLY ( Figure 2 Flying capacitor is not shown);

[0094] The driving circuit includes: a high-end source follower NMOS tube CNH_REFSFH, a low-end source follower NMOS tube CNH_REFSFL and a pull-down NMOS tube CNH_REFPD;

[0095] The gate of the high-end source follower NMOS tube CNH_REFSFH receives the adjustable reference voltage VREF, the drain of which is coupled to the output terminal VCP of the charge pump, and the source of which is coupled to the drain of the low-end source follower NMOS tube CNH_REFSFL. The source of the low-end source follower NMOS tube CNH_REFSFL is coupled to the drain of the pull-down NMOS tube CNH_REFPD, the gate of the low-end source follower NMOS tube CNH_REFSFL is coupled to the gate of the pull-down NMOS tube CNH_REFPD, the gate of the pull-down NMOS tube CNH_REFPD also receives the input power tube control signal CONTROL1 through the driver 201, the source of the pull-down NMOS tube CNH_REFPD is coupled to the first terminal CNFLY of the flying capacitor, and the drain of the pull-down NMOS tube CNH_REFPD is also coupled to the gate of the input power tube CNH.

[0096] exist Figure 2 In the example, a node between the source of the low-end source follower NMOS tube CNH_REFSFL and the drain of the pull-down NMOS tube CNH_REFPD is used to output a gate control signal VCNHG to the gate of the input power tube CNH.

[0097] It can be seen that the present invention not only uses NMOS tubes as the input power tubes CNH of the charge pump to reduce conduction loss, but also changes the output voltage VCP of the charge pump by adjusting the voltage value of the adjustable reference voltage VREF. In addition, the driving circuit of the present invention directly receives the input voltage VIN, which reduces the area of ​​the charge pump.

[0098] In a preferred embodiment, the high level voltage value of the input power tube CNH control signal output by the driver 201 is equal to the voltage value of the floating voltage, and the low level voltage value of the input power tube CNH control signal output by the driver 201 is equal to the voltage value of the flying capacitor.

[0099] Therefore, the driver 201 of the present invention can ensure the stability of the on-off control of the input power tube CNH.

[0100] In this case, please refer to Figure 3 , the driving circuit also includes a floating voltage generating module 21;

[0101] The first end of the floating voltage generating module 21 is coupled to the output end VCP of the charge pump, the second end thereof is coupled to the first end CNFLY of the flying capacitor, the output end thereof is coupled to the power supply end of the driver 201, and the ground end of the driver 201 is coupled to the first end CNFLY of the flying capacitor;

[0102] The floating voltage generating module 21 is used to output a floating voltage VCNFLT to the power supply terminal of the driver 201 . The voltage value of the floating voltage VCNFLT is higher than the voltage value of the flying capacitor, and the difference between the voltage value of the floating voltage VCNFLT and the voltage value of the flying capacitor is a set value.

[0103] In a specific implementation, please refer to Figure 4 , the floating voltage generating module 21 includes a Zener diode Z1 and a first NMOS tube M1;

[0104] The anode of the Zener diode Z1 is coupled to the first terminal CNFLY of the flying capacitor, and the cathode of the Zener diode Z1 is coupled to the output terminal VCP of the charge pump and the gate of the first NMOS transistor M1 respectively;

[0105] The drain of the first NMOS transistor M1 is coupled to the output terminal VCP of the charge pump, and the source of the first NMOS transistor M1 is coupled to the power supply terminal of the driver 201 .

[0106] It should be understood that the present invention does not limit the specific circuit structure of the floating voltage generating module 21, and any circuit that can realize the generation of the floating voltage VCNFLT is within the protection scope of the present invention.

[0107] In order to prevent the flying capacitor in the charge pump from being short-circuited, thereby causing damage to the driving circuit, in one implementation, please refer to Figure 5 , the driving circuit further includes a short circuit protection module 22, and the short circuit protection module 22 includes a first resistor R1 and a first diode D1;

[0108] The first end of the first resistor R1 receives the adjustable reference voltage VREF, and the second end thereof is respectively coupled to the gate of the high-end source follower NMOS transistor CNH_REFSFH and the cathode of the first diode D1. The anode of the first diode D1 is coupled to the source of the high-end source follower NMOS transistor CNH_REFSFH.

[0109] Of course, in another protection mode, you can also choose to limit the current value flowing through the input power tube CNH. For details, please refer to Figure 5 The driving circuit also includes a current limiting control module 23, a first end of the current limiting control module 23 is coupled to the gate of the input power tube CNH, and a second end of the current limiting control module 23 is coupled to the first end CNFLY of the flying capacitor.

