CN112702815B - Switch buck type LED constant current control circuit, system and method - Google Patents
Switch buck type LED constant current control circuit, system and method Download PDFInfo
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- CN112702815B CN112702815B CN201911000879.9A CN201911000879A CN112702815B CN 112702815 B CN112702815 B CN 112702815B CN 201911000879 A CN201911000879 A CN 201911000879A CN 112702815 B CN112702815 B CN 112702815B
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Abstract
The invention provides a switch buck LED constant current control circuit, a system and a method, comprising the following steps: an average current comparison module comparing the current detection sampling signal with an average reference; a peak current comparing module comparing the current detection sampling signal with a peak reference; an adaptive clock generation module that generates a shutdown end signal; a PWM logic control module for generating logic control signals; and a driving module. The power switch tube is turned on in the same time when the current detection sampling signal rises to the average reference and exceeds the average reference, and then the power switch tube is turned off; if the current detection sampling signal is larger than the peak value base criterion, the power switch tube is turned off in advance, meanwhile, the turn-off reference signal is adjusted, and when the preset charging signal is larger than the turn-off reference signal, the power switch tube is turned on again, and the next new PWM period is started. The invention can realize smaller current ripple and high-precision output current, and has better linear adjustment rate and load adjustment rate.
Description
Technical Field
The invention relates to the field of LED constant current control, in particular to a switch buck LED constant current control circuit, a system and a method.
Background
The traditional switch buck type LED controller adopts a peak current detection mode with fixed clock frequency, is influenced by inductance ripple, and has poor current precision on an output LED light-emitting unit; when the external power supply and the load change, the inductance value needs to be adjusted to ensure that the output inductance current works in a continuous conduction mode, and the selection of the inductance value influences the accuracy and ripple of the LED current.
In the conventional LED control scheme, after the power supply VDD is powered on, the current detection sampling signal is compared with the reference voltage to generate a charging end signal, the charging end signal and the clock signal are controlled by PWM logic to generate a logic control signal, and then the logic control signal is driven by the output front stage to generate a gate driving signal of an external power device, so as to control the power device to be turned on and off, thereby controlling the current (current peak and ripple) on the external LED light emitting unit.
The driving time sequence of the continuous conduction mode is shown in fig. 1, after the power supply VDD is powered on, the internal driving circuit starts to work, the internal PWM logic controls the external inductor to periodically charge and discharge, and the corresponding current i_led flows through the external LED light emitting unit. One PWM period is amplified, with the timing shown in fig. 2: in a fixed PWM period (for example, the fixed clock period may be set to 7 us), the gate driving signal DRV is set to a logic high level, the power device is turned on, the inductor current is charged, the level of the feedback signal CS slowly rises to the reference voltage VREF, when the charging end signal DISCHARGE is detected to be high, DRV becomes a logic low level, the power device is turned off, and the inductor current is discharged.
In continuous conduction mode: the peak value of the output current i_led is: ipeak=vref/r_sense, where Ipeak is the peak current and r_sense is the resistance of the sampling resistor. The ripple of the i_led is: Δi=v LED * Toff/L, where V LED For the voltage drop across the LED lighting unit, L is the inductance and Toff is the fixed discharge time. Since it is a buck type LED controller, the fixed discharge time Toff is determined by the voltage drop V across the LED lighting unit LED The input voltage Vin and PWM period T are determined by: toff= (1-V) LED Vin) T, so: Δi=v LED *(1-V LED Vin) T/L, the accuracy of the output current i_led is affected by the peak value Ipeak and the ripple Δi.
In order to ensure constant output current, proper inductance value is required to ensure that the loop works in a continuous conduction mode, and the calculation formula of the minimum inductance value is as follows: l1>V LED *(1-V LED Vin) T r_sense/VREF, when Δi=ipeak=vref/r_sense, the output operates in a critical continuous conduction mode. To achieve better current accuracy, it is necessary to ensure that the ripple of the inductor current is small, for example, Δi=40%. Ipeak is set, and the inductance is increased to: l1>2.5*V LED *(1-V LED Vin) T r_sense/VREF. If the set external inductance is small, the discontinuous conduction mode is easy to enter, and the ripple and the precision of the I_LED are affected.
In order to ensure the accuracy of the output current, the conventional LED control loop has fixed frequency and must ensure that the controller works in a continuous conduction mode. When the external inductance is smaller or the set output I_LED current is smaller, vin, an LED light-emitting unit and other loads are changed, a discontinuous conduction mode is easy to enter, and the output current precision is affected. Therefore, how to ensure that the LED control loop is not affected by the input voltage and the LED lighting unit, to improve the output current accuracy and reduce the output ripple is one of the problems to be solved by those skilled in the art.
Disclosure of Invention
In view of the above drawbacks of the prior art, the present invention is directed to providing a switch buck LED constant current control circuit, system and method, which are used for solving the problem of low accuracy of the output current of the LED control circuit in the prior art.
To achieve the above and other related objects, the present invention provides a switch buck LED constant current control circuit, which at least includes:
the device comprises an average current comparison module, a peak current comparison module, a self-adaptive clock generation module, a PWM logic control module and a driving module;
the average current comparison module receives a current detection sampling signal of the buck LED circuit and is used for comparing the current detection sampling signal with an average reference and obtaining a first comparison result;
The peak current comparison module receives the current detection sampling signal, and is used for comparing the current detection sampling signal with a peak reference and obtaining a second comparison result; the average reference is less than the peak reference;
the self-adaptive clock generation module adjusts the level of the turn-off reference signal based on the inverse logic signal of the second comparison result and generates a corresponding turn-off ending signal;
the PWM logic control module is connected with the output ends of the average current comparison module, the peak current comparison module and the self-adaptive clock generation module, adjusts the on time of a logic control signal based on the first comparison result and the second comparison result, and adjusts the off time of the logic control signal based on the off end signal so as to realize constant current output of the step-down LED circuit and reduce output current ripple;
the driving module is connected to the output end of the PWM logic control module, and drives a power switching tube in the step-down LED circuit to be turned on or off based on the logic control signal.
Optionally, the adaptive clock generation module includes a turn-off reference signal control unit and a turn-off end signal generation unit;
The turn-off reference signal control unit receives an inverted logic signal of the second comparison result, and generates a pull-down control signal when the current detection sampling signal is greater than the peak reference; generating a pull-up control signal when the current sense sampling signal is less than the peak reference;
the turn-off end signal generating unit receives the pull-down control signal and the pull-up control signal to adjust the level of a turn-off reference signal, the pull-down control signal controls the turn-off reference signal to decrease the level, and the pull-up control signal controls the turn-off reference signal to increase the level; and comparing a preset charging signal with the turn-off reference signal, and generating the turn-off ending signal when the preset charging signal is larger than the turn-off reference signal.
More optionally, the off reference signal control unit includes a first inverter, a first nand gate, a second nand gate, a third nand gate, a fourth nand gate, and a second inverter;
the input end of the first NAND gate is respectively connected with the inverted logic signal of the second comparison result and the output end of the second NAND gate; the input end of the first inverter receives an inversion logic signal of the second comparison result; the input end of the second NAND gate is respectively connected with the output end of the first inverter and the output end of the first NAND gate; the input end of the third NAND gate is respectively connected with the output end of the first NAND gate and a pulse signal, the input end of the second inverter is connected with the output end of the third NAND gate, and the output end outputs the pull-down control signal; and the input end of the fourth NAND gate is respectively connected with the output end of the second NAND gate and the pulse signal, and the output end outputs the pull-up control signal.
More optionally, the turn-off end signal generating unit includes a first current source, a pull-up tube, a pull-down tube, a second current source, a first charging capacitor, a first switch, a third current source, a second charging capacitor and a comparator;
the first current source, the pull-up tube, the pull-down tube and the second current source are sequentially connected in series between a power supply and the ground, a connection node of the pull-up tube and the pull-down tube outputs the turn-off reference signal, a control end of the pull-up tube is connected with the pull-up control signal, and a control end of the pull-down tube is connected with the pull-down control signal; one end of the first charging capacitor is connected with the turn-off reference signal, and the other end of the first charging capacitor is grounded; one end of the first switch is connected with the turn-off reference signal, and the other end of the first switch is grounded after being connected with the bias voltage;
one end of the third current source is connected with a power supply, and the other end of the third current source is connected with the second charging capacitor; the other end of the second charging capacitor is grounded; the connection node of the third current source and the second charging capacitor outputs the preset charging signal;
and the input end of the comparator is respectively connected with the turn-off reference signal and the preset charging signal, and outputs the turn-off ending signal.
More optionally, the PWM logic control module includes a turn-on signal generating unit and a logic control signal generating unit;
the conducting signal generating unit receives the first comparison result and the second comparison result, outputs an effective conducting signal in the first time when the current detection sampling signal rises to the average reference and the first time when the current detection sampling signal exceeds the average reference, and directly fails if the current detection sampling signal is greater than the peak reference;
the logic control signal generating unit is connected with the output ends of the conducting signal generating unit and the adaptive clock generating module and generates the logic control signal based on the conducting signal and the turn-off ending signal.
More optionally, the on signal generating unit includes an oscillator, an adder, and a subtractor;
the adder is connected with the output ends of the oscillator and the average current comparison module, and performs addition operation when the current detection sampling signal rises to the average reference to obtain a counting result corresponding to the first time;
the subtracter is connected with the output ends of the oscillator, the adder and the peak current comparison module, and is used for subtracting the counting result of the adder, and if the current detection sampling signal is smaller than the peak reference, the conducting signal is controlled to be invalid when the subtraction result is zero; and if the current detection sampling signal is larger than the peak value reference, directly controlling the conduction signal to fail.
Optionally, the switch buck type LED constant current control circuit further comprises a short circuit protection module and/or a dimming module; the short-circuit protection module receives the current detection sampling signal, compares the current detection sampling signal with a short-circuit protection reference, and turns off the power switch tube when the current detection sampling signal is larger than the short-circuit protection reference, wherein the short-circuit protection reference is larger than the peak value reference; the dimming module receives a dimming control signal and adjusts values of the average reference and the peak reference based on the dimming control signal.
To achieve the above and other related objects, the present invention provides a switching buck LED constant current control system, which at least includes:
the switch buck-type LED constant current control circuit and the buck-type LED circuit are characterized in that the switch buck-type LED constant current control circuit receives a current detection sampling signal of the buck-type LED circuit and outputs a driving signal of the buck-type LED circuit.
Optionally, the step-down type LED circuit comprises an LED light emitting module, an inductor, a freewheeling diode, a power switch tube and a sampling module;
The positive electrode of the LED light-emitting module is connected with an input power supply, and the negative electrode of the LED light-emitting module is connected with one end of the inductor; the other end of the inductor is connected with the anode of the freewheeling diode; the negative electrode of the freewheel diode is connected with the input power supply; one end of the power switch tube is connected with the positive electrode of the freewheeling diode, the other end of the power switch tube is connected with the sampling module and then grounded, and the control end of the power switch tube is connected with the driving signal; and a connecting node of the power switch tube and the sampling module outputs the current detection sampling signal.
To achieve the above and other related objects, the present invention provides a method for controlling a constant current of a switch buck LED, which at least includes:
monitoring a current detection sampling signal of a buck LED circuit, outputting a valid conduction signal in a period in a first time when the current detection sampling signal rises to the average reference and a first time when the current detection sampling signal exceeds the average reference, and then enabling the conduction signal to fail; if the current detection sampling signal is larger than the peak value reference, the conduction signal is invalid;
reducing a turn-off reference signal when the current detection sampling signal is greater than the peak reference, increasing the turn-off reference signal when the current detection sampling signal is less than the peak reference, comparing a preset charging signal with the turn-off reference signal, and generating the turn-off end signal when the preset charging signal is greater than the turn-off reference signal;
Adjusting a driving signal of the power switch tube based on the on signal and the off end signal to realize constant current output and control ripple of output current;
wherein the average reference is less than the peak reference.
Optionally, the method for obtaining the on signal includes:
when the current detection sampling signal is smaller than the average reference, performing addition operation to obtain a counting result corresponding to the first time;
subtracting the counting result, and if the current detection sampling signal is smaller than the peak value reference, controlling the conducting signal to fail when the subtracting operation result is zero; and if the current detection sampling signal is larger than the peak value reference, directly controlling the conduction signal to fail.
Optionally, when the on signal is valid, the power switch tube in the step-down type LED circuit is controlled to be turned on, when the on signal is invalid, the power switch tube is controlled to be turned off, and when the off end signal is valid, the power switch tube is controlled to be turned on again.
Optionally, the switch buck LED constant current control method further includes: and monitoring the current detection sampling signal, and turning off the power switch tube when the current detection sampling signal is larger than a short-circuit protection reference, wherein the short-circuit protection reference is larger than the peak value reference.
Optionally, the switch buck LED constant current control method further includes: and adjusting the values of the average reference and the peak reference based on a dimming control signal to realize dimming control.
As described above, the switch buck LED constant current control circuit, system and method provided by the invention have the following beneficial effects:
the switching buck LED constant current control circuit, the switching buck LED constant current control system and the switching buck LED constant current control method automatically adjust PWM clock cycles through the internal circuit, control on time through the counter, and finally realize smaller current ripple and high precision of output current by adopting a constant current control mode of average current detection and peak current detection, and have good linear adjustment rate and load adjustment rate.
The switch buck LED constant current control circuit, the system and the method adopt self-adaptive adjustment, can realize small LED output current, and can be widely applied to the field of electronic circuits.
Drawings
Fig. 1 shows a schematic diagram of a driving timing diagram in a continuous conduction mode.
Fig. 2 shows an enlarged schematic diagram of one PWM period for the continuous conduction mode driving timing.
Fig. 3 is a schematic diagram of a structure of the switch buck LED constant current control circuit of the present invention.
Fig. 4 is a schematic diagram showing the structure of the off reference signal control unit according to the present invention.
Fig. 5 is a schematic diagram showing the structure of the turn-off end signal generating unit according to the present invention.
Fig. 6 is a schematic diagram showing the structure of the turn-on signal generating unit according to the present invention.
Fig. 7 is a schematic diagram showing another structure of the switch buck LED constant current control circuit of the present invention.
Fig. 8 shows a schematic diagram of a switch buck LED constant current control system according to the present invention.
FIG. 9 is a timing diagram illustrating the generation of on-time in accordance with the present invention.
FIG. 10 is a timing diagram of the present invention for down-turning off the reference signal.
FIG. 11 is a timing diagram of the up-turn off reference signal according to the present invention.
Fig. 12 is a timing diagram showing the generation of the off-end signal according to the present invention.
Fig. 13 shows an input-output timing diagram of the switching buck LED constant current control circuit, system and method of the present invention.
Fig. 14 is a timing chart showing the discontinuous conduction mode before the output current of the present invention is stabilized.
Fig. 15 is a timing chart showing the continuous conduction mode after the output current of the present invention is stabilized.
Description of element reference numerals
1. Switch step-down LED constant current control system
11. Switch step-down LED constant current control circuit
111. Average current comparison module
112. Peak current comparison module
113. Self-adaptive clock generation module
113a off reference signal control unit
113b off-end signal generating unit
114 PWM logic control module
114a conduction signal generation unit
114a1 oscillator
114a2 adder
114a3 subtracter
115. Driving module
116. Short-circuit protection module
117. Dimming module
117a digital-to-analog conversion unit
12. Step-down LED circuit
121 LED light-emitting module
122. Sampling module
Detailed Description
Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention.
Please refer to fig. 3-15. It should be noted that, the illustrations provided in the present embodiment merely illustrate the basic concept of the present invention by way of illustration, and only the components related to the present invention are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complex.
Example 1
As shown in fig. 3, the present embodiment provides a switching step-down LED constant current control circuit 11, the switching step-down LED constant current control circuit 11 including:
an average current comparison module 111, a peak current comparison module 112, an adaptive clock generation module 113, a PWM logic control module 114, and a driving module 115.
As shown in fig. 3, the average current comparing module 111 receives a current detection sampling signal Vcs of the buck LED circuit, and is configured to compare the current detection sampling signal Vcs with an average reference Vref1, and obtain a first comparison result Cp1.
Specifically, in this embodiment, the non-inverting input terminal of the average current comparing module 111 is connected to the current detection sampling signal Vcs, and the inverting input terminal is connected to the average reference Vref1; a low level is output when the current detection sampling signal Vcs is smaller than the average reference Vref1, and a high level is output when the current detection sampling signal Vcs is larger than the average reference Vref 1. In practical use, the correspondence between the input signal and the polarity of the input terminal can be adjusted by adding an inverter, which is not limited to the present embodiment.
As shown in fig. 3, the peak current comparing module 112 receives the current detection sampling signal Vcs, and is configured to compare the current detection sampling signal Vcs with a peak reference Vref2, and obtain a second comparison result Cp2; the average reference Vref1 is smaller than the peak reference Vref2.
Specifically, in this embodiment, the non-inverting input terminal of the peak current comparing module 112 is connected to the current detection sampling signal Vcs, and the inverting input terminal is connected to the peak reference Vref2; a low level is output when the current detection sampling signal Vcs is smaller than the peak reference Vref2, and a high level is output when the current detection sampling signal Vcs is larger than the peak reference Vref2. In practical use, the correspondence between the input signal and the polarity of the input terminal can be adjusted by adding an inverter, which is not limited to the present embodiment.
As shown in fig. 3, the adaptive clock generation module 113 adjusts the Off reference signal level ref_off based on the inverse logic signal LS of the second comparison result Cp2, and generates a corresponding Off end signal Off.
Specifically, the adaptive clock generation module 113 includes a shutdown reference signal control unit 113a and a shutdown end signal generation unit 113b. The off reference signal control unit 113a receives the inverted logic signal LS of the second comparison result Cp2, and outputs a falling edge of the inverted logic signal LS of the second comparison result Cp2 when the current detection sampling signal Vcs is greater than the peak reference Vref2, generating an effective pull-Down control signal Down, which generates a high-level pulse signal once; when the current detection sampling signal Vcs is smaller than the peak reference Vref2, the inverted logic signal LS of the second comparison result Cp2 remains high, generating an active pull-Up control signal Up, which generates a low-level pulse signal once. The turn-Off end signal generating unit 113b receives the pull-Down control signal Down and the pull-Up control signal Up to adjust the magnitude of the turn-Off reference signal ref_off, compares a preset charging signal RC with the turn-Off reference signal ref_off, and generates the turn-Off end signal Off when the preset charging signal RC is greater than the turn-Off reference signal ref_off.
More specifically, as shown in fig. 4, the off reference signal control unit 113a includes a first inverter not1, a first nand gate nand1, a second nand gate nand2, a third nand gate nand3, a fourth nand gate nand4, and a second inverter not2. The input end of the first nand gate nand1 is connected with the inverted logic signal LS of the second comparison result Cp2 and the output end of the second nand gate nand2 respectively; an input end of the first inverter not1 receives an inverted logic signal LS of the second comparison result Cp 2; the input end of the second NAND gate nand2 is respectively connected with the first inverter not1 and the output end of the first NAND gate nand 1; the input end of the third nand gate nand3 is connected to the output end of the first nand gate nand1 and a pulse signal pulse (when the driving signal Drv output by the driving module 115 becomes low, the pulse width of the pulse signal pulse is set to 300ns in this embodiment, and the pulse width and the source of the pulse signal pulse can be set as required in actual use, but not limited to this embodiment), the input end of the second inverter not2 is connected to the output end of the third nand gate nand3, and the output end outputs the pull-Down control signal Down; the input end of the fourth nand gate nand4 is connected to the output end of the second nand gate nand2 and the pulse signal pulse, and the output end outputs the pull-Up control signal Up. When the current detection sampling signal Vcs is greater than the peak reference Vref2, the second comparison result Cp2 is at a high level, the inverted logic signal LS of the second comparison result Cp2 is at a low level, the pull-Down control signal Down is a high level pulse, and the pull-Up control signal Up is also at a high level, and at this time, the pull-Down control signal Down is active, and the Off reference signal ref_off discharges a reduced level within the high level pulse time; when the current detection sampling signal Vcs is smaller than the peak reference Vref2, the second comparison result Cp2 is kept at a low level, the inverted logic signal LS of the second comparison result Cp2 is kept at a high level, the pull-Down control signal Down is at a low level, and the pull-Up control signal Up is a low level pulse, at this time, the pull-Up control signal Up is active, and the turn-Off reference signal ref_off is charged to increase the level during the low level pulse time.
More specifically, as shown in fig. 5, the turn-off end signal generating unit 113b includes a first current source IBP1, a pull-up pipe MP, a pull-down pipe MN, a second current source IBN1, a first charging capacitor C1, a first switch S1, a third current source IBP2, a second charging capacitor C2, and a comparator COMP. One end of the first current source IBP1 is connected with a power supply VDD, and the other end is connected with a source electrode of the pull-up tube MP; the gate end of the pull-Up pipe MP is connected with the pull-Up control signal Up, and the drain electrode is connected with the drain electrode of the pull-down pipe MN; the gate end of the pull-Down pipe MN is connected with the pull-Down control signal Down, and the source electrode is connected with one end of the second current source IBN 1; the other end of the second current source IBN1 is grounded. One end of the first charging capacitor C1 is connected to the drains of the pull-up tube MP and the pull-down tube MN, and the other end is grounded. One end of the first switch S1 is connected to the drains of the pull-up tube MP and the pull-down tube MN, and the other end is connected to the bias voltage Vbias and then grounded. The drain of the pull-up pipe MP outputs a turn-Off reference signal ref_off. One end of the third current source is connected with a power supply, and the other end of the third current source is connected with the second charging capacitor; the other end of the second charging capacitor is grounded; one end of the third current source IBP2 is connected with the power supply VDD, and the other end of the third current source IBP2 is connected with the upper polar plate of the second charging capacitor C2; the lower polar plate of the second charging capacitor C2 is grounded; the connection node of the third current source IBP2 and the second charging capacitor C2 outputs the preset charging signal RC. The input end of the comparator COMP is respectively connected with the turn-Off reference signal ref_off and the preset charging signal RC, the turn-Off end signal Off is output, when the preset charging signal RC is greater than the turn-Off reference signal ref_off, the turn-Off end signal Off is effective, a high-level pulse is generated, the end of the PWM period is announced, the next new PWM period is entered, and the power switch tube is turned on again. In this embodiment, the inverting input terminal of the comparator COMP is connected to the Off reference signal ref_off, and the non-inverting input terminal is connected to the preset charging signal RC. In practical use, the correspondence between the input signal and the polarity of the input terminal can be adjusted by adding an inverter, which is not limited to the present embodiment.
In this embodiment, the first current source IBP1 and the second current source IBN1 are both uA-level currents, and the first charging capacitor C1 is a pF-level capacitor.
As shown in fig. 3, the PWM logic control module 114 is connected to the output ends of the average current comparing module 111, the peak current comparing module 112, and the adaptive clock generating module 113, adjusts the on time of the logic control signal Predrv based on the first comparing result Cp1 and the second comparing result Cp2, and adjusts the Off time of the logic control signal Predrv based on the Off end signal Off, so as to realize the constant current output of the step-down LED circuit and reduce the output current ripple.
Specifically, the PWM logic control module 114 includes a turn-on signal generating unit 114a and a logic control signal generating unit (not shown). The On signal generating unit 114a receives the first comparison result Cp1 and the second comparison result Cp2, outputs a valid On signal On (in one period, the upper and lower deviation values of the current detection sampling signal Vcs and the average reference voltage Vref1 are equal) in a first time when the current detection sampling signal Vcs rises to the average reference Vref1 and a first time when the current detection sampling signal Vcs exceeds the average reference Vref1, and then the On signal On fails, and if the current detection sampling signal Vcs is greater than the peak reference Vref2, the On signal On fails in advance when the current detection sampling signal Vcs is greater than the peak reference Vref 2. The logic control signal generating unit is connected to the output ends of the On signal generating unit 114a and the adaptive clock generating module 113, and generates the logic control signal Predrv based On the On signal On and the Off end signal Off.
More specifically, as shown in fig. 6, in the present embodiment, the on signal generating unit 114a includes an oscillator 114a1, an adder 114a2, and a subtractor 114a3. The oscillator 114a1 is used to generate a basic clock, which in this implementation has a frequency in the order of MHz. The adder 114a2 is connected to the oscillator 114a1 and the output end of the average current comparing module 111, the power switch tube starts to be turned on, and when the current detection sampling signal Vcs gradually increases to the average reference Vref1, the adder 114a2 starts to perform addition operation from 0 to 1, so as to obtain a count result n, where the count result n corresponds to a time when the current detection sampling signal Vcs is smaller than the average reference Vref1, that is, the first time. The subtractor 114a3 is connected to the oscillator 114a1, the adder 114a2, and the output end of the peak current comparing module 112, and is configured to subtract the count result of the adder 114a2 from n to 1, and continuously increase the current detection sampling signal Vcs until the count result of the adder 114a2 gradually decreases from n to 0, where the time when the current detection sampling signal Vcs is greater than the average reference Vref1 is ensured to be the first time. If the current detection sampling signal Vcs is always smaller than the peak reference Vref2, the On signal On is controlled to be invalid and becomes low level when the subtraction result is zero; with the increase of the current detection sampling signal Vcs, if the current detection sampling signal Vcs is greater than the peak reference Vref2, the subtraction operation is stopped, and the On signal On is directly controlled to fail when the current detection sampling signal Vcs is greater than the peak reference Vref 2. The output of the average current comparing module 111 controls the current detection sampling signal Vcs to be equal to the vertical deviation value of the average reference voltage Vref1, so as to realize constant current output. The output of the peak current comparing module 112 controls the maximum On time of the On signal On, if the current detection sampling signal Vcs is higher than the peak reference Vref2, the peak current comparing module 112 outputs a high level pulse, the subtractor 114a3 stops working immediately, and the On signal On ends in advance and becomes logic low level.
More specifically, the logic control signal generating unit receives the On signal On and the Off end signal Off, and generates the logic control signal Predrv. The logic control signal Predrv controls the power switch tube in the buck LED circuit to be conducted when the On signal On is effective, controls the power switch tube to be turned Off when the On signal On is ineffective, and controls the power switch tube to be turned On again when the Off end signal Off is effective.
As shown in fig. 3, the driving module 115 is connected to the output end of the PWM logic control module 114, and generates a driving signal Drv based on the logic control signal Predrv, for driving the power switching tube in the buck LED circuit to be turned on or off.
In this embodiment, the average current comparing module 111, the peak current comparing module 112, the adaptive clock generating module 113, the PWM logic control module 114 and the driving module 115 are integrated in a chip, and in actual use, the positions of the modules can be set according to actual needs, which is not limited to this embodiment.
Example two
As shown in fig. 7, this embodiment provides a switching buck LED constant current control circuit 11, which is different from the first embodiment in that other functional modules are added.
As an implementation manner of the present invention, the switch buck LED constant current control circuit 11 further includes a short circuit protection module 116. The Short-circuit protection module 116 receives the current detection sampling signal Vcs, compares the current detection sampling signal Vcs with a Short-circuit protection reference Vref3, and outputs a Short-circuit protection signal Short. And when the current detection sampling signal Vcs is larger than the short-circuit protection reference Vref3, the power switch tube is turned off, wherein the short-circuit protection reference Vref3 is larger than the peak reference Vref2. In this embodiment, the non-inverting input terminal of the short-circuit protection module 116 is connected to the current detection sampling signal Vcs, the inverting input terminal is connected to the short-circuit protection reference Vref3, and in actual use, the correspondence between the input signal and the polarity of the input terminal can be adjusted by adding an inverter, which is not limited in this embodiment.
As another implementation manner of the present invention, the switching buck LED constant current control circuit 11 further includes a dimming module 117, where the dimming module 117 receives a dimming control signal DIM and adjusts the values of the average reference Vref1 and the peak reference Vref2 based on the dimming control signal DIM. In this embodiment, the dimming module 117 includes a digital-to-analog conversion unit 117a, and the digital-to-analog conversion unit 117a performs digital-to-analog conversion on the dimming control signal DIM to adjust the values of the average reference Vref1 and the peak reference Vref2, thereby implementing dimming control.
Example III
As shown in fig. 8, the present embodiment provides a switching buck LED constant current control system 1, the switching buck LED constant current control system 1 includes: the switching step-down type LED constant current control circuit 11 and the step-down type LED circuit 12.
As shown in fig. 8, the switching buck LED constant current control circuit 11 receives a current detection sampling signal of the buck LED circuit 12 and outputs a driving signal of the buck LED circuit.
Specifically, the circuit structure and the working principle of the switch buck LED constant current control circuit 11 are the same as those of the switch buck LED constant current control circuit in the first embodiment or the second embodiment, and are not described in detail herein.
As shown in fig. 8, the step-down LED circuit 12 obtains a stable output based on the control of the switching step-down LED constant current control circuit 11.
Specifically, the step-down LED circuit 12 includes an LED light emitting module 121, an inductor L, a freewheeling diode D, a power switching tube Q, and a sampling module 122. The positive electrode of the LED light emitting module 121 is connected with an input power Vin, and the negative electrode is connected with one end of the inductor L. The other end of the inductor L is connected with the anode of the freewheeling diode D. The negative electrode of the freewheel diode D is connected with the input power supply Vin. In this embodiment, the power switch Q is an NMOS, the drain electrode of the power switch Q is connected to the positive electrode of the freewheeling diode D, the source electrode of the power switch Q is connected to the sampling module 122 and then grounded, and the gate electrode of the power switch Q is connected to the driving signal Drv; in practical use, the connection relationship between the ports of the power switch Q is related to the type of the power switch Q, which is not limited by the embodiment. The connection node between the power switch Q and the sampling module 122 outputs the current detection sampling signal Vcs, and in this embodiment, the sampling module 122 is implemented by using a sampling resistor.
Example IV
As shown in fig. 9 to 12, this embodiment provides a switching buck LED constant current control method, in this embodiment, the switching buck LED constant current control system 1 described in the third embodiment is used to describe the switching buck LED constant current control method of the present invention, and in practical use, any hardware circuit or software code according to the switching buck LED constant current control method of the present invention is applicable, and is not limited to the list of this embodiment. The switch buck LED constant current control method comprises the following steps:
monitoring the current detection sampling signal Vcs of the step-down LED circuit 12, outputting a valid On signal On in a period of time when the current detection sampling signal Vcs rises to the first time when the current detection sampling signal Vcs exceeds the average reference Vref1 and in a period of time when the current detection sampling signal Vcs exceeds the average reference Vref1, and then disabling the On signal On, wherein if the current detection sampling signal Vcs is greater than the peak reference Vref2, the On signal On is disabled;
reducing a turn-Off reference signal ref_off when the current detection sampling signal Vcs is greater than the peak reference Vref2, increasing the turn-Off reference signal ref_off when the current detection sampling signal Vcs is less than the peak reference Vref2, comparing a preset charging signal RC with the turn-Off reference signal ref_off, and generating the turn-Off end signal Off when the preset charging signal RC is greater than the turn-Off reference signal ref_off;
And adjusting a driving signal Drv of the power switch tube Q based On the On signal On and the Off end signal Off so as to realize constant current output and control ripple of output current.
Specifically, in the initial state, as shown in fig. 9, the power switch Q is turned On, the On signal On is at a high level (active), the current detection sampling signal Vcs is smaller than the average reference Vref1, and at this time, the adder 114a2 starts to operate and starts to count slowly from 0. The current detection sampling signal Vcs gradually increases as the inductance L is charged. When the current detection sampling signal Vcs reaches the average reference Vref1, the first comparison result Cp1 outputs a high level, the adder 114a2 stops working, the count result is n, and the product of the count result n and the basic clock generated by the oscillator 114a1 is the first time Δt; at the same time, the subtractor 114a3 starts to operate, and the subtractor 114a3 performs subtraction on the count result n. In the initial stage, since the current detection sampling signal Vcs rises faster, when the subtractor 114a3 does not count zero (the subtraction time is less than the first time Δt), the current detection sampling signal Vcs is already greater than the peak reference Vref2, at this time, the second comparison result Cp2 outputs a high level, the On signal On jumps to a low level (fails), the On signal On controls the power switch Q to be turned On when the On signal On is high, and the On signal On controls the power switch Q to be turned off when the On signal On is low. With the adjustment of a plurality of periods, the rising speed of the current detection sampling signal Vcs is reduced, the time for performing subtraction approaches to the first time Δt until reaching equilibrium, at this time, since the current detection sampling signal Vcs is always smaller than the peak reference Vref2, the subtractor 114a3 slowly counts back to 0 from the count result n, and then the On signal On jumps to a low level, and the count result n of the subtractor 114a3 multiplied by the basic clock is Δt. The current detection sampling signal Vcs is equal to the vertical deviation value of the average reference Vref1, so that the average current value of the output current i_led is: iaverage=vref 1/Rcs, where Rcs is the resistance of the sampling module 122.
Specifically, when the On signal On is at a low level, the adaptive clock generating module 113 starts to operate, and generates a corresponding Off end signal Off. As shown in fig. 10, if it is detected that the second comparison result Cp2 outputs a high level (there is a high level pulse output) in one PWM period, the inverted logic signal LS of the second comparison result Cp2 is a low level pulse, when the driving signal Drv transitions to a low level, the pulse signal pulse (in this embodiment, the reference value is set to 300 ns) arrives, the pull-Down control signal Down transitions to a high level, the pull-Down transistor MN is controlled to be turned on, the Off reference signal ref_off is discharged to decrease, and the Off reference signal ref_off remains until the pull-Down control signal Down transitions to a low level. As shown in fig. 11, if the second comparison result Cp2 is not detected (no high level pulse is output) in one PWM period, the inversion logic signal LS of the second comparison result Cp2 is always kept at a high level, when the driving signal Drv transitions to a low level, the pulse signal pulse arrives, the pull-Up control signal Up transitions to a low level, the pull-Up tube MP is controlled to be turned on, the Off reference signal ref_off is charged to be increased, and the Off reference signal ref_off is maintained until the pull-Up control signal Up transitions to a high level. Comparing the preset charging signal RC with the Off reference signal ref_off, wherein the preset charging signal RC is a triangular wave signal, when the On signal On is invalid, the preset charging signal RC gradually increases, and when the preset charging signal RC is greater than the Off reference signal ref_off, the Off end signal Off is valid, so as to control the power switch tube Q to be turned back On. As shown in fig. 12, after the power supply VDD is powered up, the first switch S1 is turned on, the bias voltage Vbias provides an initial potential (in this embodiment, the reference value is 3V) to the Off reference signal ref_off, and then the first switch S1 is turned Off. At this time, the Off reference signal ref_off has a higher potential, the Off (low level) time Toff in the driving signal Drv is longer, the on (high level) time Ton in the driving signal Drv is also longer, the charging current of the inductor L rises quickly, the peak current comparing module 112 is triggered to generate a high level pulse, the pull-Down control signal Down pulls Down the Off reference signal ref_off, and the Off reference signal ref_off gradually falls; when the output current i_led tends to be stable, the output of the peak current comparing module 112 does not generate a high level, so as to avoid the drop of the Off reference signal ref_off caused by the discharge of the first charging capacitor C1, and the pull-Up control signal Up will pull Up the Off reference signal ref_off at this time, so as to ensure that the Off reference signal ref_off is always stable at a constant value. In the self-adaptive adjustment process, the period of the turn-Off ending signal Off gradually becomes smaller, the fixed discharge time Toff is finally realized, and the inductance precision and the ripple are optimized.
The current detection sampling signal Vcs and the peak reference Vref2 are sent to the input terminal of the peak current comparing module 112, the peak current comparing module 112 outputs to the PWM logic control module 114, and the current detection sampling signal Vcs and the average reference voltage Vref1 are also sent to the input terminal of the average current comparing module 111, and the average current comparing module 111 outputs to the PWM logic control module 114, and the On signal On is generated by the count control. When the On signal On is high, the driving signal Drv is high, and the external power switch tube Q is turned On; when the On signal On is low, the driving signal Drv is low, the external power switch Q is turned Off, and the adaptive clock generating module 113 is enabled, and the adaptive clock generating module 113 outputs and generates a corresponding Off end signal Off, and the On signal On and the Off end signal Off are added together to realize a PWM period.
As an implementation manner of the present invention, the switch buck LED constant current control method further includes: and monitoring the current detection sampling signal Vcs, and turning off the power switch tube Q when the current detection sampling signal Vcs is larger than a short-circuit protection reference Vref3, wherein the short-circuit protection reference Vref3 is larger than the peak value reference Vref2.
As another implementation manner of the present invention, the switching buck LED constant current control method further includes: the values of the average reference Vref1 and the peak reference Vref2 are adjusted based on a dimming control signal DIM to achieve dimming control.
As shown in fig. 13, which is an input-output timing diagram of the switch buck LED constant current control circuit, system and method of the present invention, it can be seen that after the power supply VDD is powered on, the constant current control circuit is self-adaptively adjusted, and the current is transited from the discontinuous conduction mode to the continuous conduction mode, so as to achieve high precision and small ripple of the output current i_led on the LED light emitting unit. Amplifying fig. 13, the waveform of the output current i_led in the discontinuous conduction mode before stabilizing is as shown in fig. 14, the average reference Vref 1=200 mV is set, the time of the adder and the subtractor before stabilizing is consistent, the output of the peak current comparing module is detected when the subtractor works, the On signal On is changed to the logic low level in advance, and the driving signal Drv is turned off to enter the inductor discharging stage. Amplifying fig. 13, the waveform of the output current i_led in the continuous conduction mode after stabilization is as shown in fig. 15, and the adder and the subtractor are consistent in time after stabilization, and the current detection sampling signal Vcs is equal to the up-down deviation value of the average reference Vref1 (200 mV), so that the high precision and the small ripple of the output current are finally realized.
In summary, the invention provides a switch buck type LED constant current control circuit, a system and a method, comprising: the device comprises an average current comparison module, a peak current comparison module, a self-adaptive clock generation module, a PWM logic control module and a driving module; the average current comparison module receives a current detection sampling signal of the buck LED circuit and is used for comparing the current detection sampling signal with an average reference and obtaining a first comparison result; the peak current comparison module receives the current detection sampling signal, and is used for comparing the current detection sampling signal with a peak reference and obtaining a second comparison result; the average reference is less than the peak reference; the self-adaptive clock generation module receives the inverse logic signal of the second comparison result to adjust the level of the turn-off reference signal and generates a corresponding turn-off ending signal; the PWM logic control module is connected with the output ends of the average current comparison module, the peak current comparison module and the self-adaptive clock generation module, adjusts the on time of a logic control signal based on the first comparison result and the second comparison result, and adjusts the off time of the logic control signal based on the off end signal so as to realize constant current output of the step-down LED circuit and reduce output current ripple of the step-down LED circuit; the driving module is connected to the output end of the PWM logic control module, and drives a power switching tube in the step-down LED circuit to be turned on or off based on the logic control signal. Monitoring a current detection sampling signal of a buck LED circuit, outputting a valid conduction signal in a period in a first time when the current detection sampling signal rises to the average reference and a first time when the current detection sampling signal exceeds the average reference, and then enabling the conduction signal to fail; if the current detection sampling signal is greater than the peak reference, the conduction signal fails in advance when the current detection sampling signal is greater than the peak reference; decreasing the off reference signal when the current detection sampling signal is greater than the peak reference, and increasing the off reference signal when the current detection sampling signal is less than the peak reference; comparing a preset charging signal with the turn-off reference signal, and generating the turn-off ending signal when the preset charging signal is greater than the turn-off reference signal; and adjusting a driving signal of the power switch tube based on the on signal and the off ending signal so as to realize constant current output and control ripple of output current. The switching buck LED constant current control circuit, the switching buck LED constant current control system and the switching buck LED constant current control method automatically adjust PWM clock period through the internal circuit, control on time through the counter, and finally realize smaller current ripple and high precision of output current by adopting a constant current control mode of average current detection and peak current detection, and have better linear adjustment rate and load adjustment rate; the self-adaptive adjustment is adopted, so that small LED output current can be realized, and the self-adaptive LED power supply can be widely applied to the field of electronic circuits. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.
Claims (11)
1. The switching buck type LED constant current control circuit is characterized by at least comprising:
the device comprises an average current comparison module, a peak current comparison module, a self-adaptive clock generation module, a PWM logic control module and a driving module;
the average current comparison module receives a current detection sampling signal of the buck LED circuit and is used for comparing the current detection sampling signal with an average reference and obtaining a first comparison result;
the peak current comparison module receives the current detection sampling signal, and is used for comparing the current detection sampling signal with a peak reference and obtaining a second comparison result; the average reference is less than the peak reference;
The self-adaptive clock generation module adjusts the level of the turn-off reference signal based on the inverse logic signal of the second comparison result and generates a corresponding turn-off ending signal; the self-adaptive clock generation module comprises a turn-off reference signal control unit and a turn-off ending signal generation unit; the turn-off reference signal control unit receives an inverted logic signal of the second comparison result, and generates a pull-down control signal when the current detection sampling signal is greater than the peak reference; generating a pull-up control signal when the current sense sampling signal is less than the peak reference; the turn-off end signal generating unit receives the pull-down control signal and the pull-up control signal to adjust the level of a turn-off reference signal, the pull-down control signal controls the turn-off reference signal to decrease the level, and the pull-up control signal controls the turn-off reference signal to increase the level; meanwhile, comparing a preset charging signal with the turn-off reference signal, and generating the turn-off ending signal when the preset charging signal is larger than the turn-off reference signal;
the PWM logic control module is connected with the output ends of the average current comparison module, the peak current comparison module and the self-adaptive clock generation module, adjusts the on time of a logic control signal based on the first comparison result and the second comparison result, and adjusts the off time of the logic control signal based on the off end signal so as to realize constant current output of the step-down LED circuit and reduce output current ripple; the PWM logic control module comprises a conduction signal generation unit and a logic control signal generation unit; the conducting signal generating unit receives the first comparison result and the second comparison result, outputs an effective conducting signal in the first time when the current detection sampling signal rises to the average reference and the first time when the current detection sampling signal exceeds the average reference, and directly fails if the current detection sampling signal is greater than the peak reference; the logic control signal generating unit is connected with the output ends of the conducting signal generating unit and the adaptive clock generating module and generates the logic control signal based on the conducting signal and the turn-off ending signal;
The driving module is connected to the output end of the PWM logic control module and drives a power switching tube in the step-down LED circuit to be turned on or off based on the logic control signal; and when the turn-on signal is effective, controlling the power switch tube to be turned on, when the turn-on signal is ineffective, controlling the power switch tube to be turned off, and when the turn-off ending signal is effective, controlling the power switch tube to be turned on again.
2. The switching buck LED constant current control circuit of claim 1, wherein: the turn-off reference signal control unit comprises a first inverter, a first NAND gate, a second NAND gate, a third NAND gate, a fourth NAND gate and a second inverter;
the input end of the first NAND gate is respectively connected with the inverted logic signal of the second comparison result and the output end of the second NAND gate; the input end of the first inverter receives an inversion logic signal of the second comparison result; the input end of the second NAND gate is respectively connected with the output end of the first inverter and the output end of the first NAND gate; the input end of the third NAND gate is respectively connected with the output end of the first NAND gate and a pulse signal, the input end of the second inverter is connected with the output end of the third NAND gate, and the output end outputs the pull-down control signal; and the input end of the fourth NAND gate is respectively connected with the output end of the second NAND gate and the pulse signal, and the output end outputs the pull-up control signal.
3. The switching buck LED constant current control circuit of claim 1, wherein: the turn-off ending signal generating unit comprises a first current source, a pull-up tube, a pull-down tube, a second current source, a first charging capacitor, a first switch, a third current source, a second charging capacitor and a comparator;
the first current source, the pull-up tube, the pull-down tube and the second current source are sequentially connected in series between a power supply and the ground, a connection node of the pull-up tube and the pull-down tube outputs the turn-off reference signal, a control end of the pull-up tube is connected with the pull-up control signal, and a control end of the pull-down tube is connected with the pull-down control signal; one end of the first charging capacitor is connected with the turn-off reference signal, and the other end of the first charging capacitor is grounded; one end of the first switch is connected with the turn-off reference signal, and the other end of the first switch is grounded after being connected with the bias voltage;
one end of the third current source is connected with a power supply, and the other end of the third current source is connected with the second charging capacitor; the other end of the second charging capacitor is grounded; the connection node of the third current source and the second charging capacitor outputs the preset charging signal; and the input end of the comparator is respectively connected with the turn-off reference signal and the preset charging signal, and outputs the turn-off ending signal.
4. The switching buck LED constant current control circuit of claim 1, wherein: the conduction signal generation unit comprises an oscillator, an adder and a subtracter;
the adder is connected with the output ends of the oscillator and the average current comparison module, and performs addition operation when the current detection sampling signal rises to the average reference to obtain a counting result corresponding to the first time;
the subtracter is connected with the output ends of the oscillator, the adder and the peak current comparison module, and is used for subtracting the counting result of the adder, and if the current detection sampling signal is smaller than the peak reference, the conducting signal is controlled to be invalid when the subtraction result is zero; and if the current detection sampling signal is larger than the peak value reference, directly controlling the conduction signal to fail.
5. The switching buck LED constant current control circuit of claim 1, wherein: the switch buck LED constant current control circuit further comprises a short circuit protection module and/or a dimming module; the short-circuit protection module receives the current detection sampling signal, compares the current detection sampling signal with a short-circuit protection reference, and turns off the power switch tube when the current detection sampling signal is larger than the short-circuit protection reference, wherein the short-circuit protection reference is larger than the peak value reference; the dimming module receives a dimming control signal and adjusts values of the average reference and the peak reference based on the dimming control signal.
6. The switching buck type LED constant current control system is characterized by at least comprising:
the switching buck LED constant current control circuit and buck LED circuit according to any one of claims 1 to 5, wherein the switching buck LED constant current control circuit receives a current detection sampling signal of the buck LED circuit and outputs a driving signal of the buck LED circuit.
7. The switch buck LED constant current control system of claim 6, wherein: the step-down type LED circuit comprises an LED light-emitting module, an inductor, a freewheeling diode, a power switch tube and a sampling module;
the positive electrode of the LED light-emitting module is connected with an input power supply, and the negative electrode of the LED light-emitting module is connected with one end of the inductor; the other end of the inductor is connected with the anode of the freewheeling diode; the negative electrode of the freewheel diode is connected with the input power supply; one end of the power switch tube is connected with the positive electrode of the freewheeling diode, the other end of the power switch tube is connected with the sampling module and then grounded, and the control end of the power switch tube is connected with the driving signal; and a connecting node of the power switch tube and the sampling module outputs the current detection sampling signal.
8. The switching buck type LED constant current control method is characterized by at least comprising the following steps:
monitoring a current detection sampling signal of a buck LED circuit, outputting a valid conduction signal in a period in a first time when the current detection sampling signal rises to an average reference and a first time when the current detection sampling signal exceeds the average reference, and then enabling the conduction signal to fail; if the current detection sampling signal is larger than the peak value reference, the conduction signal is invalid;
reducing a turn-off reference signal when the current detection sampling signal is greater than the peak reference, increasing the turn-off reference signal when the current detection sampling signal is less than the peak reference, comparing a preset charging signal with the turn-off reference signal, and generating the turn-off end signal when the preset charging signal is greater than the turn-off reference signal;
adjusting a driving signal of the power switch tube based on the conducting signal and the turn-off ending signal, controlling the power switch tube in the step-down LED circuit to be conducted when the conducting signal is effective, controlling the power switch tube to be turned off when the conducting signal is ineffective, and controlling the power switch tube to be turned on again when the turn-off ending signal is effective; to realize constant current output and control ripple of output current;
Wherein the average reference is less than the peak reference.
9. The switching buck LED constant current control method of claim 8, wherein: the method for obtaining the conduction signal comprises the following steps:
when the current detection sampling signal rises to the average reference, adding operation is carried out, and a counting result corresponding to the first time is obtained;
subtracting the counting result, and if the current detection sampling signal is smaller than the peak value reference, controlling the conducting signal to fail when the subtracting operation result is zero; and if the current detection sampling signal is larger than the peak value reference, directly controlling the conduction signal to fail.
10. The switching buck LED constant current control method of claim 8, wherein: the switch buck LED constant current control method further comprises the following steps: and monitoring the current detection sampling signal, and turning off the power switch tube when the current detection sampling signal is larger than a short-circuit protection reference, wherein the short-circuit protection reference is larger than the peak value reference.
11. The switching buck LED constant current control method of claim 8, wherein: the switch buck LED constant current control method further comprises the following steps: and adjusting the values of the average reference and the peak reference based on a dimming control signal to realize dimming control.
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Denomination of invention: Switch buck LED constant current control circuit, system, and method Effective date of registration: 20231008 Granted publication date: 20230505 Pledgee: Bank of China Limited Wuxi Branch Pledgor: China Resources micro integrated circuit (Wuxi) Co.,Ltd. Registration number: Y2023980060027 |
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