CN211184343U

CN211184343U - L ED driver

Info

Publication number: CN211184343U
Application number: CN201921911101.9U
Authority: CN
Inventors: 毛昭祺; 王纪周; 柯乃泉
Original assignee: Hangzhou Upowertek Power Supply Co ltd
Current assignee: Hangzhou Upowertek Power Supply Co ltd
Priority date: 2019-11-07
Filing date: 2019-11-07
Publication date: 2020-08-04
Anticipated expiration: 2029-11-07

Abstract

The utility model discloses an L ED driver, including the PFC main circuit, drive control circuit, an isolation circuit, voltage regulation circuit, frequency control drive circuit, current regulation circuit and resonance DC-DC circuit, the PFC main circuit is connected with resonance DC-DC circuit, resonance DC-DC circuit is connected with current regulation circuit's input and voltage regulation circuit's input respectively, current regulation circuit's output is connected with frequency control drive circuit's input, frequency control drive circuit's output and resonance DC-DC circuit are connected, voltage regulation circuit's output is connected with drive control circuit's input through isolation circuit, drive control circuit's output and PFC main circuit are connected, the utility model discloses a two secondary windings of transformer and the different coupling coefficient of primary winding, realize L ED driver's multichannel output, realize through voltage regulation circuit and current regulation circuit that there is both constant voltage output and constant current output in a L ED's the multichannel output.

Description

L ED driver

Technical Field

The utility model relates to a lighting apparatus technical field especially relates to an L ED driver.

Background

L ED is widely used in the field of lighting because of its advantages of energy saving, environmental protection, long life, high conversion efficiency, etc. L ED driver converts input voltage into direct current and supplies L ED load, the current L ED driver has two types, one is L ED driver outputting constant current, the other is L ED driver outputting constant voltage.

For example, a constant voltage and constant current driver of a high power L ED spotlight disclosed in chinese patent document, whose publication number CN201467519U, publication date 2010, 05 month and 12 months, comprises a power input terminal, a rectifying circuit connected to the power input terminal, a switching transformer connected to the rectifying circuit, and an output terminal connected to the switching transformer and used for connecting a load L ED, and is characterized by further comprising a PFC circuit, a power driving constant voltage circuit and a constant current circuit, the PFC circuit being disposed between the rectifying circuit and the switching transformer, the power driving constant voltage circuit comprising a power driving circuit and a constant voltage control circuit, the power driving circuit being disposed between the PFC circuit and the switching transformer, the constant voltage control circuit acquiring an output signal of the switching transformer and generating a feedback signal to the power driving circuit, the constant current circuit being disposed between the switching transformer and the output terminal, the constant current output of the L ED driver being realized by the constant current circuit and the constant voltage current, but the L ED driver of the present invention still can only realize either constant current or constant voltage output, and cannot realize both constant voltage output in multiple outputs of the same driver.

Disclosure of Invention

The utility model discloses mainly solve the problem that current technique L ED driver can't realize same driver and export constant voltage and constant current simultaneously, provide a L ED driver, through constant voltage and constant current detection regulation and control, make existing constant current output also have the constant voltage output in the multiplexed output of same driver.

An L ED driver, including PFC main circuit, drive control circuit, isolation circuit, voltage regulation circuit, frequency control drive circuit, current regulation circuit and resonance DC-DC circuit, the input of PFC main circuit is regarded as the input of L ED driver and is used for connecting the power, the output of PFC main circuit with the input of resonance DC-DC circuit is connected, the output of resonance DC-DC circuit includes constant voltage output and constant current output, the input of current regulation circuit with the constant current output, the output of current regulation circuit with the frequency control drive circuit is connected, current regulation circuit is used for detecting the electric current that the constant current output is and outputting first feedback signal for resonance DC-DC circuit, frequency control drive circuit according to the size of first feedback signal output first drive signal for resonance DC-DC circuit, through the operating frequency of resonance DC-DC circuit with the electric current output of constant current output is kept constant, the input of voltage regulation circuit with the input of constant voltage regulation circuit is connected, the constant voltage regulation circuit with the resonance DC-DC circuit through constant voltage detection output, the constant voltage detection circuit and constant voltage detection output, the constant voltage regulation circuit is connected to the resonance DC-DC output through constant voltage detection circuit, the constant voltage detection output.