[0110] For a specific implementation, please refer to Figure 6 , the current limiting control module 23 includes N current limiting branches connected in parallel, a current limiting NMOS tube CNHS and a switch control unit 231;

[0111] The first end of each current limiting branch is coupled to the source of the low-end source follower NMOS tube CNH_REFSFL, the second end of each current limiting branch is respectively coupled to the drain of the pull-down NMOS tube CNH_REFPD and the drain of the current limiting NMOS tube CNHS, the source of the current limiting NMOS tube CNHS is coupled to the first end CNFLY of the flying capacitor, the gate of the current limiting NMOS tube CNHS is coupled to the drain of the current limiting NMOS tube CNHS, and the switch control unit 231 is respectively coupled to the control end of each current limiting branch to control the on and off of each current limiting branch.

[0112] exist Figure 6 In the example, each current limiting branch includes a current limiting switch (S1-SN) and a current limiting resistor (RL1-RLN) electrically connected in sequence, and the switch control unit 231 is respectively coupled to the control end of each current limiting switch.

[0113] Of course, the present invention does not limit the specific implementation of the current limiting module, and any circuit that can limit the current flowing through the input power tube CNH is within the protection scope of the present invention.

[0114] In summary, in the driving circuit of the charge pump of the present invention, by setting the input power tube CNH as an NMOS tube, the conduction loss is reduced, and the source of the input power tube CNH receives the input voltage VIN, and the drain thereof is coupled to the first end CNFLY of the flying capacitor; the gate of the high-end source follower NMOS tube CNH_REFSFH of the driving circuit receives the adjustable reference voltage VREF, the drain thereof is coupled to the output end of the charge pump, and the source thereof is coupled to the drain of the low-end source follower NMOS tube CNH_REFSFL, the source of the low-end source follower NMOS tube CNH_REFSFL is coupled to the drain of the pull-down NMOS tube CNH_REFPD, and the low-end source follower The gate of the NMOS tube CNH_REFSFL is coupled to the gate of the pull-down NMOS tube CNH_REFPD, and the gate of the pull-down NMOS tube CNH_REFPD also receives the input power tube CNH control signal through the driver 201. The source of the pull-down NMOS tube CNH_REFPD is coupled to the first end CNFLY of the flying capacitor, and the drain of the pull-down NMOS tube CNH_REFPD is also coupled to the gate of the input power tube CNH. The present invention changes the output voltage VCP of the charge pump by adjusting the voltage value of the adjustable reference voltage VREF, and the driving circuit of the present invention directly receives the input voltage VIN, thereby reducing the area of ​​the charge pump.

[0115] In addition, the present invention also provides a high voltage charge pump, please refer to Figure 7 , including: an input power tube control module of the driving circuit as any of the above items and an input power tube CNH.

[0116] In one implementation, please refer to Figure 7 , the high-voltage charge pump further includes: a transmission NMOS tube CPL, an output PMOS tube CPH, a grounding NMOS tube CNL, a flying capacitor C_FLY, an output capacitor CL and a general control module 30;

[0117] The drain of the input power tube CNH receives the input voltage VIN, and the source thereof is respectively coupled to the first end CNFLY of the flying capacitor C_FLY and the drain of the grounded NMOS tube CNL. The gate of the input power tube CNH is coupled to the output end of the input gate control module 31, and the input end of the input power tube control module 31 is coupled to the first end of the main control module 30; the gate of the grounded NMOS tube CNL is coupled to the second end of the main control module 30 through the grounded gate control module 32, and the source thereof is grounded.

[0118] The source of the output PMOS tube CPH is coupled to the first end of the output capacitor CL, and the drain thereof is respectively coupled to the drain of the transmission NMOS tube CPL and the second end CPFLY of the flying capacitor C_FLY, and the gate of the output PMOS tube CPH is coupled to the third end of the general control module 30 through the output gate control module 33;

[0119] The source of the transmission NMOS transistor CPL receives the input voltage VIN, and the source of the transmission NMOS transistor CPL is also coupled to the second end of the output capacitor CL, the gate of the transmission NMOS transistor CPL is coupled to the fourth end of the general control module 30 through the transmission gate control module 34, and the first end of the output capacitor CL is used to output the output voltage VCP;

[0120] The overall control module 30 is used to control the on / off of the input power transistor CNH, the transmission NMOS transistor CPL, the output PMOS transistor CPH and the grounding NMOS transistor CNL, so that the voltage value of the output voltage VCP is the target voltage value.

