CN209747106U - LED differential pressure protection circuit - Google Patents
LED differential pressure protection circuit Download PDFInfo
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- CN209747106U CN209747106U CN201920593629.XU CN201920593629U CN209747106U CN 209747106 U CN209747106 U CN 209747106U CN 201920593629 U CN201920593629 U CN 201920593629U CN 209747106 U CN209747106 U CN 209747106U
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Abstract
This specification provides a LED differential pressure protection circuit, LED differential pressure protection circuit includes: the first sampling circuit is used for sampling the driving voltage of the first path of LED lamp group to obtain a first sampling voltage; the second sampling circuit is used for sampling the driving voltage of the second path of LED lamp set to obtain a second sampling voltage; a comparison circuit for outputting a comparison signal when a voltage difference between the first sampling voltage and the second sampling voltage is greater than a threshold voltage; and the control circuit is used for pulling down the level of the control signal according to the comparison signal, wherein when the level of the control signal is low, the LED lamp bank is controlled to be turned off. The embodiment of the specification can cut off the power supply of the LED lamp group when the voltage deviation is overlarge by monitoring the voltage deviation of the LED lamp group with double-path output, and further realize the differential pressure protection.
Description
Technical Field
the specification relates to a circuit, in particular to an LED differential pressure protection circuit.
background
Currently, because of its advantages of long lifetime, power saving, energy saving, and convenient driving, LEDs (light emitting diodes) are widely used as backlight sources in backlight modules of liquid crystal displays. The existing LED backlight sources of the liquid crystal display include a direct type and a side type. The direct type backlight source is characterized in that a plurality of LEDs are directly arranged below the liquid crystal display screen, the side type backlight source is characterized in that the LEDs are distributed on the periphery of the liquid crystal display screen, and LED light is uniformly guided to the liquid crystal display screen through the light guide plate. The LEDs are connected in series to form different LED lamp groups in a series connection mode, so that a better display effect is achieved.
Because the luminous source used by the LED backlight is formed by connecting a plurality of LEDs in series, the conduction voltage drop Vf values of the LED lamp groups in different strings are different due to the difference of the manufacturing processes of the LEDs. Generally, each string of LED lamp group adopts an independent driving circuit, and because conduction voltage drops of different string of LED lamp groups are different, driving voltages of different string of LED lamp groups can also be different, but larger deviation should not exist between the driving voltages of any two string of LED lamp groups; if the voltage deviation between the two paths of driving voltages exceeds a certain range, the currents flowing through the two LED lamp groups have certain deviation, and further the problem of uneven light distribution is caused. The problem is solved by chip design at present, and chip design has certain limitation, is difficult to adjust according to actual LED circuit, and is unfavorable for satisfying the demand of present many specifications (LED's specification) in the aspect of using.
Disclosure of Invention
to overcome the problems in the related art, the present specification provides a method and apparatus.
According to a first aspect of embodiments herein, there is provided an LED differential pressure protection circuit, comprising:
The first sampling circuit is used for sampling the driving voltage of the first path of LED lamp group to obtain a first sampling voltage;
The second sampling circuit is used for sampling the driving voltage of the second path of LED lamp set to obtain a second sampling voltage;
A comparison circuit for outputting a comparison signal when a voltage difference between the first sampling voltage and the second sampling voltage is greater than a threshold voltage;
And the control circuit is used for pulling down the level of the control signal according to the comparison signal, wherein when the level of the control signal is low, the LED lamp bank is controlled to be turned off.
the technical scheme provided by the embodiment of the specification can have the following beneficial effects:
In the embodiment of the specification, a dual-output LED differential pressure protection circuit is provided, which samples driving voltages of two LED lamp sets, generates a comparison signal according to a voltage deviation of the sampling voltages corresponding to the two driving voltages, and sends the comparison signal to a control circuit, and then generates a control signal through the control circuit to control turn-off of the LED lamp set. Through the monitoring of the voltage deviation of the LED lamp bank with double-path output, the power supply of the LED lamp bank can be cut off when the voltage deviation is overlarge, and then the differential pressure protection is realized.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the specification.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present specification and together with the description, serve to explain the principles of the specification.
Fig. 1 is a block diagram of an LED differential pressure protection circuit according to an exemplary embodiment shown in the present specification.
Fig. 2 is a specific framework schematic diagram of an LED differential pressure protection circuit according to an exemplary embodiment shown in the present specification.
Fig. 3 is a circuit schematic diagram of an LED differential pressure protection circuit shown in the present specification according to an exemplary embodiment.
FIG. 4 is a circuit schematic of another LED differential pressure protection circuit shown in accordance with an exemplary embodiment herein.
Detailed Description
Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present specification. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the specification, as detailed in the appended claims.
The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the description. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.
It should be understood that although the terms first, second, third, etc. may be used herein to describe various information, these information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, the first information may also be referred to as second information, and similarly, the second information may also be referred to as first information, without departing from the scope of the present specification. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context.
The following provides a detailed description of examples of the present specification.
as shown in fig. 1, fig. 1 is a schematic diagram of a framework of an LED differential pressure protection circuit according to an exemplary embodiment, where the LED differential pressure protection circuit includes:
The first sampling circuit 1 is used for sampling the driving voltage of the first path of LED lamp group to obtain a first sampling voltage;
The second sampling circuit 2 is used for sampling the driving voltage of the second path of LED lamp set to obtain a second sampling voltage;
the circuit samples driving voltages of two paths of LED lamp sets respectively, the driving voltages of the LEDs are generated by the driving module, one path of driving voltages are added to the LED lamp sets on the corresponding path, the LED lamp sets can be lightened, the multiple groups of LED lamp sets are lightened simultaneously, namely, the LED backlight works, and LED light is guided to the liquid crystal display screen uniformly through the light guide plate. The sampling circuit for acquiring the sampling voltage may be various, and may be a simple resistance type sampling circuit, and of course, the circuit composition of the first sampling circuit is completely the same as that of the second sampling circuit.
A comparison circuit 3 for outputting a comparison signal when a voltage difference between the first sampling voltage and the second sampling voltage is greater than a threshold voltage;
As shown in fig. 2, the comparison circuit includes a voltage stabilizing unit 301 and a controllable switch unit 302, the breakdown voltage or the conduction voltage at two ends of the voltage stabilizing unit can be stabilized within a voltage range with small fluctuation, and the voltage stabilizing unit is internally connected with a backward diode in series to achieve the above-mentioned effect, when the voltage stabilizing unit is turned on, that is, the backward diode is turned on in a breakdown manner, the backward diode works in a voltage stabilizing state, and the conduction voltage or the breakdown voltage drop at two ends of the backward diode is clamped near a fixed voltage value, so that the conduction voltage at two ends of the voltage stabilizing unit is stabilized within a voltage range with small fluctuation.
When the controllable switch unit is switched on or switched off, a switch control signal is required to be triggered, a common simple controllable switch unit is provided with a PNP type triode, when the PNP type triode works, the PNP type triode is required to be provided with a switch control signal or base input voltage, the input voltage meets a certain relation, the controllable switch unit can be triggered to act, and the sum of breakdown voltage drop at two ends of the voltage stabilizing unit and conduction voltage drop at two ends of the controllable switch unit is set as threshold voltage considering that the controllable switch unit has smaller conduction voltage drop after being conducted; when the voltage difference between the first sampling voltage and the second sampling voltage is greater than the threshold voltage, the voltage stabilizing unit is broken down and turned on, and the voltage stabilizing unit generates a switch control signal after being turned on, so that the voltages at the two ends of the controllable switch unit 302 meet the turn-on requirement of the controllable switch unit, and therefore the first sampling circuit 1, the voltage stabilizing unit 301, the controllable switch unit 302 and the second sampling circuit 2 form a conductive loop, and the controllable switch unit 302 outputs the comparison signal after being turned on. Generally, if the device selected by the controllable switch unit is a PNP-type triode, its collector serves as the output terminal of the controllable switch unit, and outputs the comparison signal.
And the control circuit 4 is used for pulling down the level of the control signal according to the comparison signal, wherein when the level of the control signal is low, the LED lamp bank is controlled to be turned off.
One end of the control circuit outputs a control signal Vcontrol; as can be seen from the above analysis, when the voltage difference between the first sampling voltage and the second sampling voltage is smaller than the threshold voltage, and the voltage stabilizing unit does not reach the breakdown condition, the controllable switch unit is not turned on, and no signal is output, that is, under this condition, no comparison signal is transmitted to the control circuit 4, the control circuit does not operate, the control signal at the output end of the control circuit is obtained from the outside and is a control signal Vcontrol with a normal high level, which indicates that the voltage difference between the two LED sampling voltages is not large, and the Vcontrol with the normal high level controls the LED group to operate normally; when the voltage stabilizing unit breaks down and the loop is conducted, and a comparison signal is input to the control circuit 4, the control circuit works internally, the level of the control signal Vcontrol is pulled down, and when the level of the control signal Vcontrol is low, the LED lamp bank is controlled to be turned off; that is to say, when the difference between the two sampling voltages is too large, a comparison signal is generated, and the level of Vcontrol is pulled down, so that the two LED lamp sets are turned off, and thus, the corresponding two LED driving voltages cannot be applied to the two LED lamp sets, thereby realizing the differential pressure protection of the LED lamp sets.
In this embodiment, a two-way output LED differential pressure protection circuit is provided, which samples driving voltages of two LED lamp sets, generates a comparison signal according to a voltage deviation of the sampling voltages corresponding to the two driving voltages, and sends the comparison signal to a control circuit, and then generates a control signal through the control circuit to control turn-off of the LED lamp set. Through the monitoring of the voltage deviation of the LED lamp bank with double-path output, the power supply of the LED lamp bank can be cut off when the voltage deviation is overlarge, and then the differential pressure protection is realized.
In an embodiment, as shown in fig. 3, Vled1 is a driving voltage of a first LED lamp set, Vled2 is a driving voltage of a second LED lamp set, R1 and R3 are connected in series and then grounded to form a first sampling circuit, R2 and R4 are connected in series and then grounded to form a second sampling circuit, where R1 and R2 have the same resistance value, and R3 and R4 have the same resistance value, so that the driving voltages Vled1 and Vled2 are sampled at the same ratio. Generally, the resistances of R3 and R4 are less than the resistances of R1 and R2. The first sampling voltage V1 and the second sampling voltage V2 are obtained by sampling through resistance voltage division.
Consider that in one case, the first sampled voltage V1 is much larger than the second sampled voltage V2 causing bias, or the first sampled voltage V1 is much smaller than the second sampled voltage V2 causing bias as well. In any case, it is desirable that the comparison circuit output a comparison signal. In the comparison circuit, the controllable switch unit includes two PNP transistors (Q1 and Q2) symmetrically arranged, wherein an emitter E of one PNP transistor Q1 receives the first sampling voltage V1, an emitter E of the other PNP transistor Q2 receives the second sampling voltage V2, a base B of the one PNP transistor Q1 is connected to a base B of the other PNP transistor Q2, and a collector C of the one PNP transistor Q1 is connected to a collector C of the other PNP transistor Q2 to output the comparison signal Vcx; the voltage stabilizing unit comprises two symmetrically arranged diode strings, each diode string comprises at least one group of diodes which are connected in series in an inverted mode, one diode string is connected between the base electrode B and the emitting electrode E of one PNP type triode Q1 in parallel, and the other diode string is connected between the base electrode B and the emitting electrode E of the other PNP type triode Q2 in parallel.
In the embodiment shown in fig. 3, it can be seen that diode ZD1 and diode ZD3 are connected in series and in reverse to each other, forming a diode string connected in parallel between base B and emitter E of transistor Q1; the diode ZD2 and the diode ZD4 are connected in series in reverse to each other to form another diode string connected in parallel between the base B and the emitter E of the other triode Q2. The two diode strings are symmetrical to each other, the connection relation and parameters of the diodes in one diode string are the same as those of the diodes in the other diode string, that is, the parameters of the diode ZD1 and the diode ZD2 are the same, and the parameters of the diode ZD3 and the diode ZD4 are the same; therefore, when reverse diodes in the two diode strings are broken down and conducted, the voltage stabilizing values at two ends of each diode string are the same.
As shown in fig. 3, the transistor Q1 and the transistor Q2 are both PNP type (that is, when the emitter voltage of the PNP type transistor is higher than the base voltage, the transistor will be turned on), and based on the characteristics of the PNP type transistor, the following operation principle inside the comparison circuit is analyzed when the deviation between the first sampling voltage V1 and the second sampling voltage V2 is too large, specifically as follows:
when the first sampling voltage V1 is much greater than the second sampling voltage V2 to cause a bias voltage, and a bias voltage difference (V1-V2) between the two is greater than a voltage stabilization value corresponding to the diode string and a conduction voltage drop between the transistors BE, one diode string is necessarily broken down and conducted, when viewed from a current flow direction, the diode strings (ZD2 and ZD4) are broken down and conducted, a current flows in from an emitter E of the transistor Q1, flows out from a base B of the transistor Q1, passes through the broken-down diodes ZD2 and ZD4, and flows to a voltage bit V2 on the second sampling circuit.
when the first sampling voltage V1 is much smaller than the second sampling voltage V2 to cause a bias voltage, and the bias voltage difference (V2-V1) between the two is larger than the corresponding voltage stabilization value of the diode string and the conduction voltage drop between the transistors BE, the diode strings (ZD1 and ZD3) are broken down and conducted when the current flows, a current flows from the V2 voltage bit on the second sampling circuit, the current flows from the emitter E of the transistor Q2, flows from the base B of the transistor Q2, passes through the broken-down diodes ZD1 and ZD3, and flows to the V1 voltage bit on the first sampling circuit.
In an embodiment, the two diode strings are symmetrical to each other, and each diode string has at least one group of diodes connected in reverse series, that is, in a conducting state of the diode string, at least one diode connected in reverse and one diode connected in forward are present in each diode string, and of course, if the threshold voltage needs to be dynamically adjusted according to the magnitude of the deviation to be controlled, the number of diodes in the diode string may be increased or decreased, so as to adjust the conducting voltage drop (voltage stabilizing value) at two ends of the diode string when each diode string is conducted, thereby implementing the control of the magnitude of the deviation of the two driving voltages. In this embodiment, the voltage stabilizing values (breakdown voltage drops) at two ends of the two diode strings can be flexibly adjusted by adjusting the connection relationship and the number of the diodes in the diode strings, so as to flexibly design the voltage difference value of the two-way output driving voltage differential protection, and realize the function of adjustable differential protection.
In the above embodiment, the controllable switch unit is a PNP type transistor, and when the controllable switch unit is turned on, the comparison signal Vcx is output as a high level, that is, when the controllable switch unit is turned on based on the PNP type transistor, the voltage signal output by the collector C of the transistor Q1 or Q2 as the comparison signal Vcx.
In one embodiment, as shown in fig. 3, the control circuit 4 includes an NPN transistor Q3, a base B of the NPN transistor Q3 is connected to the output terminal of the comparison circuit, an emitter E of the NPN transistor Q3 is grounded, a resistor R6 is disposed between the base B and the emitter E of the NPN transistor Q3, and a collector C of the NPN transistor outputs the control signal.
In an embodiment, the control circuit 4 further includes a voltage-reducing resistor R5, one end of the voltage-reducing resistor R5 is connected to the output end of the comparison circuit, and the other end of the voltage-reducing resistor R5 is connected to the base B of the NPN transistor Q3.
In this embodiment, when the controllable switch unit is turned on, if the comparison signal Vcx is at a high level, the base of the NPN transistor Q3 is also at a high level, and if the base voltage of the transistor Q3 is greater than the emitter voltage, the transistor Q3 is turned on; because the collector of the triode Q3 originally has a normally high level Vcontrol connected thereto, when the triode Q3 is turned on, the level of the collector C of the Q3, namely Vcontrol, is pulled down, so that the LED lamp bank in the backlight source is controlled to be turned off, the LED lamp bank is turned off, and the differential pressure protection of the LED lamp bank is realized when the deviation of the driving voltage is overlarge.
In one embodiment, as shown in fig. 4, the control circuit may be an NPN transistor, and may be an N fet. That is, the control circuit 4 includes an N-type field effect transistor M3, the gate G of the N-type field effect transistor M3 is connected to the output terminal of the comparison circuit, the drain D of the N-type field effect transistor is grounded, a resistor R6 is disposed between the gate G and the drain D of the N-type field effect transistor M3, and the source S of the N-type field effect transistor M3 outputs the control signal. The control circuit 4 further comprises a voltage-reducing resistor R5, wherein one end of the voltage-reducing resistor R5 is connected with the output end of the comparison circuit, and the other end is connected with the gate G of the N-type field effect transistor M3. The N-type fet M3 may be an N-channel junction fet, and the circuit principle is the same as that of the NPN-type transistor Q3 in the above embodiment, which is not described herein again.
That is, the control circuit 4 controls the conduction of the switching device according to the comparison signal, wherein the switching device may be an NPN-type transistor or an N-type field effect transistor, which is not limited in this application.
Next, a specific practical example is described to illustrate the design process of two-way LED differential pressure protection. First the threshold voltage, i.e. the differential protection value, is determined. When the voltage difference between V1 and V2 is greater than the threshold voltage, the control signal is pulled down, turning off the LED lamp set in the backlight, assuming the set threshold voltage is 5V. Then, considering the conduction voltage drop of the controllable switch unit, taking an NPN type triode as an example, the conduction voltage drop of the emitter and the base is generally 0.7V, so it is necessary to design the breakdown voltage drop of each diode string to be 4.3V when it is broken down and conducted. Because each diode string at least comprises a group of diodes which are connected in series in a reverse direction, 2 diodes are selected to be connected in series to obtain the diode string to meet the requirement that the breakdown voltage drop of the diode string is about 4.3V when the diode string is broken down and conducted, and the conduction voltage drop of the diode which is conducted in the forward direction is generally 0.7V, the diode with the voltage stabilizing value of about 3.6V when the diode string is conducted in the reverse direction is selected, so that the breakdown voltage drop of the diode string when the diode string is broken down and conducted can be about 4.3V.
Similarly, if the set threshold voltage is 6V, 3 diodes can be selected to be connected in series to obtain a diode string to satisfy the requirement that the breakdown voltage drop when the diode string is breakdown-conducted is about 5.3V, and since the conduction voltage drop of the diode conducting in the forward direction is generally 0.7V, 2 diodes conducting in the forward direction and 1 backward diode can be set, and in this way, one diode with the regulated voltage value of about 3.9V when conducting in the backward direction needs to be selected.
because the types of the diodes are different, the voltage stabilizing values of the diodes during reverse conduction are also different, and the selectable voltage stabilizing values are more, the breakdown voltages at two ends of the diode string can be adjusted by artificially connecting the diodes in series according to the voltage stabilizing values so as to adjust the threshold voltage, namely, the voltage difference value of the voltage difference protection during the output of the two-way LED is adjusted.
In this embodiment, an LED differential pressure protection circuit is provided, which samples driving voltages of two LED lamp sets, generates a comparison signal according to a voltage deviation of the sampling voltages corresponding to the two driving voltages, and sends the comparison signal to a control circuit, and then generates a control signal through the control circuit to control turn-off of the LED lamp set. Through the monitoring of the voltage deviation of the LED lamp bank with double-path output, the power supply of the LED lamp bank can be cut off when the voltage deviation is overlarge, and then the differential pressure protection is realized. Meanwhile, through the design of the diodes in the voltage stabilizing unit, the voltage difference protection of the LED lamp bank with double-path output is realized, the circuit can dynamically adjust the voltage difference value of the voltage difference protection, and the flexibility of the circuit is improved.
The foregoing description has been directed to specific embodiments of this disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may also be possible or may be advantageous.
other embodiments of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This specification is intended to cover any variations, uses, or adaptations of the specification following, in general, the principles of the specification and including such departures from the present disclosure as come within known or customary practice within the art to which the specification pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the specification being indicated by the following claims.
It will be understood that the present description is not limited to the precise arrangements described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present description is limited only by the appended claims.
The above description is only a preferred embodiment of the present disclosure, and should not be taken as limiting the present disclosure, and any modifications, equivalents, improvements, etc. made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.
Claims (8)
1. An LED differential pressure protection circuit, characterized in that the LED differential pressure protection circuit comprises:
The first sampling circuit is used for sampling the driving voltage of the first path of LED lamp group to obtain a first sampling voltage;
the second sampling circuit is used for sampling the driving voltage of the second path of LED lamp set to obtain a second sampling voltage;
A comparison circuit for outputting a comparison signal when a voltage difference between the first sampling voltage and the second sampling voltage is greater than a threshold voltage;
And the control circuit is used for pulling down the level of the control signal according to the comparison signal, wherein when the level of the control signal is low, the LED lamp bank is controlled to be turned off.
2. The LED differential voltage protection circuit according to claim 1, wherein the comparison circuit comprises a voltage stabilization unit and a controllable switch unit, and the threshold voltage is the sum of breakdown voltage drop across the voltage stabilization unit and conduction voltage drop across the controllable switch unit; the voltage stabilizing unit sets breakdown voltage drop at two ends of the voltage stabilizing unit through reverse diodes connected in series inside the voltage stabilizing unit; when the voltage difference value between the first sampling voltage and the second sampling voltage is larger than the threshold voltage, the voltage stabilizing unit is broken down and conducted and generates a switch control signal; and after receiving the switch control signal, the controllable switch unit triggers to be conducted and outputs the comparison signal.
3. The LED differential protection circuit according to claim 2, wherein the controllable switch unit comprises two PNP-type transistors, wherein an emitter of one transistor receives the first sampling voltage, an emitter of the other transistor receives the second sampling voltage, a base of the one transistor is connected to a base of the other transistor, and a collector of the one transistor is connected to a collector of the other transistor to output the comparison signal; the voltage stabilizing unit comprises two diode strings, each diode string comprises at least one group of diodes which are connected in series in an inverted mode, one diode string is connected between the base electrode and the emitting electrode of one triode in parallel, and the other diode string is connected between the base electrode and the emitting electrode of the other triode in parallel.
4. The LED differential pressure protection circuit according to claim 3, wherein the connection relationship and parameters of the plurality of diodes in the one diode string are the same as the connection relationship and parameters of the plurality of diodes in the other diode string.
5. The LED differential pressure protection circuit according to claim 1, wherein the control circuit comprises an NPN-type triode, a base of the triode is connected with the output end of the comparison circuit, an emitter of the triode is grounded, a resistor is arranged between the base and the emitter of the triode, and a collector of the triode outputs the control signal.
6. The LED differential pressure protection circuit of claim 5, wherein the control circuit further comprises a voltage dropping resistor, one end of the voltage dropping resistor is connected with the output end of the comparison circuit, and the other end of the voltage dropping resistor is connected with the base electrode of the triode.
7. the LED differential pressure protection circuit according to claim 1, wherein the control circuit comprises an N-type field effect transistor, a gate of the N-type field effect transistor is connected with the output end of the comparison circuit, a drain of the N-type field effect transistor is grounded, a resistor is arranged between the gate and the drain of the N-type field effect transistor, and a source of the N-type field effect transistor outputs the control signal.
8. the LED differential pressure protection circuit of claim 7, wherein the control circuit further comprises a voltage dropping resistor, one end of the voltage dropping resistor is connected with the output end of the comparison circuit, and the other end of the voltage dropping resistor is connected with the grid electrode of the N-type field effect transistor.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112859991A (en) * | 2021-04-23 | 2021-05-28 | 深圳市拓尔微电子有限责任公司 | Voltage processing circuit and method of controlling voltage processing circuit |
| CN115460734A (en) * | 2022-05-17 | 2022-12-09 | 深圳锐盟半导体有限公司 | LED control circuit, electronic equipment and electronic device |
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2019
- 2019-04-28 CN CN201920593629.XU patent/CN209747106U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112859991A (en) * | 2021-04-23 | 2021-05-28 | 深圳市拓尔微电子有限责任公司 | Voltage processing circuit and method of controlling voltage processing circuit |
| CN115460734A (en) * | 2022-05-17 | 2022-12-09 | 深圳锐盟半导体有限公司 | LED control circuit, electronic equipment and electronic device |
| CN115460734B (en) * | 2022-05-17 | 2023-12-01 | 深圳锐盟半导体有限公司 | LED control circuit, electronic equipment and electronic device |
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