Preferably, the main PFC circuit includes an inductor L, a switching tube S0, a diode D1 and a capacitor C0, one end of the inductor L is connected to a positive terminal of a power supply, the other end of the inductor L is connected to one end of the switching tube S0 and an anode of the diode D1, the other end of the switching tube S0 is connected to one end of the capacitor C0 and a negative terminal of the power supply, the other end of the capacitor C0 is connected to a cathode of the diode D1, two ends of the capacitor C0 are also connected to the resonant DC-DC circuit as an output end of the main PFC circuit, a current passes through the inductor L to prevent a high voltage interference signal from damaging the circuit, a voltage stored at two ends of the capacitor C0 is controlled by the switching tube S0 to control and regulate an output voltage Vbus of the main PFC circuit, and the diode D1 prevents the current from flowing back into the switching tube S0.

Preferably, the resonant DC-DC circuit further includes a switching unit, a resonant capacitor Cr and a transformer, the transformer includes a primary winding N1, a secondary winding M1 and a secondary winding M2, the primary winding N1 and the resonant capacitor Cr are connected in series and then connected to the switching unit, and the other two ends of the switching unit are used as input ends of the resonant DC-DC circuit; the secondary winding M1 is used as a constant voltage output end through a first rectified output end after rectification, and the secondary winding M2 is used as a constant current output end through a second rectified output end after rectification. The secondary winding M1 and the secondary winding M2 are transformed by a transformer, so that the circuit generates two paths of output.

Preferably, the coupling coefficient between the secondary winding M1 and the primary winding N1 is greater than the coupling coefficient between the secondary winding M2 and the primary winding N1. According to different coupling coefficients of the secondary winding M1, the secondary winding M2 and the primary winding N1, the resonant DC-DC circuit generates multiple paths of different outputs.

Preferably, the switching unit in the resonant DC-DC circuit includes a switching tube S1 and a switching tube S2, the resonant DC-DC circuit further includes a diode D2, a capacitor C2 and a resistor Rs, a first end of the switching tube S2 is used as an input positive terminal of the resonant DC-DC circuit, a second end of the switching tube S2 is connected to a first end of the switching tube S2 and one end of a primary winding N2 respectively, a second end of the switching tube S2 is used as an input negative terminal of the resonant DC-DC circuit and is connected to one end of the resonant capacitor Cr, the other end of the resonant capacitor Cr is connected to the other end of the primary winding N2, the secondary winding M2 and the secondary winding M2 have tapping terminals, the first end of the secondary winding M2 is connected to an anode of the diode D2, the secondary winding M2 is connected to an output terminal of a secondary winding M2, a rectifying diode D2, a diode D2 is connected to a diode D2, a diode C2 is connected to a diode D2, a diode C2 is connected to a diode C-C2, a diode C2, a secondary winding M is connected to a diode C-C diode C2, a diode C diode is connected to a diode C is connected to a diode C for rectifying diode C for rectifying a diode C for rectifying a diode C for rectifying a constant-DC output, a rectifying diode C, a diode C rectifying diode C for rectifying a rectifying diode C for rectifying diode C for rectifying a diode C for rectifying a DC output, a diode.