[0121] It can be seen that the present invention applies the technical solution for driving the driving circuit of the input power tube CNH in the charge pump, so that the present invention can change the output voltage VCP of the high-voltage charge pump by adjusting the voltage value of the adjustable reference voltage VREF, and the driving circuit of the present invention directly receives the input voltage VIN, so that the area of ​​the high-voltage charge pump of the present invention is smaller.

[0122] In actual work, one implementation method is to refer to Figure 7 , the high voltage charge pump further comprises:

[0123] A flying voltage detection module 35, a first end of which is coupled to the first end CNFLY of the flying capacitor C_FLY, and a second end of which is coupled to the fifth end of the main control module 30, and the flying voltage detection module 35 is used to detect the voltage value of the flying capacitor C_FLY;

[0124] An output voltage detection module 36, a first terminal of which receives an input voltage VIN, a second terminal of which is coupled to the first terminal of the output capacitor CL, and a third terminal of which is coupled to the sixth terminal of the main control module 30, and the output voltage detection module 36 is used to detect the voltage value of the output voltage VCP;

[0125] The overall control module 30 is also used for:

[0126] Based on the voltage value of the output voltage VCP and / or the voltage value of the flying capacitor C_FLY, it is determined whether the charge pump is in a normal working state, wherein:

[0127] Only when the voltage value of the flying capacitor C_FLY is maintained within the first set voltage range and the voltage value of the output voltage VCP is higher than the second set voltage value, it is determined that the charge pump is in a normal working state.

[0128] In addition, an embodiment of the present invention further provides an electronic device, including any of the above-mentioned high-voltage charge pumps. As an example, the electronic device can be a power device, of course, the present invention is not limited to this, and can also be other devices that require a charge pump type power supply with a high-voltage adjustable voltage continuous switch.

[0129] In summary, the embodiment of the present invention reduces the conduction loss by setting the input power tube of the charge pump to be an NMOS tube, and the source of the input power tube receives the input voltage, and the drain of the input power tube is coupled to the first end of the flying capacitor; the gate of the high-end source-follower NMOS tube of the driving circuit receives the adjustable reference voltage, the drain of the high-end source-follower NMOS tube is coupled to the output end of the charge pump, and the source of the high-end source-follower NMOS tube is coupled to the drain of the pull-down NMOS tube, the gate of the low-end source-follower NMOS tube is coupled to the gate of the pull-down NMOS tube, the gate of the pull-down NMOS tube also receives the input power tube control signal through the driver, the source of the pull-down NMOS tube is coupled to the first end of the flying capacitor, and the drain of the pull-down NMOS tube is also coupled to the gate of the input power tube. The present invention changes the output voltage of the charge pump by adjusting the voltage value of the adjustable reference voltage, and the driving circuit of the present invention directly receives the input voltage, thereby reducing the area of ​​the charge pump.

[0130] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A driving circuit for driving an input power tube in a charge pump, characterized in that: The input power tube is an NMOS tube, the source of the input power tube receives the input voltage, and the drain of the input power tube is coupled to the first end of the flying capacitor; The driving circuit comprises: a high-end source follower NMOS tube, a low-end source follower NMOS tube and a pull-down NMOS tube; The gate of the high-end source follower NMOS tube receives an adjustable reference voltage, the drain of the high-end source follower NMOS tube is coupled to the output end of the charge pump, the source of the high-end source follower NMOS tube is coupled to the drain of the low-end source follower NMOS tube, the source of the low-end source follower NMOS tube is coupled to the drain of the pull-down NMOS tube, the gate of the low-end source follower NMOS tube is coupled to the gate of the pull-down NMOS tube, the gate of the pull-down NMOS tube also receives an input power tube control signal through a driver, the source of the pull-down NMOS tube is coupled to the first end of the flying capacitor, and the drain of the pull-down NMOS tube is also coupled to the gate of the input power tube.

2. The driving circuit according to claim 1, characterized in that: The high level voltage value of the input power tube control signal output by the driver is equal to the voltage value of the floating voltage, and the low level voltage value of the input power tube control signal output by the driver is equal to the voltage value of the flying capacitor.

3. The driving circuit according to claim 2, characterized in that: The driving circuit also includes a floating voltage generating module; The first end of the floating voltage generating module is coupled to the output end of the charge pump, the second end thereof is coupled to the first end of the flying capacitor, the output end thereof is coupled to the power supply end of the driver, and the ground end of the driver is coupled to the first end of the flying capacitor; The floating voltage generating module is used to output a floating voltage to the power supply terminal of the driver, the voltage value of the floating voltage is higher than the voltage value of the flying capacitor, and the difference between the voltage value of the floating voltage and the voltage value of the flying capacitor is a set value.

4. The driving circuit according to claim 3, characterized in that: The floating voltage generating module includes a Zener diode and a first NMOS tube; The anode of the Zener diode is coupled to the first end of the flying capacitor, and the cathode of the Zener diode is coupled to the output end of the charge pump and the gate of the first NMOS tube respectively; The drain of the first NMOS tube is coupled to the output end of the charge pump, and the source of the first NMOS tube is coupled to the power supply end of the driver.

5. The driving circuit according to claim 1, characterized in that: Also includes a short circuit protection module, the short circuit protection module includes a first resistor and a first diode; The first end of the first resistor receives the adjustable reference voltage, and the second end thereof is respectively coupled to the gate of the high-end source follower NMOS tube and the cathode of the first diode, and the anode of the first diode is coupled to the source of the high-end source follower NMOS tube.

6. The driving circuit according to claim 1, characterized in that: It also includes a current limiting control module, a first end of which is coupled to the gate of the input power tube, and a second end of which is coupled to the first end of the flying capacitor.

7. The driving circuit according to claim 6, characterized in that: The current limiting control module includes N current limiting branches connected in parallel, a current limiting NMOS tube and a switch control unit; The first end of each current limiting branch is coupled to the source of the low-end source follower NMOS tube, the second end of each current limiting branch is respectively coupled to the drain of the pull-down NMOS tube and the drain of the current limiting NMOS tube, the source of the current limiting NMOS tube is coupled to the first end of the flying capacitor, the gate of the current limiting NMOS tube is coupled to the drain of the current limiting NMOS tube, and the switch control unit is respectively coupled to the control end of each current limiting branch to control the on and off of each current limiting branch.

8. The driving circuit according to claim 7, characterized in that: Each current limiting branch includes a current limiting switch and a current limiting resistor which are electrically connected in sequence, and the switch control unit is respectively coupled to the control end of each current limiting switch.

9. A high voltage charge pump, characterized in that: include: An input power tube control module and an input power tube of a drive circuit as claimed in any one of claims 1 to 8.

10. The high voltage charge pump according to claim 9, characterized in that: The high-voltage charge pump further includes: a transmission NMOS tube, an output PMOS tube, a grounding NMOS tube, a flying capacitor, an output capacitor and a general control module; The drain of the input power tube receives the input voltage, and the source thereof is respectively coupled to the first end of the flying capacitor and the drain of the grounded NMOS tube; the gate of the input power tube is coupled to the output end of the input gate control module, and the input end of the input power tube control module is coupled to the first end of the general control module; the gate of the grounded NMOS tube is coupled to the second end of the general control module through the grounded gate control module, and the source thereof is grounded. The source of the output PMOS tube is coupled to the first end of the output capacitor, the drain of the output PMOS tube is coupled to the drain of the transmission NMOS tube and the second end of the flying capacitor respectively, and the gate of the output PMOS tube is coupled to the third end of the general control module through the output gate control module; The source of the transmission NMOS tube receives the input voltage, and the source of the transmission NMOS tube is also coupled to the second end of the output capacitor, the gate of the transmission NMOS tube is coupled to the fourth end of the general control module through the transmission gate control module, and the first end of the output capacitor is used to output the output voltage; The overall control module is used to control the on and off of the input power tube, the transmission NMOS tube, the output PMOS tube and the grounding NMOS tube, so that the voltage value of the output voltage is the target voltage value.

11. The high voltage charge pump according to claim 9, characterized in that: The high voltage charge pump further comprises: A flying voltage detection module, a first end of which is coupled to the first end of the flying capacitor, and a second end of which is coupled to the fifth end of the general control module, and the flying voltage detection module is used to detect the voltage value of the flying capacitor; an output voltage detection module, a first end of which receives an input voltage, a second end of which is coupled to the first end of the output capacitor, and a third end of which is coupled to the sixth end of the main control module, and the output voltage detection module is used to detect a voltage value of the output voltage; The overall control module is also used for: Based on the voltage value of the output voltage and / or the voltage value of the flying capacitor, it is determined whether the charge pump is in a normal working state, wherein: Only when the voltage value of the flying capacitor is maintained within the first set voltage range and the voltage value of the output voltage is higher than the second set voltage value, it is determined that the charge pump is in a normal working state.

12. An electronic device, characterized in that: It comprises the high voltage charge pump as claimed in any one of claims 9 to 11.

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