CN108055730B - Constant-current switching power supply control circuit, chip and LED driving circuit - Google Patents
Constant-current switching power supply control circuit, chip and LED driving circuit Download PDFInfo
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- CN108055730B CN108055730B CN201711456875.2A CN201711456875A CN108055730B CN 108055730 B CN108055730 B CN 108055730B CN 201711456875 A CN201711456875 A CN 201711456875A CN 108055730 B CN108055730 B CN 108055730B
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- 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]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
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- 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]
- H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
Abstract
The invention belongs to the technical field of power electronics, and provides a three-terminal constant-current switching power supply control circuit, a control chip and an LED driving circuit. The three-terminal constant current switching power supply control circuit comprises: the device comprises a reference source, a first sampling circuit, a second sampling circuit, a time-sharing control driving module, a valley detection module, a power switch module and a power supply control module; the reference source is connected between the charging end and the grounding end and generates reference voltage; the first sampling circuit samples the difference between the reference voltage and the voltage of the grounding end according to a first control driving signal to obtain a first sampling signal; the second sampling circuit samples the difference between the voltage of the charging end and the reference voltage according to a second control driving signal to obtain a second sampling signal; the time-sharing control driving module can control the power switch module to output a direct-current voltage signal according to the corresponding sampling signal; the invention solves the problems of higher design cost and larger random error of the circuit in the prior art.
Description
Technical Field
The invention belongs to the technical field of power electronics, and particularly relates to a three-terminal constant-current switching power supply control circuit, a control chip and an LED driving circuit.
Background
In the prior art, a constant current switching power supply control circuit can convert periodic current input from the outside into constant power supply with stable output; in the constant-current switching power supply control circuit, corresponding electric energy is stored in the charging process through the energy storage element, and when the power switching tube is disconnected or turned off, the energy storage element outputs the electric energy, and the voltage stabilizing circuit can always keep the stability of the output voltage of the control circuit in the charging and discharging process of the storage element, so that the constant-current switching power supply is always in a stable running state.
Then, the prior art has at least the following problems: because independent junction field effect transistors are needed for power supply, a plurality of junction field effect transistors are arranged in the constant current switching power supply control circuit, so that the control circuit is complex in structure and high in design cost; meanwhile, the consistency in the control circuit can only reach +/-5%, and larger random errors exist in the constant-current switching power supply control circuit.
Disclosure of Invention
The invention provides a three-terminal constant current switching power supply control circuit, a control chip and an LED driving circuit, and aims to solve the problems of higher design cost and larger random error of the three-terminal constant current switching power supply control circuit in the prior art.
The first aspect of the present invention provides a three-terminal constant current switching power supply control circuit, comprising:
the reference source is connected between the charging end and the grounding end and is used for generating reference voltage according to a power supply signal or a charging signal;
the first sampling circuit is connected with the reference source and is used for sampling the difference between the reference voltage and the voltage of the grounding end according to a first control driving signal to obtain a first sampling signal;
the second sampling circuit is connected with the reference source and is used for sampling the difference between the voltage of the charging end and the reference voltage according to a second control driving signal to obtain a second sampling signal;
the time-sharing control driving module is connected with the first sampling circuit and the second sampling circuit and is used for generating the first control driving signal, the second control driving signal and the turn-off signal according to the first sampling signal and the second sampling signal and generating a turn-on signal when a valley signal is detected within a preset time threshold value or the preset time threshold value is exceeded;
the power switch module is connected between the power end and the grounding end and is used for outputting a direct-current voltage signal under the drive of the turn-off signal;
the valley detection module is connected with the time-sharing control driving module and used for generating the valley signal when detecting the demagnetizing resonance voltage signal of the power switch module; a kind of electronic device with high-pressure air-conditioning system
And the power supply control module is connected between the reference source and the power switch module and is used for generating the power supply signal according to the direct-current voltage signal.
Further, the first sampling circuit includes: a first switch, a first comparator, and a first capacitor;
the first switch is connected between the reference source and the non-inverting input end of the first comparator, the first capacitor is connected between the charging end and the non-inverting input end of the first comparator, the inverting input end of the first comparator is connected with the grounding end, and the output end of the first comparator outputs the first sampling signal.
Further, the second sampling circuit includes: a second switch, a second capacitor and a second comparator;
the second switch is connected between the reference source and the non-inverting input end of the second comparator, the second capacitor is connected between the non-inverting input end of the second comparator and the grounding end, the inverting input end of the second comparator is connected with the charging end, and the output end of the second comparator outputs the second sampling signal.
Further, the power switch module comprises a power switch tube;
the G end of the power switch tube is connected with the time-sharing control driving module, the D end of the power switch tube is connected with the power supply end, the S end of the power switch tube is connected with the grounding end, and the JS end of the power switch tube outputs the direct-current voltage signal.
The second aspect of the invention provides a three-terminal constant current switching power supply control chip, which comprises the three-terminal constant current switching power supply control circuit;
the charging pin is connected with the charging end of the three-terminal constant-current switching power supply control circuit and used for being connected with the charging signal;
the power supply pin is connected with the power supply end of the three-terminal constant-current switching power supply control circuit and used for being connected with a direct-current power supply; and
and a ground pin connected with the ground end of the three-terminal constant current switching power supply control circuit.
A third aspect of the present invention provides an LED driving circuit for driving an LED array, the LED array including at least one LED lamp bead, comprising:
the three-terminal constant current switching power supply control chip is as described above;
the rectification filter module is used for outputting the direct current power supply;
the energy storage circuit is connected between the first end of the rectifying and filtering module and the power pin of the three-terminal constant-current switching power supply control chip and used for storing electric energy, and the LED array is connected with the energy storage circuit in parallel;
the charging circuit is connected between the charging pin of the three-terminal constant-current switching power supply control chip and the second end of the rectifying and filtering module and is used for generating the charging signal; and
and the sampling resistor is connected between the ground pin of the three-terminal constant current switching power supply control chip and the second end of the rectifying and filtering module.
Further, the rectifying and filtering module comprises a first diode, a second diode, a third diode, a fourth diode and a third capacitor;
wherein the anode of the first diode, the anode of the second diode, the cathode of the third diode and the cathode of the fourth diode are used for connecting an alternating current power supply;
the cathode of the first diode, the cathode of the second diode and the first end of the third capacitor are the first ends of the rectifying and filtering module, and the anode of the third diode, the anode of the fourth diode and the second end of the third capacitor are the second ends of the rectifying and filtering module.
Further, a third switch is also included;
the third switch is connected between the anode of the first diode and the cathode of the third diode and the alternating current power supply.
Further, the tank circuit includes: a filter capacitor, an inductor and a flywheel diode;
the first end of the filter capacitor and the cathode of the freewheeling diode are connected with the first end of the rectifying and filtering module, the second end of the filter capacitor is connected with the first end of the inductor, and the second end of the inductor and the anode of the freewheeling diode are connected with the power pin of the three-terminal constant-current switching power supply control chip.
Further, the charging circuit comprises a power supply capacitor;
and the power supply capacitor is connected between a charging pin of the three-terminal constant-current switching power supply control chip and the second end of the rectifying and filtering module.
The invention has the following beneficial technical effects to the prior art: in the three-terminal constant current switching power supply control circuit, the difference between the reference voltage and the voltage of the grounding end is sampled through the first sampling circuit, and the voltage of the charging end and the reference voltage are sampled through the second sampling circuit, and as the mismatch design of the two sampling circuits has the mutual offset effect, the consistency of the constant current switching power supply control circuit can be reduced to less than +/-3 percent, and random errors are reduced; the integrated power switch module is introduced to output corresponding direct-current voltage signals and provide corresponding direct-current power supplies, so that the structure of the control circuit is simplified, and the industrial cost is reduced; the three-terminal constant current switching power supply control circuit effectively solves the problems of high design cost and large random error of a three-terminal constant current switching power supply control circuit in the prior art.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a circuit configuration diagram of a three-terminal constant current switching power supply control circuit provided by an embodiment of the present invention;
fig. 2 is a circuit structure diagram of a three-terminal constant current switching power supply control chip provided by an embodiment of the invention;
fig. 3 is a circuit configuration diagram of an LED driving circuit according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of an LED lamp according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Fig. 1 shows a circuit structure diagram of a three-terminal constant current switching power supply control circuit provided by an embodiment of the present invention, and for convenience of explanation, only parts related to the embodiment of the present invention are shown, and the details are as follows:
as shown in fig. 1, the three-terminal constant current switching power supply control circuit 10 includes: a reference source 101, a first sampling circuit 102, a second sampling circuit 103, a time-sharing control driving module 104, a power switch module 105, a valley detection module 106, and a power supply control module 107.
Wherein the reference source 101 is connected between the charging terminal 108 and the ground terminal 109, the reference source 101 generating a reference voltage according to a power supply signal or a charging signal; specifically, the charging end 108 is externally connected with a charging module, if the power signal exists, the reference source 101 generates a reference voltage according to the power signal, and the power signal charges the charging module through the charging end 108; if the reference source 101 cannot receive the power signal, the charging module outputs a charging signal through the charging terminal 108 at this time, and the reference source 101 generates a reference voltage according to the charging signal.
Specifically, the first sampling circuit 102 is connected to the reference source 101, and the first sampling circuit 102 samples a difference between the reference voltage and the voltage of the ground terminal 109 according to a first control driving signal to obtain a first sampling signal; when the first sampling circuit 102 receives the reference voltage generated by the reference source 101 and the voltage of the ground terminal 109, the first sampling circuit 102 samples the difference between the reference voltage and the voltage of the ground terminal 109 to obtain a first sampling signal because the reference voltage and the voltage of the ground terminal 109 are not equal.
Specifically, the second sampling circuit 103 is connected to the reference source 101, and the second sampling circuit 103 samples the difference between the voltage of the charging terminal 108 and the reference voltage according to the second control driving signal to obtain a second sampling signal. The time-sharing control driving module 104 is connected with the first sampling circuit 102 and the second sampling circuit 103, and when the first sampling circuit 102 transmits a first sampling signal and the second sampling circuit 103 transmits a second sampling signal to the time-sharing control driving module 104, the time-sharing control driving module 104 generates a first control driving signal, a second control driving signal and a turn-off signal according to the first sampling signal and the second sampling signal; further, if the first sampling signal and the second sampling signal are inverted, the time-sharing control driving module 104 outputs the turn-off signal; the time-sharing control driving module 104 detects the valley signal within a predetermined time threshold or generates a conducting signal exceeding the predetermined time threshold, wherein the predetermined time threshold is set in advance.
Specifically, the power switch module 105 is connected between the power end 110 and the ground end 109, the power switch module 105 outputs a dc voltage signal under the driving of the turn-off signal, wherein the power end 110 is used for inputting a dc power supply, and when the power switch module 105 is connected between the power end 110 and the ground end 109, the power switch module 105 outputs a dc voltage signal under the driving of the turn-off signal according to the dc power supply; it can be understood that if the time-sharing control driving module 104 outputs the on signal to the power switch module 105, the power switch module 105 is in the on state and does not output the dc voltage signal.
Specifically, the valley bottom detection module 106 is connected with the time-sharing control driving module 104, and the valley bottom detection module 106 generates a valley bottom signal when detecting the demagnetizing resonance voltage signal of the power switch module 105; when the time-sharing control driving module 104 transmits the turn-off signal to the power switch module 105, the voltage output by the power switch module 105 outwards generates certain fluctuation when receiving the turn-off signal, if the valley bottom detecting module 106 detects the valley bottom occurrence time of the fluctuation voltage output by the power switch module 105, the valley bottom detecting module 106 generates a valley bottom signal and transmits the valley bottom signal to the time-sharing control driving module 104, so that feedback control is formed between the valley bottom detecting module 106 and the time-sharing control driving module 104, and the three-terminal constant-current switch power supply control circuit 10 is ensured to have higher stability.
Specifically, the power supply control module 107 is connected between the reference source 101 and the power switch module 105, and the power supply control module 107 generates the power supply signal according to the dc voltage signal output by the power switch module 105 and transmits the power supply signal to the reference source 101.
Specifically, the first sampling circuit 102 includes: a first switch K1, a first comparator Comp1, and a first capacitor C1; the first switch K1 is connected between the reference source 101 and the non-inverting input terminal of the first comparator Comp1, the first capacitor C1 is connected between the charging terminal 108 and the non-inverting input terminal of the first comparator Comp1, the inverting input terminal of the first comparator Comp1 is connected to the ground terminal 109, and the output terminal of the first comparator Comp1 outputs the first sampling signal.
Specifically, the first capacitor C1 is connected between the non-inverting input terminal and the charging terminal 108 of the first comparator Comp1, and the voltage at two ends of the first capacitor C1 is the difference between the voltage at the charging terminal 108 and the reference voltage generated by the reference source 101, and since there is a difference between the reference voltage connected to the non-inverting input terminal of the first comparator Comp1 and the voltage connected to the grounding terminal connected to the inverting input terminal of the first comparator Comp1, the first comparator Comp1 can output the first sampling signal according to the difference; it will be appreciated that when the input voltages at the non-inverting input and the inverting input of the first comparator Comp1 change, the first sampling signal output from the output of the first comparator Comp1 also changes accordingly.
Specifically, the second sampling circuit 103 includes: a second switch K2, a second capacitor C2, and a second comparator Comp1; the second switch K2 is connected between the reference source 101 and the non-inverting input terminal of the second comparator Comp2, the second capacitor C2 is connected between the non-inverting input terminal of the second comparator Comp2 and the ground terminal 109, the inverting input terminal of the second comparator Comp2 is connected with the charging terminal 108, and the output terminal of the second comparator Comp2 outputs the second sampling signal.
Specifically, the power switch module 105 includes a power switch tube M0; the G end of the power switch tube M0 is connected to the time-sharing control driving module 104, the D end of the power switch tube M0 is connected to the power supply end 110, the S end of the power switch tube M0 is connected to the ground end 109, and the JS end of the power switch tube M0 outputs the dc voltage signal.
Optionally, the power switch tube M0 is a JFET (Junction Field-Effect Transistor, junction Field effect transistor), and since the D end of the power switch tube M0 is connected to the power supply terminal 110, the D end of the power switch tube M0 is connected to the dc power supply, when the time-sharing control driving module 104 transmits the turn-off signal to the G end of the power switch tube M0, at this time, the equivalent impedance between the D end and the S end of the power switch tube M0 is larger, the JS end of the power switch tube M0 is at a high level, and the power switch tube M0 is in an off stage, i.e., the JS end of the power switch tube M0 outputs the dc voltage signal to the power supply control module 107; if the time-sharing control driving module 104 transmits the on signal to the G end of the power switch tube M0, the equivalent impedance between the D end and the S end of the power switch tube M0 is very small at this time, i.e. the voltage difference between the power supply end 110 and the ground end 109 is small, the JS end of the power switch tube M0 is at a low level, the power switch tube M0 is in a conducting stage, and the JS end of the power switch tube M0 does not output a dc voltage signal to the power supply control module 107 at this time.
In order to better explain the embodiment of the present invention, the following describes, by way of a specific example, the working procedure of the three-terminal constant current switching power supply control circuit 10, specifically as follows:
in the initial state, the power switch tube M0 is in an off phase, at this time, a dc power is input to the power switch tube M0 through the power supply terminal 110, the voltage of the D terminal of the power switch tube M0 rises, and the JS terminal of the power switch tube M0 outputs a dc voltage signal for providing electric energy to the power supply control module 107; the power supply control module 107 outputs a power supply signal to the reference source 101 according to the dc voltage signal, at this time, the voltage of the charging end 108 rises, after the voltage of the charging end 108 continuously rises to reach the working voltage, the reference source 101 generates a reference voltage according to the power supply signal, at this time, the first switch K1 and the second switch K2 are in a closed state, the first sampling circuit 102 samples the difference between the reference voltage and the voltage of the ground end 109, the first comparator Comp1 outputs a first sampling signal, and similarly, the second sampling circuit 103 samples the difference between the voltage of the charging end 108 and the reference voltage, and the second comparator Comp2 outputs a second sampling signal; when the first sampling signal and the second sampling signal remain stable, the time-sharing control driving module 104 generates a first control driving signal to output to the first switch K1 and generates a second control driving signal to output to the second switch K2, respectively, for controlling the first switch K1 to be turned off and the second switch K2 to be turned off, and the time-sharing control driving module 104 outputs a conducting signal to the power switch module 105, for controlling the power switch tube M0 to be turned on.
When the power switch tube M0 is turned on, the power supply control module 107 does not output a power signal to the reference source 101, the homodromous input end of the first comparator Comp1 is connected to the first capacitor C1, the first comparator Comp1 outputs a first sampling signal according to the voltage difference between the in-phase input end and the anti-phase input end of the first comparator Comp1, and the second comparator Comp2 outputs a second sampling signal according to the voltage difference between the in-phase input end and the anti-phase input end of the second comparator Comp2, when the time-sharing control driving module 104 detects that the first sampling signal and the second sampling signal turn over, the time-sharing control driving module 104 outputs an off signal to the power switch tube M0, at this time, the power switch tube M0 returns to the off stage, i.e. the JS end of the power switch tube M0 outputs a direct-current voltage signal, and at this time, the time-sharing control driving module 104 generates a first control driving signal to be output to the first switch K1 and generates a second control driving signal to be output to the second switch K2, so as to control the first switch K1 and the second switch K2 to be turned on.
When the power switch tube M0 is turned off, the voltage output by the power switch tube M0 will generate corresponding fluctuation, that is, the voltage at the G end of the power switch tube M0 will generate certain fluctuation, the valley bottom detection module 106 continuously detects the voltage at the G end of the power switch tube M0, and if the valley bottom detection module 106 detects the valley bottom signal in the voltage at the G end of the power switch tube M0 within the predetermined time threshold or does not detect the valley bottom signal beyond the predetermined time threshold, the time-sharing control driving module 104 outputs a conducting signal to the G end of the power switch tube M0 for controlling the power switch tube M0 to conduct, at this time, the JS end of the power switch tube M0 outputs a low level, that is, the JS end of the power switch tube M0 does not output a direct current voltage signal.
As can be seen from the above analysis of the workflow of the three-terminal constant current switching power supply control circuit 10, the contribution degree of the first sampling circuit 102 and the second sampling circuit 103 to the control circuit 10 is 50%; if the uniformity of the first sampling circuit 102 composed of the first switch K1, the first capacitor C1 and the first comparator Comp1 is ±5%, that is, the uniformity distribution of the first sampling circuit 102 follows a gaussian distribution of μ1=1, σ1=0.0167, which is expressed as:
X1～N(μ1,σ1 2 )＝N(1,0.0167 2 )；
if the uniformity (±3σ) of the second sampling circuit 103 composed of the second switch K2, the second capacitor C2 and the second comparator Comp2 is ±5%, that is, the uniformity distribution of the second sampling circuit 103 is compliant with a gaussian distribution μ2=1, σ2=0.0167, it is noted that:
X2～N(μ2,σ2 2 )＝N(1,0.0167 2 )；
when the first sampling circuit 102 and the second sampling circuit 103 are respectively in independent working states, the control system composed of the first sampling circuit 102 and the second sampling circuit 103 has consistency distribution of x3=50% > x1+50% > X2 under the condition of time-sharing control, and the distribution is denoted as X3-N (μ3, σ3) 2 ) According to Gaussian theory:
μ3＝50％*μ1+50％*μ2＝1；
σ3 2 ＝(50％*σ1) 2 +(50％*σ2) 2 ＝0.0118 2 ；
namely X3 to N (1,0.0118) 2 ) The method comprises the steps of carrying out a first treatment on the surface of the The control system consisting of the first sampling circuit 102 and the second sampling circuit 103 is identical to + -3.53%.
If the first sampling circuit 102 and the second sampling circuit 103 are respectively in the non-independent working state, the correlation ρ= -0.5 between the first sampling circuit 102 and the second sampling circuit 103, where "-" represents the opposite polarity, and 0.5 represents the similarity, at this time, the control system composed of the first sampling circuit 102 and the second sampling circuit 103 has a consistency distribution of x3=50% > x1+50% > X2 under the condition of time-sharing control, denoted as X3-N (μ3, σ3) 2 ) According to Gaussian theory:
μ3＝50％*μ1+50％*μ2＝1；
σ3 2 ＝(50％*σ1) 2 +(50％*σ2) 2 +50％*ρ*σ1*σ2＝0.0083 2 ；
namely X3 to N (1,0.0083) 2 ) At this time, the first sampling circuit 102 is used for samplingAnd the control system consistency of the second sampling circuit 103 is + -2.5%.
Through the above analysis, no matter whether the first sampling circuit 102 and the second sampling circuit 103 are in independent operation states or non-independent operation states, the random error term generated when the first sampling circuit 102 outputs the first sampling signal and the random error term generated when the second sampling circuit 103 outputs the second sampling signal have the mutual offset effect; further, when the first sampling circuit 102 and the second sampling circuit 103 are highly matched at the time of design, the consistency of the first sampling circuit 102 and the second sampling circuit 103 is reduced to less than ±3%, thereby effectively reducing the random error of the three-terminal constant current switching power supply control circuit 10.
Fig. 2 shows a circuit structure diagram of a three-terminal constant current switching power supply control chip 20 according to an embodiment of the present invention, which is described in detail below:
as shown in fig. 2, the three-terminal constant current switching power supply control chip 20 includes a three-terminal constant current switching power supply control circuit 10, a charging pin VCC, a power supply pin D, and a ground pin GND.
The charging pin VCC is connected with a charging end 108 of the three-terminal constant current switching power supply control circuit 10, and is used for charging signals, and the charging signals are generated by a charging module externally connected with the charging pin VCC; the power supply pin D is connected with the power supply end 110 of the three-terminal constant current switching power supply control circuit 10 and is used for outputting a direct current power supply so as to drive the three-terminal constant current switching power supply control chip 20 to act; the ground pin GND is connected with the ground end 109 of the three-terminal constant current switching power supply control circuit 10; specifically, when power is input to the three-terminal constant current switching power supply control chip 20 through the power supply pin D, the three-terminal constant current switching power supply control chip 20 can maintain a constant state of voltage between voltages output therefrom.
Fig. 3 shows a circuit configuration diagram of an LED (Light Emitting Diode ) driving circuit according to an embodiment of the present invention, which is described in detail below:
as shown in fig. 3, the LED driving circuit is used for driving the LED array 304, wherein the LED array 304 includes at least one LED lamp bead, and the LED driving circuit includes a three-terminal constant current switching power supply controlChip 20, rectifying and filtering module 301, energy storage circuit 302, charging circuit 303 and sampling resistor R CS 。
The rectifying and filtering module 301 outputs a direct current power supply; specifically, when the input end of the rectifying and filtering module 301 is connected to an ac power source, the rectifying and filtering module 301 can directly output a dc power source according to the ac power source. The energy storage circuit 302 is connected between the first end of the rectifying and filtering module 301 and the power supply pin D of the three-terminal constant current switching power supply control chip 20, the energy storage circuit 302 is used for storing electric energy, and the LED array 304 is connected in parallel with the energy storage circuit 302, specifically, when the rectifying and filtering module 301 outputs a direct current power supply to the energy storage circuit 302, the energy storage circuit 302 stores corresponding electric energy and simultaneously outputs stable electric energy to the LED array 304, so as to keep the working voltage at two ends of the LED array 304 constant.
Specifically, the charging circuit 303 is connected between the charging pin VCC of the three-terminal constant current switching power supply control chip 20 and the second end of the rectifying and filtering module 301; according to the above analysis process for the three-terminal constant current switching power supply control chip 20, the three-terminal constant current switching power supply control chip 20 can output electric energy to the charging circuit 303 through the charging pin VCC, i.e. a charging process; the charging circuit 303 can also output electric energy to the three-terminal constant current switching power supply control chip 20 through the charging pin VCC, i.e. a discharging process. Sampling resistor R CS Is connected between the ground pin GND of the three-terminal constant current switching power supply control chip 20 and the second terminal of the rectifying and filtering module 301.
Specifically, the rectifying and filtering module 301 includes a first diode D0, a second diode D1, a third diode D2, a fourth diode D3, and a third capacitor C IN ；
Wherein the anode of the first diode D0, the anode of the second diode D1, the cathode of the third diode D2 and the cathode of the fourth diode D3 are used for connecting an alternating current power supply AC; cathode of first diode D0, cathode of second diode D1 and third capacitor C IN The first end 301 of the rectifying and filtering module, the anode of the third diode D2, the anode of the fourth diode D3 and the third capacitor C IN Is the second end of the rectifying and filtering module 301.
Specifically, when an ac voltage is input through the anode of the first diode D0, the anode of the second diode D1, the cathode of the third diode D2, and the cathode of the fourth diode D3, the first end and the second end of the rectifying and filtering module 301 output a dc power supply after the rectifying and filtering module 301 rectifies and filters due to the unidirectional conductivity of the diodes, so that the rectifying and filtering module 301 implements a conversion process between an ac signal and a dc signal.
Specifically, the LED driving circuit further includes a third switch F 0 Third switch F 0 A third switch F connected between the anode of the first diode D0 and the cathode of the third diode D2 and the AC power supply AC 0 For controlling the working state of the LED driving circuit, if the third switch F 0 When the LED driving circuit is disconnected, the LED driving circuit is in a stop state, and at the moment, the LED array 304 does not work; if the third switch F 0 The LED driving circuit drives the LED array 304 to remain in normal operation.
Specifically, the tank circuit 302 includes: filter capacitor C L Inductance L 0 And a flywheel diode D4.
Wherein the filter capacitor C L A filter capacitor C connected to the first terminal of the rectifying and filtering module 301 and the cathode of the freewheeling diode D4 L Second terminal of (2) and inductance L 0 Is connected with the first end of the inductor L 0 The anode of the freewheeling diode D4 is connected to the power pin D of the three-terminal constant current switching power control chip 20.
Specifically, the freewheeling diode D4 can ensure that the direct current power input to the power pin D of the switching power supply control chip 20 will not generate abrupt change, and when the switch in the LED driving circuit is turned off or turned on suddenly, the freewheeling diode D4 connected to the power pin D of the switching power supply control chip 20 can make the voltage output by the energy storage circuit 302 be prevented from being in a stable change state, so as to avoid damaging related electronic components; therefore, the tank circuit 302 and the switching power supply control chip 20 can output a constant power supply to the LED array 304.
Specifically, the charging circuit 303 includes a power supply capacitor C VCC The method comprises the steps of carrying out a first treatment on the surface of the Power supply capacitor C VCC And the charging pin VCC of the three-terminal constant-current switching power supply control chip 20 is connected with the second end of the rectifying and filtering module 301.
The operation of the above-described LED driving circuit will be described below with reference to fig. 1-3.
When the direct current power is output to the energy storage circuit 302 through the rectifying and filtering module 301, if the control power switch tube M0 in the three-terminal constant current switch power control chip 20 is in the conducting stage, the inductance L in the energy storage circuit 302 0 Corresponding to the storage of the electric energy, the capacitor C being supplied with power at this time VCC During the discharge process; if the control power switch tube M0 in the three-terminal constant current switch power supply control chip 20 is in the off stage, the inductor L 0 The power supply pin D of the three-terminal constant current switching power supply control chip 20 is discharged with electric energy, and the capacitor C is supplied with power at the moment VCC During the charging process; that is, the three-terminal constant current switching power supply control chip 20 can realize how much energy is released to the energy storage circuit 302 in each charging or discharging process by switching on or off the internal power switch tube M0; further, since the LED array 304 is connected in parallel with the tank circuit 302, the three-terminal constant current switching power supply control chip 20 indirectly controls the working voltages at two ends of the LED array 304; therefore, the working voltage at the two ends of the LED array 304 can be regulated to be always kept in a constant state through the three-end constant-current switching power supply control chip 20, and the safe working of the LED array is ensured.
Fig. 4 shows a schematic structural diagram of an LED lamp 40 according to an embodiment of the present invention, which is described in detail below:
the LED light fixture 40 comprises an LED array 304, the LED array 304 comprising at least one LED light bead, wherein the LED light fixture 40 further comprises an LED driving circuit 50 as described above; the LED array 304 is connected to the LED driving circuit 50, and the LED driving circuit 50 can drive the LED array 304 to be in a stable operation state.
According to the embodiment of the invention, in the three-terminal constant current switching power supply control chip, the integrated power switch module can output a direct current voltage signal, so that electronic components in the three-terminal constant current switching power supply control chip are in a stable running state, the internal structure of the three-terminal constant current switching power supply control chip is simplified, the manufacturing cost of the control chip is reduced, the number of components in the control chip is reduced, and the reliability of the control chip is improved; the first sampling circuit and the second sampling circuit which are introduced simultaneously can counteract random error items generated by each other under the condition of time-sharing control, so that the control performance of the three-terminal constant-current switching power supply control chip is improved; when the three-terminal constant-current switching power supply control chip is applied to the LED drive circuit, the voltage at two ends of the LED array can be constant through the control chip, so that the stable operation of the LED array is ensured; the three-terminal constant current switching power supply control chip effectively solves the problems of high manufacturing cost, larger random error and poor control performance of the three-terminal constant current switching power supply control chip in the prior art.
It should be noted that in this document relational terms such as first and second are used solely to distinguish one entity from another entity without necessarily requiring or implying any actual such relationship or order between such entities. And the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a product or structure that comprises a list of elements is inherent to the element. Without further limitation, an element defined by the statement "comprising … …" or "comprising … …" does not exclude the presence of additional elements in a process, method, article or terminal device comprising the element. Further, herein, "greater than," "less than," "exceeding," and the like are understood to not include the present number; "above", "below", "within" and the like are understood to include this number.
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.
Claims (10)
1. The utility model provides a three terminal constant current switching power supply control circuit which characterized in that includes:
the reference source is connected between the charging end and the grounding end and is used for generating reference voltage according to a power supply signal or a charging signal;
the first sampling circuit is connected with the reference source and is used for sampling the difference between the reference voltage and the voltage of the grounding end according to a first control driving signal to obtain a first sampling signal;
the second sampling circuit is connected with the reference source and is used for sampling the difference between the voltage of the charging end and the reference voltage according to a second control driving signal to obtain a second sampling signal;
the time-sharing control driving module is connected with the first sampling circuit and the second sampling circuit and is used for generating the first control driving signal, the second control driving signal and the turn-off signal according to the first sampling signal and the second sampling signal and generating a turn-on signal when a valley signal is detected within a preset time threshold value or the preset time threshold value is exceeded; if the first sampling signal and the second sampling signal are overturned, the time-sharing control driving module outputs the turn-off signal;
the power switch module is connected between the power end and the grounding end and is used for outputting a direct-current voltage signal under the drive of the turn-off signal;
the valley detection module is connected with the time-sharing control driving module and used for generating the valley signal when detecting the demagnetizing resonance voltage signal of the power switch module; a kind of electronic device with high-pressure air-conditioning system
And the power supply control module is connected between the reference source and the power switch module and is used for generating the power supply signal according to the direct-current voltage signal.
2. The three-terminal constant current switching power supply control circuit according to claim 1, wherein the first sampling circuit comprises: a first switch, a first comparator, and a first capacitor;
the first switch is connected between the reference source and the non-inverting input end of the first comparator, the first capacitor is connected between the charging end and the non-inverting input end of the first comparator, the inverting input end of the first comparator is connected with the grounding end, and the output end of the first comparator outputs the first sampling signal.
3. The three-terminal constant current switching power supply control circuit according to claim 1, wherein the second sampling circuit comprises: a second switch, a second capacitor and a second comparator;
the second switch is connected between the reference source and the non-inverting input end of the second comparator, the second capacitor is connected between the non-inverting input end of the second comparator and the grounding end, the inverting input end of the second comparator is connected with the charging end, and the output end of the second comparator outputs the second sampling signal.
4. The three-terminal constant current switching power supply control circuit according to claim 1, wherein the power switching module comprises a power switching tube;
the G end of the power switch tube is connected with the time-sharing control driving module, the D end of the power switch tube is connected with the power supply end, the S end of the power switch tube is connected with the grounding end, and the JS end of the power switch tube outputs the direct-current voltage signal.
5. A three-terminal constant current switching power supply control chip, characterized by comprising the three-terminal constant current switching power supply control circuit according to any one of claims 1 to 4;
the charging pin is connected with the charging end of the three-terminal constant-current switching power supply control circuit and used for being connected with the charging signal;
the power supply pin is connected with the power supply end of the three-terminal constant-current switching power supply control circuit and used for being connected with a direct-current power supply; and
and a ground pin connected with the ground end of the three-terminal constant current switching power supply control circuit.
6. An LED driving circuit for driving an LED array, the LED array comprising at least one LED light bead, comprising:
the three-terminal constant current switching power supply control chip according to claim 5;
the rectification filter module is used for outputting the direct current power supply;
the energy storage circuit is connected between the first end of the rectifying and filtering module and the power pin of the three-terminal constant-current switching power supply control chip and used for storing electric energy, and the LED array is connected with the energy storage circuit in parallel;
the charging circuit is connected between the charging pin of the three-terminal constant-current switching power supply control chip and the second end of the rectifying and filtering module and is used for generating the charging signal; and
and the sampling resistor is connected between the ground pin of the three-terminal constant current switching power supply control chip and the second end of the rectifying and filtering module.
7. The LED driving circuit of claim 6, wherein the rectifying and filtering module comprises a first diode, a second diode, a third diode, a fourth diode, and a third capacitor;
wherein the anode of the first diode, the anode of the second diode, the cathode of the third diode and the cathode of the fourth diode are used for connecting an alternating current power supply;
the cathode of the first diode, the cathode of the second diode and the first end of the third capacitor are the first ends of the rectifying and filtering module, and the anode of the third diode, the anode of the fourth diode and the second end of the third capacitor are the second ends of the rectifying and filtering module.
8. The LED driving circuit of claim 7, further comprising a third switch;
the third switch is connected between the anode of the first diode and the cathode of the third diode and the alternating current power supply.
9. The LED driving circuit of claim 6, wherein the tank circuit comprises: a filter capacitor, an inductor and a flywheel diode;
the first end of the filter capacitor and the cathode of the freewheeling diode are connected with the first end of the rectifying and filtering module, the second end of the filter capacitor is connected with the first end of the inductor, and the second end of the inductor and the anode of the freewheeling diode are connected with the power pin of the three-terminal constant-current switching power supply control chip.
10. The LED driving circuit of claim 6, wherein the charging circuit comprises a supply capacitor;
and the power supply capacitor is connected between a charging pin of the three-terminal constant-current switching power supply control chip and the second end of the rectifying and filtering module.
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| CN201711456875.2A CN108055730B (en) | 2017-12-28 | 2017-12-28 | Constant-current switching power supply control circuit, chip and LED driving circuit |
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| CN201711456875.2A CN108055730B (en) | 2017-12-28 | 2017-12-28 | Constant-current switching power supply control circuit, chip and LED driving circuit |
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| CN108055730B true CN108055730B (en) | 2023-07-11 |
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| CN116088362B (en) * | 2022-11-01 | 2023-09-01 | 深圳市谷粒科技有限公司 | Device micro-power consumption intelligent control device, method, system and medium |
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| CN105979662A (en) * | 2016-07-06 | 2016-09-28 | 深圳市明微电子股份有限公司 | LED constant current drive circuit and LED lighting device |
| CN205793545U (en) * | 2016-07-06 | 2016-12-07 | 深圳市明微电子股份有限公司 | A kind of constant current driver circuit for LED and LED light device |
| CN207835866U (en) * | 2017-12-28 | 2018-09-07 | 深圳市富满电子集团股份有限公司 | Constant-current switch power source control circuit, chip and LED drive circuit |
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| CN105979662A (en) * | 2016-07-06 | 2016-09-28 | 深圳市明微电子股份有限公司 | LED constant current drive circuit and LED lighting device |
| CN205793545U (en) * | 2016-07-06 | 2016-12-07 | 深圳市明微电子股份有限公司 | A kind of constant current driver circuit for LED and LED light device |
| CN207835866U (en) * | 2017-12-28 | 2018-09-07 | 深圳市富满电子集团股份有限公司 | Constant-current switch power source control circuit, chip and LED drive circuit |
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