Preferably, the voltage regulation circuit includes an operational amplifier U1, a resistor R1, a resistor R2, a resistor R3, and a capacitor C4, wherein a negative phase input terminal of the operational amplifier U1 is connected to a first terminal of the capacitor C4, a first terminal of the resistor R1, and a first terminal of the resistor R2, another terminal of the resistor R1 is connected to a first terminal of the capacitor C1, another terminal of the resistor R2 is connected to a second terminal of the capacitor C1, a second terminal of the capacitor C4 is connected to an output terminal of the operational amplifier U1 via the resistor R3, and a positive phase input terminal of the operational amplifier U1 receives the voltage reference signal Vref. The operational amplifier U1 compares the detected voltage signal with the voltage reference signal Vref, outputs a second feedback signal to the drive control circuit through the isolation circuit according to the comparison result, and the capacitor C1, the resistor R3 and the operational amplifier form negative feedback regulation.

Preferably, the isolation circuit comprises a photoelectric coupler, an input end of the photoelectric coupler is connected with the voltage regulating circuit, and an output end of the photoelectric coupler is connected with the driving control circuit. The voltage regulating circuit and the drive control circuit are isolated through the photoelectric coupler, and the interference of high-frequency signals to the circuit is prevented.

Preferably, the current regulation circuit comprises an operational amplifier U2, a capacitor C5 and a resistor R4, wherein a negative phase input terminal of the operational amplifier U2 is connected to a first terminal of the capacitor C5 and a second terminal of the resistor Rs, respectively, a second terminal of the capacitor C5 is connected to an output terminal of the operational amplifier U2 through a resistor R4, and a positive phase input terminal of the operational amplifier inputs the current reference signal Iref. The operational amplifier U2 compares the detected current signal with the current reference signal Iref, and outputs a first feedback signal to the frequency control driving circuit according to the comparison result, and the operational amplifier U2, the capacitor C5 and the resistor R4 form negative feedback regulation.

Preferably, the frequency control driving circuit includes a resonant control chip, a voltage-controlled oscillator and a driving circuit, the voltage-controlled oscillator receives the first feedback signal transmitted by the current regulating circuit, determines the frequency of the switching tube S1 and the switching tube S2 according to the magnitude of the first feedback signal, transmits the frequency signal to the resonant control chip, and the resonant control chip generates a driving signal according to the frequency signal through the driving circuit and outputs the driving signal to the switching tube S1 and the switching tube S2. The resonance control chip receives a first feedback signal output by the current regulating circuit, and controls the conduction and the cut-off of the MOS tube Q1 and the MOS tube Q2 according to the first feedback signal, so that the current output of the resonance DC-DC circuit is stable and the current reference signal Iref is ensured, and the circuit is ensured to realize constant current output.

Preferably, the driving control circuit includes a PFC control chip, a third operational amplifier, a fourth operational amplifier and an RS flip-flop, a second feedback signal transmitted by the voltage regulating circuit is input to a positive phase input terminal of the third operational amplifier and a negative phase input terminal of the fourth operational amplifier, a second voltage reference signal is input to a negative phase input terminal of the third operational amplifier, an output terminal of the third operational amplifier is connected to an S terminal of the RS flip-flop, a third voltage reference signal is input to a positive phase input terminal of the fourth operational amplifier, an output terminal of the fourth operational amplifier is connected to an R terminal of the RS flip-flop, a Q terminal and a Q terminal of the RS flip-flop are both connected to the PFC control chip, and the PFC control chip is connected to the switching tube S0. The PFC control chip controls the switch tube S0 according to the output result of the RS trigger, so that the output voltage of the PFC main circuit is stabilized at a voltage reference signal Vref, and the constant voltage output of the circuit is realized.

The beneficial effects of the utility model are that (1) through two different coupling coefficients of secondary winding and primary winding of transformer, realize L ED driver's multiplexed output, (2) through voltage regulating circuit to the detection of voltage and drive control circuit's regulation, realize L ED driver's constant voltage output, (3) through current regulating circuit to the detection of electric current and frequency control drive circuit's regulation, realize L ED driver's constant current output.

Drawings

Fig. 1 is a structural schematic diagram of an L ED driver according to the first embodiment.

Fig. 2 is a circuit schematic diagram of an L ED driver of the first embodiment.

Fig. 3 is a schematic diagram of a voltage regulating circuit according to a first embodiment.

Fig. 4 is a schematic diagram of a current regulating circuit according to the first embodiment.

In the figure, 1, a power supply, 2, a PFC main circuit, 3, a resonant DC-DC circuit, 4, a current regulating circuit, 5, a voltage regulating circuit, 6, a frequency control driving circuit, 7, an isolation circuit and 8, a driving control circuit.

Detailed Description

The technical solution of the present invention is further specifically described below by way of examples and with reference to the accompanying drawings.

An L ED driver, as shown in FIG. 1, includes a PFC main circuit 2, a driving control circuit 8, an isolation circuit 7, a voltage regulation circuit 5, a frequency control driving circuit 6, a current regulation circuit 4 and a resonant DC-DC circuit 3, wherein an input terminal of the PFC main circuit 2 is used as an input terminal of the L ED driver and is used for connecting a power supply 1, an output terminal of the PFC main circuit 2 is connected with an input terminal of the resonant DC-DC circuit 3, an output terminal of the resonant DC-DC circuit 3 includes a constant voltage output terminal and a constant current output terminal, an input terminal of the current regulation circuit 4 is connected with the constant current output terminal of the resonant DC-DC circuit 3, an output terminal of the current regulation circuit 4 is connected with the frequency control driving circuit 6, the current regulation circuit 4 is used for detecting a current output from the constant current output terminal and outputting a first feedback signal to the frequency control driving circuit 6, the frequency control driving circuit 6 outputs a first driving signal to the resonant DC-DC circuit 3 according to the magnitude of the first feedback signal, the constant current output from the output terminal is maintained by the resonant DC-DC circuit 3 through the operating frequency of the resonant DC-DC circuit 3, an input terminal of the voltage regulation circuit 5 is connected with the constant voltage regulation circuit 5, and is connected with the constant voltage control driving circuit 8 through the constant voltage output terminal of the constant voltage control driving circuit 5, and is connected with the constant voltage control output terminal of the constant voltage control driving circuit 2 and is connected with the constant voltage control output terminal of.

As shown in fig. 2, the main PFC circuit 2 includes an inductor L, a switching tube S0, a diode D1, and a capacitor C0, wherein one end of the inductor L is connected to the positive electrode of the power supply 1, the other end of the inductor L is connected to one end of the switching tube S0 and the anode of the diode D1, the other end of the switching tube S0 is connected to one end of a capacitor C0 and the negative electrode of the power supply 1, the other end of the capacitor C0 is connected to the cathode of the diode D1, and the two ends of the capacitor C0 are connected to the resonant DC-DC circuit 3 as the output end of the main PFC circuit 2.

The resonant DC-DC circuit 3 comprises a switch unit, a resonant capacitor Cr, a transformer, a diode D2, a diode D3, a diode D4, a diode D5, a capacitor C1, a capacitor C2 and a resistor Rs, wherein the transformer comprises a primary winding N1, a secondary winding M1 and a secondary winding M2, the primary winding N1 and the resonant capacitor Cr are connected in series and then connected with the switch unit, and the other two ends of the switch unit are used as input ends of the resonant DC-DC circuit; the secondary winding M1 is used as a constant voltage output end through a first rectified output end after rectification, the secondary winding M2 is used as a constant current output end through a second rectified output end after rectification, the coupling coefficient of the secondary winding M1 and the primary winding N1 is larger than that of the secondary winding M2 and the primary winding N1, the switching unit comprises a switching tube S1 and a switching tube S2, the first end of the switching tube S1 is used as the input positive end of the resonant DC-DC circuit, the second end of the switching tube S1 is respectively connected with the first end of the switching tube S2 and one end of the primary winding N1, the second end of the switching tube S2 is used as the input negative end of the resonant DC-DC circuit and is connected with one end of a resonant capacitor Cr, the other end of the resonant capacitor Cr is connected with the other end of the primary winding N1, the secondary winding M1 and the secondary winding M2 are provided with tapped ends, the first end of the secondary winding M1 is connected with the anode of the diode D2, the second end of the secondary winding M1 is connected with the cathode of a diode D2 through a diode D3, the cathode of the diode D2 and the tapping end of the secondary winding M1 are connected with a capacitor C1, and two ends of a capacitor C1 are used as constant-voltage output ends; the first end of the secondary winding M2 is connected with the anode of the diode D4, the second end of the secondary winding M2 is connected with the cathode of the diode D4 through the diode D5, the cathode of the diode D4 is connected with the first end of the capacitor C2, the tapping end of the secondary winding M2 is respectively connected with the second end of the capacitor C2 and the first end of the resistor Rs, two ends of the capacitor C2 serve as constant current output ends, and the second end of the resistor Rs is connected with the current regulating circuit 4.

The isolation circuit 7 comprises a photoelectric coupler, the input end of the photoelectric coupler is connected with the voltage regulating circuit 5, and the output end of the photoelectric coupler is connected with the drive control circuit 8.

The frequency control driving circuit 6 comprises a resonance control chip, a voltage-controlled oscillator and a driving circuit, the voltage-controlled oscillator receives the first feedback signal transmitted by the current regulating circuit 4, determines the frequency of the switching tube S1 and the switching tube S2 according to the first feedback signal, transmits the frequency signal to the resonance control chip, and the resonance control chip generates a driving signal through the driving circuit according to the frequency signal and outputs the driving signal to the switching tube S1 and the switching tube S2.

The driving control circuit 8 includes a PFC control chip, a third operational amplifier, a fourth operational amplifier and an RS flip-flop, a second feedback signal transmitted by the voltage regulating circuit 5 is input to a positive phase input terminal of the third operational amplifier and a negative phase input terminal of the fourth operational amplifier, a second voltage reference signal is input to a negative phase input terminal of the third operational amplifier, an output terminal of the third operational amplifier is connected to an S terminal of the RS flip-flop, a third voltage reference signal is input to a positive phase input terminal of the fourth operational amplifier, an output terminal of the fourth operational amplifier is connected to an R terminal of the RS flip-flop, a Q terminal and a Q terminal of the RS flip-flop are both connected to the PFC control chip, and the PFC control chip is connected to the switching tube S0.

As shown in fig. 3, the voltage regulating circuit 5 includes an operational amplifier U1, a resistor R1, a resistor R2, a resistor R3, and a capacitor C4, wherein a negative phase input terminal of the operational amplifier U1 is connected to a first terminal of a capacitor C4, one terminal of a resistor R1, and one terminal of a resistor R2, another terminal of a resistor R1 is connected to a first terminal of a capacitor C1, another terminal of a resistor R2 is connected to a second terminal of a capacitor C1, a second terminal of a capacitor C4 is connected to an output terminal of the operational amplifier U1 via a resistor R3, and a positive phase input terminal of the operational amplifier U1 receives a voltage reference signal Vref.

As shown in fig. 4, the current regulating circuit 4 includes an operational amplifier U2, a capacitor C5, and a resistor R4, wherein a negative phase input terminal of the operational amplifier U2 is connected to a first terminal of the capacitor C5 and a second terminal of the resistor Rs, respectively, a second terminal of the capacitor C5 is connected to an output terminal of the operational amplifier U2 through a resistor R4, and a positive phase input terminal of the operational amplifier inputs the current reference signal Iref.

In the specific application, 220V alternating current enters a PFC main circuit 2 through a power supply 1 after being rectified by a rectifying circuit, the amplitude of input voltage of the PFC main circuit 2 is changed in a sinusoidal mode, an inductor L, a switching tube S0 and a diode D1 form a Boost circuit, under the control of a driving control circuit, the input current of the Boost circuit is close to input voltage, namely close to a sinusoidal wave, the PFC function is achieved, the PFC main circuit 2 achieved by the Boost circuit outputs direct current voltage Vbus under the control of a voltage adjusting circuit 5 and a driving control circuit 8, the direct current voltage Vbus with relatively stable amplitude is input into a resonant DC-DC circuit 3, the switching tube S1, a switching tube S2, a resonant capacitor Cr, a diode D2, a diode D3, a diode D4, a diode D5 and a transformer form a resonant circuit, the voltage output by the PFC main circuit 2 is subjected to DC-DC conversion, coupling coefficients of two secondary windings of the transformer are different from those of the primary windings, M6 and the secondary winding are closely coupled with the primary winding, the primary winding 1, when the constant current output voltage output of the primary side resonant DC-DC circuit is controlled by a constant-voltage output voltage regulator, the primary side constant-frequency constant-voltage output voltage regulator circuit through a first resonant constant-voltage output constant-voltage output voltage regulator circuit, the first resonant constant-frequency constant-frequency constant-frequency constant-frequency constant-.

The above-described embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention in any way, and other variations and modifications may be made without departing from the scope of the claims.

Claims

1. An L ED driver, comprising:

the input end of the PFC main circuit is used as the input end of the L ED driver and is used for being connected with a power supply, the output end of the PFC main circuit is connected with the input end of the resonant DC-DC circuit, the output end of the resonant DC-DC circuit comprises a constant voltage output end and a constant current output end, the input end of the current regulating circuit is connected with the constant current output end, the output end of the current regulating circuit is connected with the frequency control driving circuit, the current regulating circuit is used for detecting the current output by the constant current output end and outputting a first feedback signal to the frequency control driving circuit, the frequency control driving circuit outputs a first driving signal to the resonant DC-DC circuit according to the magnitude of the first feedback signal, the current output by the constant current output end is maintained to be constant through the working frequency of the resonant DC-DC circuit, the input end of the voltage regulating circuit is connected with the output end, the output end of the voltage regulating circuit is connected with the isolation circuit, the output end of the voltage regulating circuit is used for detecting the constant voltage output by the constant voltage output end of the constant voltage regulating circuit, the constant voltage output by the constant voltage regulating circuit, and the constant voltage output circuit, and the constant voltage regulating circuit outputs a second constant voltage control signal to the constant voltage output by the constant voltage control driving circuit according to the constant voltage output of the constant voltage control.

2. An L ED driver as claimed in claim 1, wherein the PFC main circuit includes an inductor L, a switch tube S0, a diode D1 and a capacitor C0, one end of the inductor L is connected to a positive power supply terminal, the other end of the inductor L is connected to one end of the switch tube S0 and to an anode of the diode D1, the other end of the switch tube S0 is connected to one end of the capacitor C0 and to a negative power supply terminal, the other end of the capacitor C0 is connected to a cathode of the diode D1, and both ends of the capacitor C0 are also connected to the resonant DC-DC circuit as an output terminal of the PFC main circuit.

3. The L ED driver of claim 1, wherein the resonant DC-DC circuit further comprises a switching unit, a resonant capacitor Cr, and a transformer, the transformer comprises a primary winding N1, a secondary winding M1, and a secondary winding M2, the primary winding N1 and the resonant capacitor Cr are connected in series and then connected to the switching unit, the other two ends of the switching unit are used as input terminals of the resonant DC-DC circuit, the secondary winding M1 is used as a constant voltage output terminal through a first rectified output terminal after rectification, and the secondary winding M2 is used as a constant current output terminal through a second rectified output terminal after rectification.

4. The L ED driver of claim 3, wherein the coupling coefficient of the secondary winding M1 to the primary winding N1 is greater than the coupling coefficient of the secondary winding M2 to the primary winding N1.

5. An ED driver as claimed in claim 3, wherein the switching unit in the resonant DC-DC circuit comprises a switching tube S and a switching tube S, the resonant DC-DC circuit further comprises a diode D, a capacitor C and a resistor Rs, a first end of the switching tube S is used as an input positive end of the resonant DC-DC circuit, a second end of the switching tube S is respectively connected with a first end of the switching tube S and one end of a primary winding N, a second end of the switching tube S is used as an input negative end of the resonant DC-DC circuit and connected with one end of the resonant capacitor Cr, the other end of the resonant capacitor Cr is connected with the other end of the primary winding N, the secondary winding M and a secondary winding M have tap ends, a first end of the secondary winding M is connected with an anode of the diode D, a second end of the secondary winding M is connected with a cathode of the diode D via the diode D, a cathode of the diode D is connected with a tap end of the secondary winding M, a second end of the secondary winding M is used as an anode of the tap end of the diode D, a cathode of the secondary winding is connected with an output end of the diode D, a cathode of the secondary winding C of the secondary winding is connected with an output end of the diode D, a cathode of the secondary winding C, a cathode of the diode D is connected with an output end of the diode D, and a constant-voltage regulating diode D, a cathode of the diode D, and a diode D are connected with a cathode of the diode D, and a diode.

6. An L ED driver as claimed in claim 5, wherein the voltage regulation circuit includes an operational amplifier U1, a resistor R1, a resistor R2, a resistor R3 and a capacitor C4, the negative input terminal of the operational amplifier U1 is connected to the first terminal of the capacitor C4, the one terminal of the resistor R1 and the one terminal of the resistor R2, the other terminal of the resistor R1 is connected to the first terminal of the capacitor C1, the other terminal of the resistor R2 is connected to the second terminal of the capacitor C1, the second terminal of the capacitor C4 is connected to the output terminal of the operational amplifier U1 via the resistor R3, and the positive input terminal of the operational amplifier U1 is inputted with the voltage reference signal Vref.

7. The L ED driver of claim 1, wherein the isolation circuit includes an opto-coupler, an input of the opto-coupler is connected to the voltage regulation circuit, and an output of the opto-coupler is connected to the drive control circuit.

8. The L ED driver of claim 5, wherein the current regulation circuit includes an operational amplifier U2, a capacitor C5 and a resistor R4, the negative input terminal of the operational amplifier U2 is connected to the first terminal of the capacitor C5 and the second terminal of the resistor Rs respectively, the second terminal of the capacitor C5 is connected to the output terminal of the operational amplifier U2 through the resistor R4, and the positive input terminal of the operational amplifier inputs the current reference signal Iref.

9. The L ED driver of claim 5, wherein the frequency control driving circuit includes a resonant control chip, a voltage controlled oscillator and a driving circuit, the voltage controlled oscillator receives the first feedback signal from the current regulating circuit and determines the magnitude of the frequency of the switch tube S1 and the switch tube S2 according to the magnitude of the first feedback signal, the resonant control chip transmits the frequency signal to the resonant control chip, and the resonant control chip generates the driving signal according to the frequency signal by the driving circuit and outputs the driving signal to the switch tube S1 and the switch tube S2.

10. The L ED driver of claim 2, wherein the driving control circuit includes a PFC control chip, a third operational amplifier, a fourth operational amplifier and an RS flip-flop, the positive input terminal of the third operational amplifier and the negative input terminal of the fourth operational amplifier input the second feedback signal transmitted by the voltage regulating circuit, the negative input terminal of the third operational amplifier input a second voltage reference signal, the output terminal of the third operational amplifier is connected to the S terminal of the RS flip-flop, the positive input terminal of the fourth operational amplifier input a third voltage reference signal, the output terminal of the fourth operational amplifier is connected to the R terminal of the RS flip-flop, the Q terminal and the Qnon terminal of the RS flip-flop are both connected to the PFC control chip, and the PFC control chip is connected to the switching tube S0.