CN218335986U - Pulse width modulation waveform shaping circuit, light modulation device, and power supply device - Google Patents
Pulse width modulation waveform shaping circuit, light modulation device, and power supply device Download PDFInfo
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- CN218335986U CN218335986U CN202222123273.8U CN202222123273U CN218335986U CN 218335986 U CN218335986 U CN 218335986U CN 202222123273 U CN202222123273 U CN 202222123273U CN 218335986 U CN218335986 U CN 218335986U
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Abstract
The utility model relates to a shaping circuit, a light modulation device and a power supply device of pulse width modulation waveform, which comprises a waveform input interface, a waveform output interface, a peak holding unit and an amplitude detection unit; the waveform input interface receives the pulse width modulation waveform and transmits the pulse width modulation waveform to the peak value holding unit and the amplitude detection unit; the peak value holding unit follows the high level amplitude of the pulse width modulation waveform and generates a power supply signal based on the pulse width modulation waveform; the amplitude detection unit detects the pulse width modulation waveform and outputs a detection signal; the waveform output interface receives and outputs the detection signal. The utility model discloses a set up peak holding unit and track high level amplitude voltage to detect through amplitude detecting element, can accurately obtain actual pulse width signal, avoid signal distortion, when having guaranteed the uniformity and the reliability of product, also greatly reduced cost, and circuit structure is simple.
Description
Technical Field
The utility model relates to a technical field of waveform modulation, more specifically say, relate to a shaping circuit, dimming device and power supply unit of pulse width modulation wave form.
Background
A pulse width modulation waveform (hereinafter referred to as a PWM waveform) has high and low amplitude levels, and has a rising edge and a falling edge. The ideal PWM waveform has amplitude voltage stability with rise and fall times equal to zero. However, in practical application, the amplitude of the PWM waveform fluctuates up and down, and there is a climbing slope in the rising or falling time, which will cause that the detection circuit cannot obtain the correct pulse width of the PWM high-level amplitude after the PWM waveform is output to the detection circuit, so that the whole sampling system has an uncertain error, which affects the control accuracy of the system.
In the existing method, the time or duty ratio of the high-level amplitude pulse width is generally corrected by a compensation method, but when the high-level amplitude and the low-level amplitude of the PWM waveform are not fixed and the rising time or the falling time changes with the high-level amplitude voltage or the low-level amplitude voltage, the time or the duty ratio of the high-level amplitude pulse width is corrected by the compensation method, which is difficult to realize, that is, the deviation between the high-level amplitude pulse width detected by the method and the actual pulse width is large. As shown in fig. 4, what the PWM waveform really needs to detect is the actual pulse width, but the level signal of the detection circuit using the reference ground will cause the detected pulse width signal to be distorted. As shown in fig. 4, the pulse width signal becomes large, and therefore, the duty ratio transmitted to the next stage becomes large, which affects the sampling precision of the system, and the consistency and reliability of the product cannot be guaranteed. In addition, when the method is adopted to correct the time or duty ratio of the high-level amplitude pulse width, the execution mode is quite complex, and the cost is high.
SUMMERY OF THE UTILITY MODEL
The to-be-solved technical problem of the utility model lies in, to prior art's defect, provides a shaping circuit, the device of adjusting luminance and power supply unit of pulse width modulation wave form.
The utility model provides a technical scheme that its technical problem adopted is: a shaping circuit for constructing a pulse width modulated waveform comprising: the device comprises a waveform input interface, a waveform output interface, a peak value holding unit and an amplitude detection unit;
the waveform input interface is used for receiving a pulse width modulation waveform and transmitting the pulse width modulation waveform to the peak holding unit and the amplitude detection unit;
the peak value holding unit is connected with the waveform input interface, is used for following the high level amplitude of the pulse width modulation waveform, and generates a power supply signal based on the pulse width modulation waveform;
the amplitude detection unit is connected with the peak holding unit and the waveform input interface and is used for detecting the pulse width modulation waveform and outputting a detection signal;
the waveform output interface is connected with the amplitude detection unit and used for receiving and outputting the detection signal.
In the pulse width modulation waveform shaping circuit of the present invention, the peak holding unit includes: the charging device comprises a rectifying module and a charging module;
the input end of the rectifying module is connected with the waveform input interface, and the output end of the rectifying module is connected with the charging end of the charging module and connected to the amplitude detection unit.
In the shaping circuit of the pulse width modulation waveform of the present invention, the rectifier module includes: a rectifier diode; the charging module includes: charging a capacitor;
the anode of the rectifier diode is connected with the waveform input interface, and the cathode of the rectifier diode is connected with the first end of the charging capacitor and connected to the amplitude detection unit;
and the second end of the charging capacitor is grounded.
In the shaping circuit of the pwm waveform of the present invention, the amplitude detection unit includes: the protection circuit comprises a current limiting module, a protection module and a switch module;
the input end of the current limiting module is connected with the waveform input interface, the output end of the current limiting module is connected with the control end of the switch module, the input end of the switch module is connected with the peak holding unit, and the output end of the switch module is connected with the waveform output interface;
the first end of the protection module is connected with the control end of the switch module, and the second end of the protection module is connected with the input end of the switch module.
In the pulse width modulation waveform shaping circuit of the present invention, the current limiting module includes: at least one resistor or a plurality of resistors connected in series and parallel;
the protection module includes: a resistor or a plurality of resistors connected in series and parallel.
In the pulse width modulation waveform shaping circuit of the present invention, the current limiting module includes: a current limiting resistor; the protection module includes: a discharge resistor; the switch module includes: an electronic switch;
the input end of the current limiting resistor is connected with the waveform input interface, and the output end of the current limiting resistor is connected with the control end of the electronic switch; the first end of the discharge resistor is connected with the control end of the electronic switch, and the second end of the discharge resistor is connected with the input end of the electronic switch; the input end of the electronic switch is connected with the peak holding unit, and the output end of the electronic switch is connected with the waveform output interface.
In the shaping circuit of the pulse width modulation waveform of the present invention, the electronic switch includes: a triode;
the base electrode of the triode is connected with the output end of the current-limiting resistor, the emitting electrode of the triode is connected with the peak value holding unit, and the collector electrode of the triode is connected with the waveform output interface;
the base electrode of the triode is the control end of the electronic switch, the emitter electrode of the triode is the input end of the electronic switch, and the collector electrode of the triode is the output end of the electronic switch.
In the shaping circuit of the pwm waveform of the present invention, the electronic switch includes: an MOS tube;
the grid electrode of the MOS tube is connected with the output end of the current-limiting resistor, the source electrode of the MOS tube is connected with the peak value holding unit, and the drain electrode of the MOS tube is connected with the waveform output interface;
the grid of MOS pipe is the control end of electronic switch, the source electrode of MOS pipe is the input end of electronic switch, the drain electrode of MOS pipe is the output end of electronic switch.
The utility model also provides a dimming device, include: a shaping circuit for the pulse width modulated waveform as described above.
The utility model also provides a power supply unit, include: a shaping circuit for the pulse width modulated waveform as described above.
Implement the utility model discloses a shaping circuit, the device of adjusting luminance and power supply unit of pulse width modulation wave form have following beneficial effect: the device comprises a waveform input interface, a waveform output interface, a peak holding unit and an amplitude detection unit; the waveform input interface receives the pulse width modulation waveform and transmits the pulse width modulation waveform to the peak value holding unit and the amplitude detection unit; the peak value holding unit follows the high level amplitude of the pulse width modulation waveform and generates a power supply signal based on the pulse width modulation waveform; the amplitude detection unit detects the pulse width modulation waveform and outputs a detection signal; the waveform output interface receives and outputs the detection signal. The utility model discloses a set up peak value and keep unit tracking high level amplitude voltage to detect through amplitude detecting element, can accurately obtain actual pulse width signal, avoid signal distortion, when having guaranteed the uniformity and the reliability of product, also greatly reduced cost, and circuit structure is simple.
Drawings
The invention will be further described with reference to the accompanying drawings and examples, in which:
fig. 1 is a schematic structural diagram of a shaping circuit for pulse width modulation waveforms provided by an embodiment of the present invention;
fig. 2 is a circuit diagram of a shaping circuit for pulse width modulation waveforms provided by an embodiment of the present invention;
fig. 3 is a schematic diagram of a detection waveform of a shaping circuit for pulse width modulation waveforms provided by an embodiment of the present invention;
fig. 4 is a schematic diagram of a pulse width detection waveform of a prior art method.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.
Referring to fig. 1, a schematic structural diagram of an alternative embodiment of a shaping circuit for a pulse width modulation waveform according to the present invention is provided.
Specifically, as shown in fig. 1, the shaping circuit of the pulse width modulation waveform includes: a waveform input interface 11, a waveform output interface, a peak hold unit 12 and an amplitude detection unit 13.
The waveform input interface 11 is configured to receive a pulse width modulated waveform and transmit the pulse width modulated waveform to the peak holding unit 12 and the amplitude detection unit 13.
In some embodiments, the waveform input interface 11 is coupled to an external circuit or device that provides a pulse width modulated waveform (i.e., a PWM waveform) to receive the PWM waveform output by the external circuit or device. The external circuit or device may include, but is not limited to: a microcontroller, an integrated control circuit (e.g., IC), a dimming controller, etc.
The peak hold unit 12 is connected to the waveform input interface 11, and is configured to follow the high level amplitude of the pulse width modulation waveform and generate a power supply signal based on the pulse width modulation waveform.
In some embodiments, as shown in fig. 1, the peak hold unit 12 includes: a rectifying module 121 and a charging module 122. The input end of the rectifying module 121 is connected to the waveform input interface 11, and the output end of the rectifying module 121 is connected to the charging end of the charging module 122 and connected to the amplitude detection unit 13.
The rectifying module 121 is configured to rectify the pulse width modulation waveform, and then send the rectified pulse width modulation waveform to the charging module 122 to charge the charging module 122, and form a power supply signal of the amplitude detecting unit 13 after the charging is completed.
The amplitude detection unit 13 is connected to the peak holding unit 12 and the waveform input interface 11, and is configured to detect a pulse width modulation waveform and output a detection signal.
In some embodiments, as shown in fig. 1, the amplitude detection unit 13 includes: a current limiting module 131, a protection module 132, and a switching module 133.
The input end of the current limiting module 131 is connected to the waveform input interface 11, the output end of the current limiting module 131 is connected to the control end of the switch module 133, the input end of the switch module 133 is connected to the peak holding unit 12, and the output end of the switch module 133 is connected to the waveform output interface; a first end of the protection module 132 is connected to the control end of the switch module 133, and a second end of the protection module 132 is connected to the input end of the switch module 133.
The current limiting module 131 plays a role of limiting current to prevent the switch module 133 from being damaged by an excessive voltage flowing into the switch module 133. The protection module 132 plays a role of protection, and is configured to form a discharge loop with the switch module 133 when the control terminal of the switch module 133 generates an excessive signal, so as to implement current drainage.
Optionally, in some embodiments, the current limiting module 131 includes: at least one resistor or a plurality of resistors connected in series and parallel. That is, the current limiting module 131 may be implemented by a resistor; alternatively, the plurality of resistors may be implemented in series, parallel, or series-parallel.
Optionally, in some embodiments, the protection module 132 includes: a resistor or a plurality of series-parallel resistors. That is, the protection module 132 may be implemented by a resistor; alternatively, the plurality of resistors may be implemented in series, parallel, or series-parallel.
Alternatively, in some embodiments, the switch module 133 may be implemented by an electronic switch.
Optionally, in the embodiment of the present invention, the detection signal output by the amplitude detection unit 13 is a waveform signal with a phase opposite to that of the pulse width modulation waveform. Therefore, in some applications, when the same pulse width modulation waveform signal as the waveform input interface 11 is required, an inverting circuit or an inverter may be added to the subsequent stage circuit of the waveform output interface.
The waveform output interface is connected to the amplitude detection unit 13, and is configured to receive and output the detection signal.
In some embodiments, the waveform output interface is used for transmitting the detection signal output by the amplitude detection unit 13. The waveform output interface can transmit the detection signal to a rear-stage driving circuit, a signal reading circuit (such as an MCU, which may be, but not limited to, an 8-bit or 32-bit single chip microcomputer), and the like.
Referring to fig. 2, fig. 2 is a circuit diagram of an alternative embodiment of a shaping circuit for pulse width modulation waveforms provided by the present invention.
Specifically, as shown IN FIG. 2, IN this embodiment, PWM-IN is a waveform input interface 11, and PWM-OUT is a waveform output interface.
In this embodiment, the rectifying module 121 includes: a rectifier diode D2; the charging module 122 includes: the capacitor C1 is charged.
The anode of the rectifier diode D2 is connected with the waveform input interface 11, and the cathode of the rectifier diode D2 is connected with the first end of the charging capacitor C1 and is connected to the amplitude detection unit 13; the second terminal of the charging capacitor C1 is grounded.
The current limiting module 131 includes: a current limiting resistor R8; the protection module 132 includes: a discharge resistor R7; the switch module 133 includes: an electronic switch.
The input end of the current-limiting resistor R8 is connected with the waveform input interface 11, and the output end of the current-limiting resistor R8 is connected with the control end of the electronic switch; the first end of the discharge resistor R7 is connected with the control end of the electronic switch, and the second end of the discharge resistor R7 is connected with the input end of the electronic switch; the input end of the electronic switch is connected with the peak holding unit 12, and the output end of the electronic switch is connected with the waveform output interface.
Optionally, as shown in fig. 2, in this embodiment, the electronic switch includes: and a transistor Q4. The base electrode of the triode Q4 is connected with the output end of the current limiting resistor R8, the emitting electrode of the triode Q4 is connected with the peak value holding unit 12, and the collecting electrode of the triode Q4 is connected with the waveform output interface; the base electrode of the triode Q4 is the control end of the electronic switch, the emitter electrode of the triode Q4 is the input end of the electronic switch, and the collector electrode of the triode Q4 is the output end of the electronic switch.
Alternatively, in some other embodiments, the electronic switch comprises: and a MOS tube. The grid electrode of the MOS tube is connected with the output end of the current-limiting resistor R8, the source electrode of the MOS tube is connected with the peak value holding unit 12, and the drain electrode of the MOS tube is connected with the waveform output interface; the grid of MOS pipe is the control end of electronic switch, and the source electrode of MOS pipe is the input end of electronic switch, and the drain electrode of MOS pipe is the output end of electronic switch.
When the electronic switch is a triode, a PNP triode is selected; when the electronic switch is an MOS tube, a P-type MOS tube is selected.
As shown in fig. 2, when the PWM waveform is at the falling edge, the base voltage of the transistor Q4 is lower than the emitter voltage (about 0.7V), and at this time, the transistor Q4 is turned on, and the collector thereof outputs a high level signal; when the PWM waveform is at a rising edge, the base voltage of the transistor Q4 is higher than the emitter voltage, the transistor Q4 is not turned off, and the collector thereof outputs a low level signal, so that the PWM-OUT outputs a waveform signal having a phase opposite to that of the waveform signal input by the PWM-IN, and the pulse width of the obtained detection signal is the same as the actual pulse width. As shown in detail in figure 3.
The utility model discloses a set up the shaping circuit of this pulse width modulation wave form, can obtain the pulse width or the duty cycle of the high level amplitude of accurate PWM waveform input, can avoid signal distortion, improved signal detection's sampling precision, guaranteed the uniformity and the reliability of product. Additionally, the utility model discloses circuit structure is simple, realizes with low costsly.
The utility model also provides a device of adjusting luminance, wherein, this device of adjusting luminance can include the embodiment of the utility model discloses a shaping circuit of pulse width modulation wave form.
The utility model also provides a power supply unit, wherein, this power supply unit can include the embodiment of the utility model discloses a shaping circuit of pulse width modulation wave form. Alternatively, the power supply device may include, but is not limited to, an LED driving power supply, an industrial driving power supply, a communication driving power supply, and the like.
The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose of the embodiments is to enable people skilled in the art to understand the contents of the present invention and implement the present invention accordingly, which can not limit the protection scope of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention shall fall within the scope of the claims of the present invention.
Claims (10)
1. A circuit for shaping a pulse width modulated waveform, comprising: the device comprises a waveform input interface, a waveform output interface, a peak holding unit and an amplitude detection unit;
the waveform input interface is used for receiving a pulse width modulation waveform and transmitting the pulse width modulation waveform to the peak holding unit and the amplitude detection unit;
the peak value holding unit is connected with the waveform input interface, is used for following the high level amplitude of the pulse width modulation waveform, and generates a power supply signal based on the pulse width modulation waveform;
the amplitude detection unit is connected with the peak holding unit and the waveform input interface and is used for detecting the pulse width modulation waveform and outputting a detection signal;
the waveform output interface is connected with the amplitude detection unit and used for receiving and outputting the detection signal.
2. The circuit for shaping a pulse width modulated waveform of claim 1, wherein the peak hold unit comprises: the charging device comprises a rectifying module and a charging module;
the input end of the rectifying module is connected with the waveform input interface, and the output end of the rectifying module is connected with the charging end of the charging module and connected to the amplitude detection unit.
3. The pulse width modulated waveform shaping circuit of claim 2, wherein the rectification module comprises: a rectifier diode; the charging module includes: a charging capacitor;
the anode of the rectifier diode is connected with the waveform input interface, and the cathode of the rectifier diode is connected with the first end of the charging capacitor and connected to the amplitude detection unit;
and the second end of the charging capacitor is grounded.
4. The circuit for shaping a pulse width modulated waveform of claim 1, wherein the amplitude detection unit comprises: the protection circuit comprises a current limiting module, a protection module and a switch module;
the input end of the current limiting module is connected with the waveform input interface, the output end of the current limiting module is connected with the control end of the switch module, the input end of the switch module is connected with the peak holding unit, and the output end of the switch module is connected with the waveform output interface;
the first end of the protection module is connected with the control end of the switch module, and the second end of the protection module is connected with the input end of the switch module.
5. The pulse width modulated waveform shaping circuit of claim 4, wherein the current limiting module comprises: at least one resistor or a plurality of resistors connected in series and parallel;
the protection module includes: a resistor or a plurality of series-parallel resistors.
6. The pulse width modulated waveform shaping circuit of claim 4, wherein the current limiting module comprises: a current limiting resistor; the protection module includes: a discharge resistor; the switch module includes: an electronic switch;
the input end of the current-limiting resistor is connected with the waveform input interface, and the output end of the current-limiting resistor is connected with the control end of the electronic switch; the first end of the discharge resistor is connected with the control end of the electronic switch, and the second end of the discharge resistor is connected with the input end of the electronic switch; the input end of the electronic switch is connected with the peak holding unit, and the output end of the electronic switch is connected with the waveform output interface.
7. The pulse width modulated waveform shaping circuit of claim 6, wherein the electronic switch comprises: a triode;
the base electrode of the triode is connected with the output end of the current-limiting resistor, the emitting electrode of the triode is connected with the peak value holding unit, and the collector electrode of the triode is connected with the waveform output interface;
the base electrode of the triode is the control end of the electronic switch, the emitting electrode of the triode is the input end of the electronic switch, and the collector electrode of the triode is the output end of the electronic switch.
8. The pulse width modulated waveform shaping circuit of claim 6, wherein the electronic switch comprises: an MOS tube;
the grid electrode of the MOS tube is connected with the output end of the current-limiting resistor, the source electrode of the MOS tube is connected with the peak value holding unit, and the drain electrode of the MOS tube is connected with the waveform output interface;
the grid of MOS pipe is the control end of electronic switch, the source electrode of MOS pipe is the input end of electronic switch, the drain electrode of MOS pipe is the output end of electronic switch.
9. A dimming device, comprising: the circuit for shaping a pulse width modulated waveform of any one of claims 1-8.
10. A power supply device, comprising: the circuit for shaping a pulse width modulated waveform of any one of claims 1-8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222123273.8U CN218335986U (en) | 2022-08-12 | 2022-08-12 | Pulse width modulation waveform shaping circuit, light modulation device, and power supply device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222123273.8U CN218335986U (en) | 2022-08-12 | 2022-08-12 | Pulse width modulation waveform shaping circuit, light modulation device, and power supply device |
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| Publication Number | Publication Date |
|---|---|
| CN218335986U true CN218335986U (en) | 2023-01-17 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202222123273.8U Active CN218335986U (en) | 2022-08-12 | 2022-08-12 | Pulse width modulation waveform shaping circuit, light modulation device, and power supply device |
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| Country | Link |
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| CN (1) | CN218335986U (en) |
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- 2022-08-12 CN CN202222123273.8U patent/CN218335986U/en active Active
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