CN113436586B

CN113436586B - PWM voltage control circuit and method

Info

Publication number: CN113436586B
Application number: CN202110890877.2A
Authority: CN
Inventors: 杨小伟; 林喆
Original assignee: Shanghai Sunmi Technology Group Co Ltd; Citaq Co Ltd
Current assignee: Shanghai Sunmi Technology Group Co Ltd; Citaq Co Ltd
Priority date: 2021-08-04
Filing date: 2021-08-04
Publication date: 2023-04-25
Anticipated expiration: 2041-08-04
Also published as: CN113436586A

Abstract

The invention belongs to the field of linear dimming, and discloses a PWM voltage control circuit and a PWM voltage control method, wherein the PWM voltage control circuit comprises the following steps: the power supply input end is used for inputting voltage signals set according to the peripheral requirements; the PWM input end is used for inputting a PWM signal of a first voltage or a PWM signal of a second voltage; the transistor is connected with the power input end and the PWM input end and is used for being conducted when receiving the PWM signal of the first voltage or being turned off when receiving the PWM signal of the second voltage; the voltage output end is connected with the transistor and is used for outputting a PWM signal of a third voltage when the transistor is turned on; wherein the first voltage is greater than the second voltage; the third voltage is greater than the first voltage. The invention can flexibly and more externally arrange the required voltage level, and can be completed by replacing proper circuit devices, thereby being convenient and low in cost.

Description

PWM voltage control circuit and method

Technical Field

The invention relates to the field of linear dimming, in particular to a PWM voltage control circuit and a PWM voltage control method.

Background

Some device platform devices, control pins of ICs, now require the use of linearly varying levels for enabling regulation. In the market, an adjusting chip is usually added, so that the cost is high, and a simple circuit is selected to overlap and complete the linear adjustment of the backlight brightness.

The voltage provided by some platforms can not meet the requirements of chips on PWM voltage values, and at present, some linear regulation or PWM level boosting circuits in the market are realized through ICs, so that the cost is high, and meanwhile, the voltage required to be regulated up has a limit.

Disclosure of Invention

An object of the present invention is to provide a PWM voltage control circuit and method that solves the above-mentioned problems.

The technical scheme provided by the invention is as follows:

in one aspect, there is provided a PWM voltage control circuit comprising:

the power supply input end is used for inputting voltage signals set according to the peripheral requirements;

the PWM input end is used for inputting a PWM signal of a first voltage or a PWM signal of a second voltage;

the transistor is connected with the power input end and the PWM input end and is used for being conducted when receiving the PWM signal of the first voltage or being turned off when receiving the PWM signal of the second voltage;

the voltage output end is connected with the transistor and is used for outputting a PWM signal of a third voltage when the transistor is turned on;

wherein the first voltage is greater than the second voltage; the third voltage is greater than the first voltage.

Further preferably, the method comprises:

and the voltage dividing resistor is connected with the power input end and used for dividing the voltage signal.

Further preferably, the method further comprises:

and the RC filter circuit is connected with the PWM input end and the transistor and is used for filtering clutter.

Further preferably, the RC filter circuit includes: a filter resistor and a first capacitor;

the filter resistor is connected with the PWM input end and the transistor;

the first end of the first capacitor is connected with the filter resistor, and the second end of the first capacitor is grounded.

Further preferably, the method further comprises:

and the current limiting resistor is connected with the voltage dividing resistor, the transistor and the voltage output end and is used for limiting the output signal of the voltage output end.

Further preferably, the method further comprises:

and the second capacitor is connected with the current limiting resistor and the voltage output end and is used for forming an RC circuit with the current limiting resistor so that the PWM signal output by the transistor charges the second capacitor, and the voltage output end outputs linear voltage.

Further preferably, a first end of the transistor is connected to the RC filter circuit, a second end of the transistor is grounded, and a third end of the transistor is connected to the power supply input terminal and the voltage output terminal.

A PWM voltage control method, comprising:

inputting a voltage signal set according to the peripheral requirements through a power input end;

inputting a PWM signal of a first voltage or a PWM signal of a second voltage by using a PWM input end;

the PWM signal receiving circuit is connected with the power input end and the PWM input end through a transistor, and is turned on when receiving the PWM signal of the first voltage or turned off when receiving the PWM signal of the second voltage;

the voltage output end is connected with the transistor, and when the transistor is conducted, a PWM signal of a third voltage is output;

Further preferably, the method further comprises:

the second capacitor is connected with the current limiting resistor and the voltage output end, and forms an RC circuit with the current limiting resistor, so that PWM signals output by the transistor charge the second capacitor, and the voltage output end outputs linear voltage.

The PWM voltage control circuit and the PWM voltage control method have at least the following technical effects:

the invention can flexibly and more externally arrange the required voltage level, and can be completed by replacing proper circuit devices, thereby being convenient and low in cost.

Drawings

The invention is described in further detail below with reference to the attached drawings and detailed description:

FIG. 1 is a schematic diagram of one embodiment of a PWM voltage control circuit of the present invention;

FIG. 2 is a schematic diagram of another embodiment of a PWM voltage control circuit of the present invention;

FIG. 3 is a schematic diagram of one embodiment of a PWM voltage control method of the present invention;

FIG. 4 is a diagram of the normal operation signals of the present invention;

FIG. 5 is a waveform diagram of the normal operation of the present invention;

fig. 6 is a schematic diagram of one embodiment of a PWM voltage control method of the present invention.

Detailed Description

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

For the sake of simplicity of the drawing, the parts relevant to the present invention are shown only schematically in the figures, which do not represent the actual structure thereof as a product. Additionally, in order to simplify the drawing for ease of understanding, components having the same structure or function in some of the drawings are shown schematically with only one of them, or only one of them is labeled. Herein, "a" means not only "only this one" but also "more than one" case.

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

In this context, it should be noted that the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, unless explicitly stated or limited otherwise; 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 invention will be understood in specific cases by those of ordinary skill in the art.

In addition, in the description of the present application, the terms "first," "second," and the like are used merely to distinguish between descriptions and are not to be construed as indicating or implying relative importance.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will explain the specific embodiments of the present invention with reference to the accompanying drawings. It is evident that the drawings in the following description are only examples of the invention, from which other drawings and other embodiments can be obtained by a person skilled in the art without inventive effort.

Example 1

In one aspect, as shown in fig. 1, the present invention provides a PWM voltage control circuit, comprising:

and the power supply input end 1 is used for inputting a voltage signal set according to the peripheral requirements.

And a PWM input terminal 2 for inputting a PWM signal of the first voltage or a PWM signal of the second voltage.

And the transistor 3 is connected with the power input end and the PWM input end and is used for being conducted when receiving the PWM signal of the first voltage or being turned off when receiving the PWM signal of the second voltage.

And a voltage output terminal 4 connected with the transistor and used for outputting a PWM signal of a third voltage when the transistor is turned on.

By way of example, as shown in FIG. 2, because the PWM voltage of some platforms themselves is relatively low (say 1.8V/3.3V), a higher voltage PWM, or a linear voltage value (e.g., 0V-VIN) can be achieved by the transistor (Q1105).

In this embodiment, by setting the power input terminal (VIN), PWM of a voltage close to the magnitude of the power input terminal (VIN) can be obtained on the D-electrode of the transistor (Q1105).

The invention can flexibly increase the voltage level required by the peripheral equipment, can be completed by replacing proper circuit devices, and is convenient and low in cost.

Example two

Based on the above embodiments, the same parts as those of the above embodiments are not repeated in this embodiment, and a PWM voltage control circuit is provided in this embodiment, as shown in fig. 2 to 5, and specifically includes:

In this embodiment, further comprising: and the voltage dividing resistor is connected with the power input end and used for dividing the voltage signal.

Illustratively, as shown in FIG. 2, a voltage dividing resistor (R1138) is coupled to the power input (VIN) for dividing the input voltage.

The embodiment further includes:

Illustratively, as shown in fig. 2, the resistor (R1140) and the capacitor (C3305) form an RC filter circuit for filtering the PWM signal input from the PWM input terminal.

The RC filter circuit includes: a filter resistor and a first capacitor; the filter resistor is connected with the PWM input end and the transistor; the first end of the first capacitor is connected with the filter resistor, and the second end of the first capacitor is grounded.

One end of the first capacitor (C3305) is connected with the filter resistor (R1140), and the other end of the first capacitor is grounded. The filter resistor (R1140) is also connected to the G pole of the transistor (Q1105).

In this embodiment, further comprising:

Illustratively, as shown in FIG. 2, the current limiting resistor (R1139) acts as a current limiting resistor when the capacitor (C3303) is not connected, and as a charge delay resistor after the capacitor (C3303) is connected.

In this embodiment, it is preferable that:

Illustratively, as shown in FIG. 2, the second capacitor (C3303) is coupled to the current limiting resistor (R1139) and also to the Voltage Output (VOUT).

Specifically, the charging of the second capacitor (C3303) by PWM on the transistor (Q1105) can be achieved through an RC circuit composed of the current limiting resistor (R1139) and the second capacitor (C3303), thereby obtaining a voltage.

Illustratively, regarding the circuit critical devices:

the selection of the transistor (Q1105) needs to take into account the GS voltage and DS voltage of the transistor (Q1105). (i.e., the maximum value of the input PWM is greater than the Gsth on-voltage.)

The current limiting resistor (R1139) and the second capacitor (C3303) RC combination are linked to the duty of the PWM, the frequency, and influence the voltage output terminal VOUT () as the value of the linear output voltage.

The second capacitance (C3303) is conventionally recommended to be 1UF, and the current limiting resistance (R1139) to be 2.2k.

In this embodiment, preferably, a first end of the transistor is connected to the RC filter circuit, a second end of the transistor is grounded, and a third end of the transistor is connected to the power input terminal and the voltage output terminal.

In this embodiment, by adjusting the duty of the PWM signal input from the PWM input terminal, the voltage output terminal (VOUT) can be output to the second capacitor (C3303) with different voltage values, thereby realizing linear adjustment of the peripheral.

In addition, the second capacitor (C3303) may be optionally disconnected according to the requirement, and if the second capacitor (C3303) is removed, a stable PWM (maximum value smaller than the amplitude of the power input terminal (VIN)) may be obtained at the voltage output terminal (VOUT), and the duty cycle is opposite to the PWM outputted.

In this embodiment, the PWM signal output from the power input terminal (VOUT) is converted into a control signal to control the load chip switch.

In this embodiment, the present invention is used to convert the lower level PWM to the higher level PWM, and the highest level depends on the withstand voltage of the power input terminal (VIN) and UDS (drain-source voltage), such as 12V, 15V, etc.

The invention can also convert PWM signals to variable voltage values for control of peripherals/loads (e.g., devices that are only operated with linear voltages). Compared with the IC scheme in the market, the method is simpler, cheaper and more convenient.

Example III

The invention also provides a PWM voltage control method, as shown in figures 3 and 6, comprising the following steps:

s100, a voltage signal set according to the requirement of the peripheral is input through a power input terminal.

S200 inputs a PWM signal of a first voltage or a PWM signal of a second voltage using a PWM input terminal.

S300 is connected with the power input end and the PWM input end through a transistor, and is conducted when receiving the PWM signal of the first voltage or is turned off when receiving the PWM signal of the second voltage.

S400 is connected to the transistor by a voltage output terminal, and outputs a PWM signal of a third voltage when the transistor is turned on.

In this embodiment, further comprising:

In the foregoing embodiments, the descriptions of the embodiments are focused on, and the parts of a certain embodiment that are not described or depicted in detail may be referred to in the related descriptions of other embodiments.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus/electronic device and method may be implemented in other manners. The apparatus/electronic device embodiments described above are exemplary only, and the modules or elements are exemplary only, as there may be additional divisions of logic functions, actual implementations, exemplary, multiple elements or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection via interfaces, devices or units, which may be in electrical, mechanical or other forms.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

It should be noted that the above embodiments can be freely combined as needed. The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims

1. A PWM voltage control circuit, comprising:

when a second capacitor is connected between the transistor and the voltage output end, different voltage values are output by adjusting the duty ratio of the PWM signal input by the PWM input end so as to linearly adjust the external device;

when the second capacitor is not connected between the transistor and the voltage output end, outputting a PWM signal with the maximum value smaller than the voltage amplitude of the power input end, wherein the duty ratio of the PWM signal is opposite to that of the input PWM signal;

2. The PWM voltage control circuit of claim 1, comprising:

3. The PWM voltage control circuit of claim 2, further comprising:

4. A PWM voltage control circuit according to claim 3, wherein the RC filter circuit comprises: a filter resistor and a first capacitor;

the filter resistor is connected with the PWM input end and the transistor;

5. The PWM voltage control circuit of claim 4, further comprising:

6. The PWM voltage control circuit of claim 5, further comprising:

7. The PWM voltage control circuit according to any one of claims 1-6, wherein a first terminal of the transistor is connected to an RC filter circuit, a second terminal of the transistor is grounded, and a third terminal of the transistor is connected to the power supply input terminal and the voltage output terminal.

8. A PWM voltage control method, comprising:

9. The PWM voltage control method according to claim 8, further comprising: