TW201234914A - LED driving circuit and feedback control circuit thereof - