CN220874423U

CN220874423U - Current-expanding type negative voltage generation circuit based on self-oscillation

Info

Publication number: CN220874423U
Application number: CN202320110651.0U
Authority: CN
Inventors: 邱序涛; 代高强; 代同振; 何凤喜; 张帅
Original assignee: Chengdu Fujin Power Semiconductor Technology Development Co ltd
Current assignee: Chengdu Fujin Power Semiconductor Technology Development Co ltd
Priority date: 2022-09-26
Filing date: 2022-09-26
Publication date: 2024-04-30
Anticipated expiration: 2032-09-26
Also published as: CN219499222U; CN218162220U

Abstract

The utility model discloses a current-expanding type negative voltage generation circuit based on self-oscillation, which belongs to the technical field of power supply circuits and comprises the following components: the self-oscillation module is used for outputting high-low conversion level; the totem pole module is connected with the output end of the self-oscillation module, changes the switch state under the action of high-low conversion level and generates a switch driving signal; and the voltage reducing circuit module is connected with the output end of the totem pole module, and a capacitor in the voltage reducing circuit module is charged and discharged under the action of high-low conversion level and switch driving signals so as to realize voltage reducing treatment. The negative voltage generating circuit introduces the totem pole module, has a current expansion effect, and further improves the output load capacity; the negative voltage output is realized without adopting a special chip on the basis of not introducing an auxiliary power supply, peripheral components are reduced, the cost overhead is reduced, and the circuit size is small; different negative pressure outputs can be realized by adjusting the depressurization level of the negative pressure generating module, and the negative pressure output flexibility is improved.

Description

Current-expanding type negative voltage generation circuit based on self-oscillation

The utility model discloses a divisional application of patent application No. 2022225477518 of 2022, 09 and 26 of month, named as a negative voltage generating circuit based on self-oscillation.

Technical Field

The utility model relates to the technical field of power supply circuits, in particular to a current-spreading type negative voltage generation circuit based on self-oscillation.

Background

In some power circuit applications, positive and negative power supplies are needed, such as driving IGBTs, while some power circuits can only provide a single power supply, thus requiring an additional new negative power supply. The current common negative power supply introduction method is to add an isolated power supply, wherein the isolated power supply is grounded positively, and the isolated power supply is negative to negative power supply output so as to introduce a negative power supply. In addition, negative power supply output can be achieved by adding a negative power supply chip. However, the adoption of a general isolated power supply to generate a negative power supply increases the volume of a power circuit and has high cost; the adoption of a special chip to generate a negative power supply also greatly increases the cost.

Disclosure of utility model

The utility model aims to overcome the problems in the prior art and provides a current-spreading type negative voltage generation circuit based on self-oscillation.

The aim of the utility model is realized by the following technical scheme: a current spreading type negative voltage generating circuit based on self-oscillation, the circuit comprising: the self-oscillation module is used for outputting high-low conversion level; the totem pole module is connected with the output end of the self-oscillation module, changes the switch state under the action of high-low conversion level and generates a switch driving signal; and the voltage reducing circuit module is connected with the output end of the totem pole module, and a capacitor in the voltage reducing circuit module is charged and discharged under the action of high-low conversion level and switch driving signals so as to realize voltage reducing treatment.

In an example, the self-oscillation module is a self-oscillation subcircuit configured based on an operational amplifier.

In an example, the self-oscillation subcircuit comprises an operational amplifier, wherein the homodromous input end of the operational amplifier is connected with a resistor R2, one end of the resistor R2 is connected with a power supply VCC, and the other end of the resistor R2 is grounded through a resistor R5; the homodromous input end of the operational amplifier is also sequentially connected with a resistor R4, a resistor R1 and a resistor R7, the other end of the resistor R7 is connected to a power supply VCC, one point is led out between the resistor R1 and the resistor R7 and is connected to the output end of the operational amplifier, and the output end of the operational amplifier is connected with the totem pole module;

The reverse input end of the operational amplifier is connected with a resistor R3, one end of the resistor R3 is connected between a resistor R4 and a resistor R1, and the other end of the resistor R3 is connected with a grounding capacitor C3.

In an example, the totem pole module includes an NPN triode Q1 and a PNP triode Q2, an emitter of the triode Q1 is connected with an emitter of the triode Q2, a base of the triode Q1 is connected with a base of the triode Q2, a point is led out between the base of the triode Q1 and the base of the triode Q2 and connected to an output end of the operational amplifier through a resistor R6, a collector of the triode Q1 is connected with a power supply VCC, and a collector of the triode Q2 is grounded.

In an example, the buck circuit module is a one-stage buck sub-circuit or a multi-stage buck sub-circuit.

In an example, the primary step-down sub-circuit is a primary step-down sub-circuit, and includes a capacitor C2, a diode D1, a diode D4, and a capacitor C4;

The capacitor C2 is connected with the output end of the totem pole module, the other end of the capacitor C2 is connected with the anode of the diode D4, and the cathode of the diode D4 is grounded; the cathode of the diode D1 is connected between the capacitor C2 and the anode of the diode D4, the anode of the diode D1 is connected with the grounding capacitor C4, and a negative pressure output end VO is led out between the anode of the diode D1 and the grounding capacitor C4.

In an example, the voltage reducing circuit module is a secondary voltage reducing sub-circuit, and comprises a primary voltage reducing sub-circuit and a secondary voltage reducing sub-circuit, wherein the primary voltage reducing sub-circuit is matched with the secondary voltage reducing sub-circuit to perform secondary voltage reducing treatment on the circuit voltage.

In an example, the primary buck sub-circuit includes a capacitor C2, a diode D1, a diode D4, and a capacitor C4; the secondary step-down subcircuit comprises a diode D3, a grounding capacitor C5, a diode D2 and a capacitor C1 which are connected in sequence;

The capacitor C2 is connected with the output end of the totem pole module, the other end of the capacitor C2 is connected with the anode of the diode D4, and the cathode of the diode D4 is grounded; the anode of the diode D1 is connected with the grounding capacitor C4, and a negative pressure output end is led out between the anode of the diode D1 and the grounding capacitor C4;

The cathode of the diode D3 is connected between the capacitor C2 and the anode of the diode D4, and the anode of the diode D2 is connected with the cathode of the diode D1; one end of the capacitor C1 is connected between the capacitor C2 and the anode of the diode D4 (one end of the capacitor C1 is connected between the cathode of the diode D3 and the anode of the diode D4), and the other end is connected between the anode of the diode D2 and the cathode of the diode D1.

Specifically, in cooperation with the specific self-oscillation sub-circuit (oscillator) and totem pole module circuit structure disclosed in the above examples, the working principle of the two-stage step-down sub-circuit at this time is as follows:

When the self-excited oscillation sub-circuit does not work, the VO output voltage is 0V, when the oscillator starts to work, if the output of the first period of the oscillator is low, Q1 is closed, Q2 is opened, D3, D2, D1 and D4 are cut off, and the VO output voltage is 0V;

When the output of the oscillator is changed from low to high, Q1 is switched on, Q2 is switched off, D3, D2 and D1 are switched off, D4 is switched on, VCC charges C2 through Q1 and D4, when the voltage on the C2 capacitor reaches VCC-VQ1-VD4, ending, and the VO output voltage is 0V;

When the output of the oscillator is changed from high to low, Q1 is closed, Q2 is on, D3, D2 and D1 are on, D4 is off, a capacitor C2 charges capacitors C5 and C4 through Q2, D3, D2 and D1, when the voltage on the capacitor C5 reaches (VD 3+VD4+VQ1+VQ 2-VCC), the voltage on the capacitor C4 reaches (VD 3+VD2+VD1+VD4+VQ1+VQ 2-VCC), and the voltage output by VO is (VD 3+VD2+VD1+VD4+VQ1+VQ 2-VCC);

When the output of the oscillator is changed from low to high, Q1 is on, Q2 is off, D3 and D1 are off, D2 and D4 are on, VCC charges C2 through Q1 and D4, VCC ends when the voltage on the C2 capacitor reaches (VCC-VQ 1-VD 4), VCC charges C1 through Q1, C2, D2 and C5, when the voltage on the C1 capacitor reaches (VD 3+VD2+VQ1 +VQ2-VCC), and the VO output voltage is (VD 3+VD2+VD1+VD4+VQ1 +VQ2-VCC);

When the output voltage of the capacitor C5 reaches (VD3+VD4+VQ1+VQ2-VCC), the voltage of the capacitor C4 is up to (VD3+VD2+VD1+VD4+2 VQ1+2-2 VCC), the VO output voltage is (VD3+VD2+VD1+VD4+2+VQ1+2+2 VQ1+2-2 VCC), and the oscillator keeps the voltage on the capacitor C4 stable by continuously changing the output level, so as to achieve the purpose of stabilizing the output negative voltage.

In an example, the step-down circuit module is a three-stage step-down sub-circuit, and includes a primary step-down sub-circuit, a secondary step-down sub-circuit, and a tertiary step-down sub-circuit, where the primary step-down sub-circuit, the secondary step-down sub-circuit, and the tertiary step-down sub-circuit cooperate to perform three-stage step-down processing on the circuit voltage.

In an example, the primary buck sub-circuit includes a capacitor C2, a diode D1, a diode D4, and a capacitor C4; the secondary step-down subcircuit comprises a diode D3, a grounding capacitor C5, a diode D2 and a capacitor C1 which are connected in sequence; the three-time voltage reduction subcircuit comprises a diode D6, a grounding capacitor C7, a diode D5 and a capacitor C6 which are connected in sequence;

The cathode of the diode D3 is connected between the capacitor C2 and the anode of the diode D4, and the anode of the diode D2 is connected with the cathode of the diode D1; one end of the capacitor C1 is connected between the capacitor C2 and the anode of the diode D4, and the other end of the capacitor C1 is connected between the anode of the diode D2 and the cathode of the diode D1;

The cathode of the diode D6 is connected with the anode of the diode D2, and the anode of the diode D5 is connected with the cathode of the diode D1; one end of the capacitor C6 is connected between the anode of the diode D2 and the cathode of the diode D6, and the other end is connected between the anode of the diode D5 and the cathode of the diode D1.

It should be further noted that the technical features corresponding to each example in the self-oscillation-based current-spreading type negative voltage generation circuit may be combined with each other or replaced to form a new technical scheme.

Compared with the prior art, the utility model has the beneficial effects that:

The negative voltage generating circuit introduces the totem pole module, has a current expansion effect, and further improves the output load capacity; the utility model does not need to adopt a special chip (an isolated power supply or a negative power supply chip), realizes negative voltage output on the basis of not introducing an auxiliary power supply, reduces peripheral components, greatly reduces cost expenditure and has small circuit volume. Different negative pressure outputs can be realized by adjusting the depressurization level of the negative pressure generating module, and the negative pressure output flexibility is improved. In addition, compared with the existing isolation power supply technology, the utility model reduces the design of the isolation power supply, reduces the design difficulty, is convenient for design, shortens the development period, improves the product reliability, reduces the circuit volume and improves the power density.

Drawings

The following detailed description of the present utility model is provided in connection with the accompanying drawings, which are included to provide a further understanding of the utility model, and in which like reference numerals are used to designate like or similar parts throughout the several views, and in which are shown by way of illustration of the utility model and not limitation thereof.

FIG. 1 is a schematic diagram of a primary buck sub-circuit with current spreading capability of the present utility model;

FIG. 2 is a schematic diagram of a two-stage buck sub-circuit with current spreading capability according to the present utility model;

Fig. 3 is a schematic diagram of a three-stage buck sub-circuit with current spreading capability in accordance with the present utility model.

Detailed Description

The following description of the embodiments of the present utility model will be made apparent and fully understood from the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be noted that directions or positional relationships indicated as being "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are directions or positional relationships described based on the drawings are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or elements to be referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Further, ordinal words (e.g., "first and second," "first through fourth," etc.) are used to distinguish between objects, and are not limited to this order, but rather are not to be construed to indicate or imply relative importance.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

In addition, the technical features of the different embodiments of the present utility model described below may be combined with each other as long as they do not collide with each other.

The utility model also comprises a self-oscillation-based current-spreading negative voltage generation circuit, which comprises a self-oscillation module, a totem pole module and a voltage reduction circuit module which are sequentially connected. The self-oscillation module can output high-low conversion level to control the switching state of a switch in the totem pole module under the condition that external oscillation is not added, so that the capacitor in the voltage reduction circuit module is controlled to charge and discharge, and the voltage reduction purpose is achieved. The totem pole module is the existing totem pole driving circuit, the on-off state of the self-switch is controlled based on the low-current level signal with the high-low change output by the self-oscillation module, and therefore charging and discharging of the ampere level of the capacitor are achieved, and the output load capacity is improved. The voltage reduction circuit module is designed based on basic electronic components, specifically based on capacitor charge and discharge characteristics, and comprises a capacitor and a unidirectional conduction switch (basic electronic components), wherein the capacitor is charged and discharged under the cooperation of high-low conversion level and switch driving signals, namely, one-stage or multi-stage voltage reduction is performed based on reference voltage, and negative pressure output is further realized.

In one example, the self-oscillation module is a self-oscillation subcircuit configured based on an operational amplifier. Specifically, as shown in fig. 1-3, the self-oscillation subcircuit comprises an operational amplifier, wherein the homodromous input end of the operational amplifier is connected with a resistor R2, one end of the resistor R2 is connected with a power supply VCC, and the other end of the resistor R2 is grounded through a resistor R5; the homodromous input end of the operational amplifier is also sequentially connected with a resistor R4, a resistor R1 and a resistor R7, the other end of the resistor R7 is connected to a power supply VCC, one point is led out between the resistor R1 and the resistor R7 and is connected to the output end of the operational amplifier, and the output end of the operational amplifier is connected with the totem pole module; the reverse input end of the operational amplifier is connected with a resistor R3, one end of the resistor R3 is connected between a resistor R4 and a resistor R1, and the other end of the resistor R3 is connected with a grounding capacitor C3. Further, the self-oscillation module can generate a signal (high-low conversion level) of a fixed frequency without external oscillation, and the voltage thereof is the power supply voltage VCC when the signal output is high, and the voltage thereof is the ground voltage when the signal output is low.

In an example, the totem pole module includes an NPN triode Q1 and a PNP triode Q2, wherein an emitter of the triode Q1 is connected with an emitter of the triode Q2, and a point is led out between the emitter of the triode Q1 and the emitter of the triode Q2 as an output end of the totem pole module; the base electrode of the triode Q1 is connected with the base electrode of the triode Q2, and a point is led out between the base electrode of the triode Q1 and the base electrode of the triode Q2 to serve as an input end of the totem pole module; the collector of the triode Q1 is connected with a power supply VCC, and the collector of the triode Q2 is grounded; more specifically, the output end of the operational amplifier is connected between the base electrode of the triode Q1 and the base electrode of the triode Q2 through a resistor R6, and when the self-oscillation module outputs high and low levels alternately, the triode Q1 and the triode Q2 are conducted alternately.

In an example, the voltage-reducing circuit module is a one-stage voltage-reducing sub-circuit or a multi-stage voltage-reducing sub-circuit, preferably a multi-stage voltage-reducing sub-circuit, and at this time, the magnitude of the output negative voltage can be adjusted by adjusting the voltage-reducing multiple of each stage of voltage-reducing sub-circuit and the device parameters (such as capacitance parameters) in the voltage-reducing sub-circuit, so that the voltage-reducing flexibility is improved.

In an example, the primary voltage-reducing sub-circuit is a primary voltage-reducing sub-circuit, and as shown in fig. 1, includes a capacitor C2, a diode D1, a diode D4, and a capacitor C4; the capacitor C2 is connected with the output end of the totem pole module, the other end of the capacitor C2 is connected with the anode of the diode D4, and the cathode of the diode D4 is grounded; the cathode of the diode D1 is connected between the capacitor C2 and the anode of the diode D4, the anode of the diode D1 is connected with the grounding capacitor C4, and a negative pressure output end VO is led out between the anode of the diode D1 and the grounding capacitor C4.

In an example, the voltage reducing circuit module is a secondary voltage reducing sub-circuit, and comprises a primary voltage reducing sub-circuit and a secondary voltage reducing sub-circuit, wherein the primary voltage reducing sub-circuit is matched with the secondary voltage reducing sub-circuit to perform secondary voltage reducing treatment on the circuit voltage. Specifically, as shown in fig. 1, the primary buck sub-circuit structure is as described above by way of example; as shown in fig. 2, the secondary step-down sub-circuit includes a diode D3, a grounded capacitor C5, a diode D2, and a capacitor C1 connected in sequence; the cathode of the diode D3 is connected between the capacitor C2 and the anode of the diode D4, and the anode of the diode D2 is connected with the cathode of the diode D1; one end of the capacitor C1 is connected between the capacitor C2 and the anode of the diode D4 (one end of the capacitor C1 is connected between the cathode of the diode D3 and the anode of the diode D4), and the other end is connected between the anode of the diode D2 and the cathode of the diode D1. In this example, the voltage of the capacitor C1 is further superimposed from the primary step-down to the secondary step-down, and after the primary step-down is completed, the capacitor C1 is continuously charged, so as to implement the secondary step-down.

More specifically, a two-stage buck power supply with current spreading performance is provided, and the circuit structure of the self-oscillation subcircuit (oscillator) and the totem pole module is matched with the above example, the circuit principle is shown in fig. 2, VCC is 5V, VO voltage is required to be output to be-7.2±1v, diode voltage drop is 0.7V, and VQ1 and VQ2 voltages are ignored. The main operation is as follows.

1. VCC supplies power, the oscillator starts working, if the oscillation starts the oscillator output to be low, Q1 is closed, Q2 is opened, D3, D2, D1 and D4 are cut off, and the VO output is 0V.

2. If the oscillation starts and the oscillator output is high, Q1 is on, Q2 is off, D3, D2 and D1 are off, D4 is on, VCC charges C2 through Q1 and D4, and when the voltage on the C2 capacitor reaches 4.3V, the oscillation ends, and the VO output voltage is 0V.

3. When the output of the oscillator is changed from high to low, Q1 is closed, Q2 is on, D3, D2 and D1 are on, D4 is off, capacitor C2 charges capacitors C5 and C4 through Q2, D3, D2 and D1, when the voltage on the capacitor C5 reaches-3.6V, the voltage on the capacitor C4 reaches-2.2V, the voltage is ended, and the output voltage of VO is-2.2V.

4. When the output of the oscillator is changed from low to high, Q1 is on, Q2 is off, D3 and D1 are off, D2 and D4 are on, VCC charges C2 through Q1 and D4, VCC charges C1 through Q1, C2, D2 and C5 when the voltage on the C2 capacitor reaches 4.3V, and the VO output voltage is-2.2V when the voltage on the C1 capacitor reaches 3.6V.

5. When the output of the oscillator is changed from high to low, Q1 is closed, Q2 is opened, D3 and D1 are conducted, D2 and D4 are cut off, C2 charges capacitor C5 through Q2 and D3, C2 and C1 charges capacitor C4 through Q2 and D1, when the voltage on capacitor C5 reaches-3.6V and the voltage on capacitor C4 reaches-7.2V, the voltage is ended, and the VO output voltage is-7.2V. The oscillator continuously changes the output level to control the switching of Q1 and Q2, so as to realize charging and discharging to maintain the voltage stability on the capacitor C4 and ensure the stable negative pressure output of VO.

In an example, the voltage reducing circuit module is a three-stage voltage reducing sub-circuit, and comprises a primary voltage reducing sub-circuit, a secondary voltage reducing sub-circuit and a tertiary voltage reducing sub-circuit, wherein the primary voltage reducing sub-circuit, the secondary voltage reducing sub-circuit and the tertiary voltage reducing sub-circuit are mutually matched to perform three-stage voltage reducing treatment on circuit voltage. Specifically, the primary voltage-reducing sub-circuit and the secondary voltage-reducing sub-circuit are structured as described in the above examples, and the tertiary voltage-reducing sub-circuit comprises a diode D6, a grounding capacitor C7, a diode D5 and a capacitor C6 which are connected in sequence; the cathode of the diode D6 is connected with the anode of the diode D2, and the anode of the diode D5 is connected with the cathode of the diode D1; one end of the capacitor C6 is connected between the anode of the diode D2 and the cathode of the diode D6, and the other end is connected between the anode of the diode D5 and the cathode of the diode D1. In this example, the voltage of the capacitor C6 is further superimposed from the second step-down to the third step-down, and after the second step-down is completed, the capacitor C3 is continuously charged, so as to implement the third step-down.

More specifically, a three-stage buck power supply application with current spreading performance is provided, and the circuit structure of the self-oscillation subcircuit (oscillator) is matched with the above example, the circuit principle is shown in fig. 3, VCC is 5V, the required output VO voltage is-10.8±1v, the diode drop is 0.7V, and the voltages VQ1 and VQ2 are negligible. The main operation is as follows

1. VCC supplies power, the oscillator starts working, if the oscillation starts the oscillator output to be low, Q1 is closed, Q2 is opened, D3, D2, D6, D4, D5 and D1 are cut off, and the VO output is 0V.

2. If the oscillation starts, the oscillator output is high, Q1 is on, Q2 is off, D3, D2, D6, D5 and D1 are off, D4 is on, VCC charges C2 through Q1 and D4, and when the voltage on the C2 capacitor reaches 4.3V, the oscillation ends, and the VO output voltage is 0V.

3. When the output of the oscillator is changed from high to low, Q1 is closed, Q2 is on, D3, D2, D6, D5 and D1 are on, D4 is off, capacitor C2 charges capacitors C5, C7 and C4 through Q2, D3, D2, D6, D4 and D5, when the voltage on the capacitor C5 reaches-3.6V, the voltage on the capacitor C7 reaches-2.2V, the voltage on the capacitor C4 reaches-0.8V, the voltage is ended, and the voltage of the VO output is-0.8V.

4. When the output of the oscillator is changed from low to high, Q1 is on, Q2 is off, D3, D6 and D1 are off, D2, D4 and D5 are on, VCC charges C2 through Q1 and D4, VCC charges C1 through Q1, C2, D2 and C5 when the voltage on the C2 capacitor reaches 4.3V, VCC charges C6 through C2, C1, D5 and C7 when the voltage on the C1 capacitor reaches 3.6V, and VO output voltage is-0.8V.

5. When the output of the oscillator is changed from high to low, Q1 is closed, Q2 is on, D3, D6 and D1 are conducted, D2, D4 and D5 are cut off, C2 charges capacitor C5 through Q2 and D3, C2 charges capacitor C7 through Q2, D6 and C1, C2 charges capacitor C4 through Q2, D1, C6 and C1, when the voltage on capacitor C5 reaches-3.6V, the voltage on capacitor C7 reaches-7.2V, and the voltage on capacitor C4 reaches-8.6V, the process is finished, and the VO output voltage is-8.6V.

6. When the output of the oscillator is changed from low to high, Q1 is on, Q2 is off, D3, D6 and D1 are off, D2, D4 and D5 are on, VCC charges C2 through Q1 and D4, VCC charges C1 through Q1, C2, D2 and C5, VCC charges C6 through C2, C1, D5 and C7, the voltage on the C2 capacitor reaches 4.3V, the voltage on the C1 capacitor reaches 3.6V, the voltage on the C6 capacitor reaches 3.6V, and the voltage on the VO output voltage is-8.6V.

7. When the output of the oscillator is changed from high to low, Q1 is closed, Q2 is on, D3, D6 and D1 are conducted, D2, D4 and D5 are cut off, C2 charges capacitor C5 through Q2 and D3, C2 charges capacitor C7 through Q2, D6 and C1, C2 charges capacitor C4 through Q2, D1, C6 and C1, when the voltage on capacitor C5 reaches-3.6V, the voltage on capacitor C7 reaches-7.2V, and the voltage on capacitor C4 reaches-10.8V, the process is finished, and the VO output voltage is-10.8V. In the example, the oscillator continuously changes the output level, controls the switching of Q1 and Q2, realizes charging and discharging to maintain the stability of the voltage on the capacitor C4, and ensures the stable negative pressure output of VO.

The foregoing detailed description of the utility model is provided for illustration, and it is not to be construed that the detailed description of the utility model is limited to only those illustration, but that several simple deductions and substitutions can be made by those skilled in the art without departing from the spirit of the utility model, and are to be considered as falling within the scope of the utility model.

Claims

1. A current-spreading type negative voltage generating circuit based on self-oscillation is characterized in that: it comprises the following steps:

the self-oscillation module is used for outputting high-low conversion level;

The totem pole module is connected with the output end of the self-oscillation module, changes the switch state under the action of high-low conversion level and generates a switch driving signal;

And the voltage reducing circuit module is connected with the output end of the totem pole module, and a capacitor in the voltage reducing circuit module is charged and discharged under the action of high-low conversion level and switch driving signals so as to realize voltage reducing treatment.

2. The self-oscillation-based current-spreading type negative voltage generation circuit according to claim 1, wherein: the self-oscillation module is a self-oscillation sub-circuit formed based on an operational amplifier.

3. The self-oscillation-based current-spreading type negative voltage generation circuit according to claim 2, wherein: the self-oscillation subcircuit comprises an operational amplifier, wherein the homodromous input end of the operational amplifier is connected with a resistor R2, one end of the resistor R2 is connected with a power supply VCC, and the other end of the resistor R2 is grounded through a resistor R5; the homodromous input end of the operational amplifier is also sequentially connected with a resistor R4, a resistor R1 and a resistor R7, the other end of the resistor R7 is connected to a power supply VCC, one point is led out between the resistor R1 and the resistor R7 and is connected to the output end of the operational amplifier, and the output end of the operational amplifier is connected with the totem pole module;

4. The self-oscillation-based current-spreading type negative voltage generation circuit according to claim 1, wherein: the totem pole module comprises an NPN triode Q1 and a PNP triode Q2, wherein an emitter of the triode Q1 is connected with an emitter of the triode Q2, a base of the triode Q1 is connected with a base of the triode Q2, a point is led out between the base of the triode Q1 and the base of the triode Q2 and is connected to an output end of the operational amplifier through a resistor R6, a collector of the triode Q1 is connected with a power supply VCC, and a collector of the triode Q2 is grounded.

5. The self-oscillation-based current-spreading type negative voltage generation circuit according to claim 1, wherein: the step-down circuit module is a one-stage step-down sub-circuit or a multi-stage step-down sub-circuit.

6. The self-oscillation-based current-spreading type negative voltage generation circuit according to claim 5, wherein: the primary voltage-reducing sub-circuit is a primary voltage-reducing sub-circuit and comprises a capacitor C2, a diode D1, a diode D4 and a capacitor C4;

7. The self-oscillation-based current-spreading type negative voltage generation circuit according to claim 5, wherein: the voltage reducing circuit module is a secondary voltage reducing sub-circuit and comprises a primary voltage reducing sub-circuit and a secondary voltage reducing sub-circuit, and the primary voltage reducing sub-circuit is matched with the secondary voltage reducing sub-circuit to carry out secondary voltage reducing treatment on circuit voltage.

8. The self-oscillation-based current-spreading type negative voltage generation circuit according to claim 7, wherein: the primary voltage reduction subcircuit comprises a capacitor C2, a diode D1, a diode D4 and a capacitor C4; the secondary step-down subcircuit comprises a diode D3, a grounding capacitor C5, a diode D2 and a capacitor C1 which are connected in sequence;

The cathode of the diode D3 is connected between the capacitor C2 and the anode of the diode D4, and the anode of the diode D2 is connected with the cathode of the diode D1; one end of the capacitor C1 is connected between the capacitor C2 and the anode of the diode D4, and the other end is connected between the anode of the diode D2 and the cathode of the diode D1.

9. The self-oscillation-based current-spreading type negative voltage generation circuit according to claim 5, wherein: the step-down circuit module is a three-stage step-down sub-circuit and comprises a primary step-down sub-circuit, a secondary step-down sub-circuit and a tertiary step-down sub-circuit, wherein the primary step-down sub-circuit, the secondary step-down sub-circuit and the tertiary step-down sub-circuit are mutually matched to perform three-stage step-down treatment on circuit voltage.

10. The self-oscillation-based current-spreading type negative voltage generation circuit according to claim 9, wherein: the primary voltage reduction subcircuit comprises a capacitor C2, a diode D1, a diode D4 and a capacitor C4; the secondary step-down subcircuit comprises a diode D3, a grounding capacitor C5, a diode D2 and a capacitor C1 which are connected in sequence; the three-time voltage reduction subcircuit comprises a diode D6, a grounding capacitor C7, a diode D5 and a capacitor C6 which are connected in sequence;