CN110139434B - Driving circuit and driving method - Google Patents
Driving circuit and driving method Download PDFInfo
- Publication number
- CN110139434B CN110139434B CN201910433015.XA CN201910433015A CN110139434B CN 110139434 B CN110139434 B CN 110139434B CN 201910433015 A CN201910433015 A CN 201910433015A CN 110139434 B CN110139434 B CN 110139434B
- Authority
- CN
- China
- Prior art keywords
- current
- driving
- bias
- mos tube
- module
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
Landscapes
- Amplifiers (AREA)
- Led Devices (AREA)
Abstract
The embodiment of the invention provides a driving circuit and a driving method.A current bias module generates a first bias current and generates a second bias current by combining the first bias current and a feedback current output by an operational amplifier. The current bias module outputs a second bias current to the negative input end of the operational amplifier and outputs a first bias current to the driving module. The driving module generates driving current and outputs the driving current to the LED and the positive input end of the operational amplifier respectively. The operational amplifier carries out current negative feedback operation according to the driving current and the second bias current to obtain feedback current, and outputs the feedback current to the current bias module to enable the ratio of the second bias current to the driving current to be within a preset range. In the scheme, the second bias current and the driving current are respectively used as the input of the operational amplifier to carry out current negative feedback control, so that the ratio of the second bias current to the driving current is in a preset range, and the high-precision driving current is provided.
Description
Technical Field
The invention relates to the technical field of electronics, in particular to a driving circuit and a driving method.
Background
With the development of society, more and more mobile phones are using Red Green Blue (RGB) light effect and Face ID in order to make the mobile phones become diversified. In the mobile phone, both RGB lamp effect and faceID are controlled by an LED driving circuit. In the LED driving circuit, a plurality of P-type MOS transistors constitute a mirror current source, in which the MOS transistor connected in a diode form is used as a mirror source, the output current is I1, and the other MOS transistors are mirror transistors, the magnitude of the output current is proportional to the magnitude of the current I1, and the magnitude of the output current of the other MOS transistors, that is, the magnitude of the current of the LED lamp is generally controlled by controlling the magnitude of the current I1.
However, the application environment of the LED driving circuit is more and more complex, and the requirement for the current accuracy of the LED is more and more high, and when the LED driving circuit in the prior art is under a large current, the variation range of the forward voltage and the cathode voltage of the LED can reach several volts, which causes the channel length modulation effect to be generated, so that the mirror current generates a deviation, and therefore, the LED driving circuit in the prior art cannot accurately control the current of the LED.
Disclosure of Invention
In view of this, embodiments of the present invention provide a driving circuit and a driving method to solve the problem that the LED driving circuit in the prior art cannot accurately control the magnitude of the LED current.
In order to achieve the above purpose, the embodiments of the present invention provide the following technical solutions:
the first aspect of the embodiments of the present invention discloses a driving circuit, which is suitable for an LED, and the driving circuit includes: the current bias module, the operational amplifier and the driving module;
the current bias module is used for generating a first bias current, combining the first bias current and the feedback current output by the operational amplifier to generate a second bias current, outputting the second bias current to the negative electrode input end of the operational amplifier, and outputting the first bias current to the driving module;
the driving module is connected with the current bias module and is used for driving current and outputting the driving current to the LED and the positive input end of the operational amplifier respectively;
the operational amplifier is used for performing current negative feedback operation according to the driving current and the second bias current to obtain the feedback current, and outputting the feedback current to the current bias module to enable the ratio of the second bias current to the driving current to be within a preset range.
Preferably, the current bias module includes: the MOS transistor comprises a first MOS transistor, a second MOS transistor, a third MOS transistor, a fourth MOS transistor and a current source;
the current source is used for generating the first bias current, one end of the current source is respectively connected with the first end of the driving module, the grid electrode of the third MOS tube and the drain electrode of the fourth MOS tube, and the other end of the current source is grounded;
the grid electrode and the drain electrode of the first MOS tube are respectively connected with the drain electrode of the second MOS tube, the grid electrode of the first MOS tube is connected with the grid electrode of the fourth MOS tube, and the source electrode of the first MOS tube is connected with the second end of the driving module;
the source electrode of the second MOS tube is grounded, and the grid electrode of the second MOS tube is connected with the output end of the operational amplifier and receives the feedback current;
the source electrode of the third MOS tube is connected with the second end of the driving module, the drain electrode of the third MOS tube is connected with the negative electrode input end of the operational amplifier, and the second bias current is output to the operational amplifier;
and the source electrode of the fourth MOS tube is connected with the second end of the driving module.
Preferably, the driving module includes: n MOS tubes, wherein N is a positive integer;
for each MOS tube of the driving module, the source electrode of the MOS tube is connected with the first end of the current bias module, the grid electrode of the MOS tube is connected with the second end of the current bias module, the drain electrode of the MOS tube is respectively connected with the LED and the positive input end of the operational amplifier, and the driving current is output to the operational amplifier and the LED.
Preferably, the operational amplifier includes: a fifth MOS tube, a sixth MOS tube, a seventh MOS tube and an eighth MOS tube;
the source electrode of the fifth MOS tube is grounded, the grid electrode of the fifth MOS tube is respectively connected with the grid electrode of the second MOS tube and the grid electrode of the sixth MOS tube, and the drain electrode and the grid electrode of the fifth MOS tube are respectively connected with the drain electrode of the eighth MOS tube;
the source electrode of the sixth MOS tube is grounded, and the drain electrode of the sixth MOS tube is respectively connected with the grid electrode and the drain electrode of the seventh MOS tube;
the grid electrode of the seventh MOS tube is connected with the grid electrode of the eighth MOS tube, and the source electrode of the seventh MOS tube is connected with the drain electrode of each MOS tube in the driving module;
and the source electrode of the eighth MOS tube is connected with the drain electrode of the third MOS tube.
A second aspect of the present invention discloses a driving method applied to the driving circuit disclosed in the first aspect of the present invention, where the driving method includes:
the current bias module generates a first bias current and generates a second bias current by combining the first bias current and a feedback current output by the operational amplifier;
the current bias module outputs the second bias current to a negative input end of the operational amplifier and outputs the first bias current to a driving module;
the driving module generates driving current and outputs the driving current to the LED and the positive input end of the operational amplifier respectively;
and the operational amplifier carries out current negative feedback operation according to the driving current and the second bias current to obtain the feedback current, and outputs the feedback current to the current bias module to enable the ratio of the second bias current to the driving current to be within a preset range.
Based on the driving circuit and the driving method provided by the embodiment of the invention, the driving circuit comprises: the device comprises a current bias module, an operational amplifier and a driving module. The current bias module generates a first bias current and combines the first bias current and a feedback current output by the operational amplifier to generate a second bias current. The current bias module outputs a second bias current to the negative input end of the operational amplifier and outputs a first bias current to the driving module. The driving module generates driving current and outputs the driving current to the LED and the positive input end of the operational amplifier respectively. The operational amplifier carries out current negative feedback operation according to the driving current and the second bias current to obtain feedback current, and outputs the feedback current to the current bias module to enable the ratio of the second bias current to the driving current to be within a preset range. In the scheme, the second bias current of the current bias module and the drive current of the drive module are respectively used as the input of the operational amplifier to carry out current negative feedback control, so that the ratio of the second bias current to the drive current is in a preset range, the error caused by the channel length modulation effect of the drive circuit is eliminated, and the high-precision drive current can be provided.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a driving circuit according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a driving circuit according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of another driving circuit according to an embodiment of the present invention;
fig. 4 is a flowchart of a driving method according to an embodiment of the present invention.
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 derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In this application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
It can be known from the background art that, because the application environment of the LED driving circuit is more and more complex, the requirement for the current precision of the LED is more and more high, and the variation range of the forward voltage and the cathode voltage of the LED can reach several volts under a larger current in the LED driving circuit in the prior art, which results in the generation of the channel length modulation effect, so that the mirror current generates deviation, and therefore, the LED driving circuit in the prior art can not accurately control the current of the LED.
Therefore, embodiments of the present invention provide a driving circuit and a driving method, in which a second bias current of a current bias module and a driving current of a driving module are respectively used as inputs of an operational amplifier to perform current negative feedback control, so that a ratio of the second bias current to the driving current is within a preset range, thereby eliminating an error caused by a channel length modulation effect of the driving circuit and improving control accuracy of an LED current.
Referring to fig. 1, a schematic structural diagram of a driving circuit provided in an embodiment of the present invention is shown, where the driving circuit includes: a current bias module 100, a driving module 200 and an operational amplifier 300.
The current bias module 100 is configured to generate a first bias current, combine the first bias current and a feedback current output by the operational amplifier 300 to generate a second bias current, output the second bias current to a negative input terminal of the operational amplifier 300, and output the first bias current to the driving module 200.
The driving module 200 is connected to the current bias module 100, and the driving module 200 is configured to generate a driving current and output the driving current to the LED and the positive input end of the operational amplifier 300, respectively.
In a specific implementation, the driving current output to the LED by the driving module 200 is used for driving the LED.
The operational amplifier 300 is configured to perform a current negative feedback operation according to the driving current and the second bias current to obtain the feedback current, and output the feedback current to the current bias module 100, so that a ratio of the second bias current to the driving current is within a preset range.
In a specific implementation, the second bias current is used as an input signal of a negative input end of the operational amplifier 300, the driving current is used as an input signal of a positive input end of the operational amplifier 300, a current negative feedback operation is performed based on a preset control strategy to obtain the feedback current, and the feedback current is fed back to the current bias module 100 to form a complete current negative feedback system, so that a ratio of the second bias current to the driving current is within a preset range.
In the embodiment of the invention, the current bias module generates a first bias current and combines the first bias current and the feedback current output by the operational amplifier to generate a second bias current. The current bias module outputs a second bias current to the negative input end of the operational amplifier and outputs a first bias current to the driving module. The driving module generates driving current and outputs the driving current to the LED and the positive input end of the operational amplifier respectively. The operational amplifier carries out current negative feedback operation according to the driving current and the second bias current to obtain feedback current, the feedback current is output to the current bias module, the ratio of the second bias current to the driving current is enabled to be within a preset range, errors caused by the channel length modulation effect of the driving circuit are eliminated, and high-precision driving current can be provided.
Preferably, to better explain the specific structures of the current bias module 100 and the driving module 200 referred to in fig. 1 of the above embodiment of the present invention, referring to fig. 2, a schematic diagram of an architecture of a driving circuit provided in the embodiment of the present invention is shown. The driving circuit in fig. 2 is a current parallel negative feedback circuit.
The specific structure of the current bias module 100 shown in the embodiment of the present invention includes: the MOS transistor comprises a first MOS transistor, a second MOS transistor, a third MOS transistor, a fourth MOS transistor and a current source.
The current source is configured to generate the first bias current, one end of the current source is connected to the first end of the driving module 200, the gate of the third MOS transistor, and the drain of the fourth MOS transistor, respectively, and the other end of the current source is grounded.
In a specific implementation, one end of the current source is connected to the gate of each MOS transistor in the driving module 200.
The grid electrode and the drain electrode of the first MOS tube are respectively connected with the drain electrode of the second MOS tube, the grid electrode of the first MOS tube is connected with the grid electrode of the fourth MOS tube, and the source electrode of the first MOS tube is connected with the second end of the driving module 200.
In a specific implementation, the source of the first MOS transistor is connected to the source of each MOS transistor in the driving module 200.
The source of the second MOS transistor is grounded, and the gate of the second MOS transistor is connected to the output terminal of the operational amplifier 300, and receives the feedback current.
The source of the third MOS transistor is connected to the second end of the driving module 200, and the drain of the third MOS transistor is connected to the negative input end of the operational amplifier 300, so as to output the second bias current to the operational amplifier 300.
In a specific implementation, the source of the third MOS transistor is connected to the source of each MOS transistor in the driving module 200.
The source of the fourth MOS transistor is connected to the second end of the driving module 200.
In a specific implementation, the source of the fourth MOS transistor is connected to the source of each MOS transistor in the driving module 200.
It should be noted that, in the specific structure of the current bias module 100 according to the embodiment of the present invention, the symbol meanings in fig. 2 are respectively: m1 represents the first MOS transistor, M2 represents the second MOS transistor, M3 represents the third MOS transistor, M4 represents the fourth MOS transistor, IREF represents the first bias current generated by the current source, and I3Representing the second bias current.
The specific structure of the driving module 200 shown in the embodiment of the present invention includes: n MOS pipes, N is a positive integer.
For each MOS transistor of the driving module 200, a source of the MOS transistor is connected to the first end of the current bias module 100, a gate of the MOS transistor is connected to the second end of the current bias module 100, and a drain of the MOS transistor is connected to the LED and the positive input end of the operational amplifier 300, respectively, so as to output the driving current to the operational amplifier 300 and the LED.
In a specific implementation, the sources of the MOS transistors are respectively connected to the sources of the first MOS transistor, the third MOS transistor and the fourth MOS transistor in the current bias module 100. The gate of the MOS transistor is connected to the current source in the current bias module 100.
It should be noted that, for the specific structure of the driving module 200 according to the embodiment of the present invention, the symbol meanings in fig. 2 are respectively: P0-PN respectively represent N MOS transistors, I of the driving module 2004For the driving current, LED _ PAD is an LED connected to the driving module 200.
It should be noted that, in the specific structures of the current bias module 100 and the driving module 200 respectively shown in fig. 2 in the above embodiment of the present invention, the first MOS transistor is in a mirror relationship with the third MOS transistor and the fourth MOS transistor respectively. I.e. the current I shown in said fig. 21And I2Proportional relation, and current I1And I3In a proportional relationship. Similarly, the third MOS transistor in fig. 2 is in a mirror relationship with the MOS transistor in the driving module 200, and the current I3And I4In a proportional relationship.
Further, the types of MOS transistors in the current bias module 100 and the driving module 200 are NMOS transistors or PMOS transistors, the current source in the current bias module 100 is any high-impedance current source, the operational amplifier 300 is any high-gain current comparator or operational amplifier, the specific type is selected by a technician according to actual requirements, and is not specifically limited in the embodiment of the present invention.
In order to better explain how the above-mentioned driving circuit eliminates the error caused by the channel length modulation effect of the MOS transistor, so as to provide an accurate driving current, the qualitative analysis of the driving circuit in fig. 2 is performed in conjunction with the schematic architecture diagram of the driving circuit shown in fig. 2, and the specific analysis content is described in detail as follows.
The drive circuit in FIG. 2 regulates I through a current negative feedback loop4As can be seen from the above, the third MOS transistor is in a mirror image relationship with the MOS transistor in the driving module 200, and the current flows through the third MOS transistorI3And I4In a proportional relationship. So when I4At the time of descent, I3And the gate-source voltage of the second MOS tube is reduced at the same time, so that I is caused1And (4) descending. From the above, the current I1And I2Proportional relationship, therefore I1Decrease leads to I2And (4) descending. Since the first bias current IREF generated by the current source is not changed, the potential at the point F in FIG. 2 is lowered, the gate-source voltage of the third MOS transistor is raised, and I3Rises therewith, I4And also rises. From the above qualitative analysis, when the voltage of the LED _ PAD connected to the driving circuit is floated, the operational amplifier 300 can control the potential at the point a in fig. 2 to follow the voltage change of the LED _ PAD, so as to eliminate the error caused by the channel length modulation effect.
In the case of performing qualitative analysis, the above-mentioned case is I4Decrease when said I4When rising, the driving circuit pair I4The adjustment principle of (2) can be referred to the content of the above qualitative analysis, and is not described herein again.
In the embodiment of the invention, the second bias current of the current bias module and the drive current of the drive module are respectively used as the input of the operational amplifier, and the feedback current is fed back to the current bias module after current negative feedback operation is carried out, so that the current parallel negative feedback circuit is formed. Through the current parallel negative feedback circuit, the ratio of the second bias current to the driving current is in a preset range, errors caused by the channel length modulation effect of the driving circuit are eliminated, and high-precision driving current can be provided.
To better explain the specific structure of the operational amplifier 300 referred to in fig. 1 and fig. 2, referring to fig. 3 in conjunction with fig. 2, another architecture diagram of a driving circuit provided in the embodiment of the present invention is shown, in fig. 3, the operational amplifier 300 includes: the fifth MOS tube, the sixth MOS tube, the seventh MOS tube and the eighth MOS tube.
The source electrode of the fifth MOS tube is grounded, the grid electrode of the fifth MOS tube is respectively connected with the grid electrode of the second MOS tube and the grid electrode of the sixth MOS tube, and the drain electrode and the grid electrode of the fifth MOS tube are respectively connected with the drain electrode of the eighth MOS tube.
And the source electrode of the sixth MOS tube is grounded, and the drain electrode of the sixth MOS tube is respectively connected with the grid electrode and the drain electrode of the seventh MOS tube.
The grid electrode of the seventh MOS tube is connected with the grid electrode of the eighth MOS tube, and the source electrode of the seventh MOS tube is connected with the drain electrode of each MOS tube in the driving module.
And the source electrode of the eighth MOS tube is connected with the drain electrode of the third MOS tube.
It should be noted that, in the specific structure of the operational amplifier 300 according to the embodiment of the present invention, the symbol meanings in fig. 3 are respectively: m5 denotes a fifth MOS transistor, M6 denotes a sixth MOS transistor, M7 denotes a seventh MOS transistor, and M8 denotes an eighth MOS transistor.
Further, it should be noted that the type of the MOS transistor in the operational amplifier 300 is an NMOS transistor or a PMOS transistor, and the specific type is selected by a skilled person according to actual requirements, and the specific structure of the operational amplifier 300 includes, but is not limited to, the structure shown in fig. 3, and is not specifically limited in the embodiment of the present invention.
In order to better explain how the driving circuit according to the embodiment of the present invention provides high-precision driving current, the driving circuit in fig. 3 is quantitatively analyzed in conjunction with the contents in fig. 2 and fig. 3, and the detailed analysis process is described in the following.
The drive circuit in FIG. 3 is broken virtually and inserted with the test signal VtThe output signal of the driving circuit is VF，VtAnd VFThe concrete content is as formula (1), in said formula (1), gm1、gm2、gm3、gm4And gm5Transconductance R of the first MOS transistor, the second MOS transistor, the third MOS transistor, the fourth MOS transistor and the fifth MOS transistor respectivelyIREFIs the impedance of the current source.
As can be seen from the above description of FIG. 2, the current I1And I2Proportional relation, and current I1And I3In a proportional relationship. Assuming a current I1And I2Has a ratio of 1, current I1And I3Is 1, i.e. gm1And gm4Equal to, gm2And gm5Are equal. And calculating the loop gain of the driving circuit according to the formula (2) by combining the formula (1). In the formula (2), AIAnd beta is the feedback coefficient of the driving circuit.
βAI＝gm4RIREF (2)
Calculating the closed loop gain A of the drive circuit by combining the loop gain calculated in the formula (2)CLAs in equation (3).
As can be seen from the above formula (3), when A isIWhen sufficiently large, the closed loop gain A of the drive circuitCLIs equal to
Therefore, g is adjusted by adjusting the size of the fourth MOS tubem4RIREFSufficiently large, e.g. up to 103Is such that the feedback coefficient beta of the drive circuit is equal to 1, thereby resulting in a closed loop gain a of the drive circuitCLMaintained at [0.999, 1]]And in the interval, high-precision driving current is provided for the LED.
In the embodiment of the invention, the second bias current of the current bias module and the drive current of the drive module are respectively used as the input of the operational amplifier, and the feedback current is fed back to the current bias module after current negative feedback operation is carried out, so that the current parallel negative feedback circuit is formed. The current is connected with the negative feedback circuit in parallel, so that the closed loop gain of the driving circuit is kept in a value range of [0.999, 1], errors caused by the channel length modulation effect of the driving circuit are eliminated, and high-precision driving current can be provided.
Corresponding to the driving circuit shown in the above embodiment of the present invention, referring to fig. 4, an embodiment of the present invention further provides a flowchart of a driving method, where the driving method is applied to the driving circuit, and the driving method includes:
step S401: the current bias module generates a first bias current and combines the first bias current and a feedback current output by the operational amplifier to generate a second bias current.
Step S402: the current bias module outputs the second bias current to a negative input end of the operational amplifier and outputs the first bias current to a driving module.
Step S403: the driving module generates driving current and outputs the driving current to the LED and the anode input end of the operational amplifier respectively.
Step S404: and the operational amplifier carries out current negative feedback operation according to the driving current and the second bias current to obtain the feedback current, and outputs the feedback current to the current bias module to enable the ratio of the second bias current to the driving current to be within a preset range.
It should be noted that, for the execution principle of the above steps S401 to S404, specific reference is made to the contents shown in fig. 1 to fig. 3 in the above embodiment of the present invention, and details are not repeated in the embodiment of the present invention.
In the embodiment of the invention, the current bias module generates a first bias current and combines the first bias current and the feedback current output by the operational amplifier to generate a second bias current. The current bias module outputs a second bias current to the negative input end of the operational amplifier and outputs a first bias current to the driving module. The driving module generates driving current and outputs the driving current to the LED and the positive input end of the operational amplifier respectively. The operational amplifier carries out current negative feedback operation according to the driving current and the second bias current to obtain feedback current, the feedback current is output to the current bias module, the ratio of the second bias current to the driving current is enabled to be within a preset range, errors caused by the channel length modulation effect of the driving circuit are eliminated, and high-precision driving current can be provided.
In summary, the embodiments of the present invention provide a driving circuit and a driving method, the driving circuit includes: the device comprises a current bias module, an operational amplifier and a driving module. The current bias module generates a first bias current and combines the first bias current and a feedback current output by the operational amplifier to generate a second bias current. The current bias module outputs a second bias current to the negative input end of the operational amplifier and outputs a first bias current to the driving module. The driving module generates driving current and outputs the driving current to the LED and the positive input end of the operational amplifier respectively. The operational amplifier carries out current negative feedback operation according to the driving current and the second bias current to obtain feedback current, and outputs the feedback current to the current bias module to enable the ratio of the second bias current to the driving current to be within a preset range. In the scheme, the second bias current of the current bias module and the drive current of the drive module are respectively used as the input of the operational amplifier to carry out current negative feedback control, so that the ratio of the second bias current to the drive current is in a preset range, the error caused by the channel length modulation effect of the drive circuit is eliminated, and the high-precision drive current can be provided.
The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, the system or system embodiments are substantially similar to the method embodiments and therefore are described in a relatively simple manner, and reference may be made to some of the descriptions of the method embodiments for related points. The above-described system and system embodiments are only illustrative, wherein the units described as separate parts may or may not be physically separate, and the parts displayed 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 modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. 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 invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (4)
1. A driver circuit adapted for use with an LED, the driver circuit comprising: the current bias module, the operational amplifier and the driving module; the current bias module includes: the MOS transistor comprises a first MOS transistor, a second MOS transistor, a third MOS transistor, a fourth MOS transistor and a current source;
the current bias module is used for generating a first bias current, combining the first bias current and the feedback current output by the operational amplifier to generate a second bias current, outputting the second bias current to the negative electrode input end of the operational amplifier, and outputting the first bias current to the driving module;
the driving module is connected with the current bias module and used for generating driving current and outputting the driving current to the LED and the positive input end of the operational amplifier respectively;
the operational amplifier is used for performing current negative feedback operation according to the driving current and a second bias current to obtain the feedback current, and outputting the feedback current to the current bias module to enable the ratio of the second bias current to the driving current to be within a preset range;
the current source is used for generating the first bias current, one end of the current source is respectively connected with the first end of the driving module, the grid electrode of the third MOS tube and the drain electrode of the fourth MOS tube, and the other end of the current source is grounded;
the grid electrode and the drain electrode of the first MOS tube are respectively connected with the drain electrode of the second MOS tube, the grid electrode of the first MOS tube is connected with the grid electrode of the fourth MOS tube, and the source electrode of the first MOS tube is connected with the second end of the driving module;
the source electrode of the second MOS tube is grounded, and the grid electrode of the second MOS tube is connected with the output end of the operational amplifier and receives the feedback current;
the source electrode of the third MOS tube is connected with the second end of the driving module, the drain electrode of the third MOS tube is connected with the negative electrode input end of the operational amplifier, and the second bias current is output to the operational amplifier;
and the source electrode of the fourth MOS tube is connected with the second end of the driving module.
2. The driving circuit according to claim 1, wherein the driving module comprises: n MOS tubes, wherein N is a positive integer;
for each MOS tube of the driving module, the source electrode of the MOS tube is connected with the first end of the current bias module, the grid electrode of the MOS tube is connected with the second end of the current bias module, the drain electrode of the MOS tube is respectively connected with the LED and the positive input end of the operational amplifier, and the driving current is output to the operational amplifier and the LED.
3. The driving circuit according to claim 1, wherein the operational amplifier comprises: a fifth MOS tube, a sixth MOS tube, a seventh MOS tube and an eighth MOS tube;
the source electrode of the fifth MOS tube is grounded, the grid electrode of the fifth MOS tube is respectively connected with the grid electrode of the second MOS tube and the grid electrode of the sixth MOS tube, and the drain electrode and the grid electrode of the fifth MOS tube are respectively connected with the drain electrode of the eighth MOS tube;
the source electrode of the sixth MOS tube is grounded, and the drain electrode of the sixth MOS tube is respectively connected with the grid electrode and the drain electrode of the seventh MOS tube;
the grid electrode of the seventh MOS tube is connected with the grid electrode of the eighth MOS tube, and the source electrode of the seventh MOS tube is connected with the drain electrode of each MOS tube in the driving module;
and the source electrode of the eighth MOS tube is connected with the drain electrode of the third MOS tube.
4. A driving method applied to the driving circuit according to any one of claims 1 to 3, the driving method comprising:
the current bias module generates a first bias current and generates a second bias current by combining the first bias current and a feedback current output by the operational amplifier;
the current bias module outputs the second bias current to a negative input end of the operational amplifier and outputs the first bias current to a driving module;
the driving module generates driving current and outputs the driving current to the LED and the positive input end of the operational amplifier respectively;
and the operational amplifier carries out current negative feedback operation according to the driving current and the second bias current to obtain the feedback current, and outputs the feedback current to the current bias module to enable the ratio of the second bias current to the driving current to be within a preset range.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910433015.XA CN110139434B (en) | 2019-05-23 | 2019-05-23 | Driving circuit and driving method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910433015.XA CN110139434B (en) | 2019-05-23 | 2019-05-23 | Driving circuit and driving method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110139434A CN110139434A (en) | 2019-08-16 |
| CN110139434B true CN110139434B (en) | 2021-08-27 |
Family
ID=67572628
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910433015.XA Active CN110139434B (en) | 2019-05-23 | 2019-05-23 | Driving circuit and driving method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110139434B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1811657A (en) * | 2006-01-16 | 2006-08-02 | 启攀微电子（上海）有限公司 | Electric current source circuit for driving large current load |
| CN101409967A (en) * | 2008-11-03 | 2009-04-15 | 深圳市联德合微电子有限公司 | Multipath LED drive circuit |
| US7781983B1 (en) * | 2007-07-20 | 2010-08-24 | Vimicro Corporation | Closed-loop feedback circuit for controlling LEDs |
| CN102843807A (en) * | 2011-06-21 | 2012-12-26 | 原景科技股份有限公司 | LED circuit with LED drive circuit |
| CN108848594A (en) * | 2018-07-11 | 2018-11-20 | 上海艾为电子技术股份有限公司 | A kind of LED drive circuit and LED multi-path luminescent system |
-
2019
- 2019-05-23 CN CN201910433015.XA patent/CN110139434B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1811657A (en) * | 2006-01-16 | 2006-08-02 | 启攀微电子（上海）有限公司 | Electric current source circuit for driving large current load |
| US7781983B1 (en) * | 2007-07-20 | 2010-08-24 | Vimicro Corporation | Closed-loop feedback circuit for controlling LEDs |
| CN101409967A (en) * | 2008-11-03 | 2009-04-15 | 深圳市联德合微电子有限公司 | Multipath LED drive circuit |
| CN102843807A (en) * | 2011-06-21 | 2012-12-26 | 原景科技股份有限公司 | LED circuit with LED drive circuit |
| CN108848594A (en) * | 2018-07-11 | 2018-11-20 | 上海艾为电子技术股份有限公司 | A kind of LED drive circuit and LED multi-path luminescent system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110139434A (en) | 2019-08-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104820456B (en) | Current source calibration tracks temperature and bias current | |
| US20170126329A1 (en) | Wideband low dropout voltage regulator with power supply rejection boost | |
| CN107727925B (en) | High-precision wide-range peak current sampling circuit | |
| CN110767152B (en) | Constant current source generating method of LED display screen driving chip | |
| CN108073215A (en) | The reference voltage circuit of temperature-compensating | |
| CN107562111B (en) | DC stabilized power supply and voltage regulation method | |
| CN110708809B (en) | Constant current source generating circuit of common-anode LED display screen driving chip | |
| WO2020103725A1 (en) | Differential input circuit, amplification circuit, and display apparatus | |
| US12079020B2 (en) | Constant current source calibration circuit, constant current source drive circuit, drive chip, and electronic device | |
| US9568929B2 (en) | Bandgap reference circuit with beta-compensation | |
| JP2011166724A (en) | Current driving circuit, and light-emitting apparatus employing the same | |
| CN116009641A (en) | Current mirror circuit, protection circuit, bias circuit and electronic equipment | |
| CN110139434B (en) | Driving circuit and driving method | |
| CN111026230A (en) | LDO device and storage equipment | |
| US9523995B2 (en) | Reference voltage circuit | |
| US7075281B1 (en) | Precision PTAT current source using only one external resistor | |
| CN116865740B (en) | Analog multiplier circuit | |
| WO2022228407A1 (en) | Solid-state direct-current voltage reference circuit | |
| CN113434005B (en) | Controllable resistance circuit | |
| US20220253086A1 (en) | Current mirror circuit | |
| CN116520930A (en) | Low-dropout linear voltage stabilizing circuit, trimming control method, chip and electronic equipment | |
| CN108345336B (en) | Energy gap reference circuit | |
| JP2545501B2 (en) | DC signal conversion circuit | |
| US20180308423A1 (en) | Conversion Circuit and Operation Method Thereof, Compensation Device, and Display Apparatus | |
| CN114690843A (en) | MOS pipe temperature sensor circuit of low-power consumption |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |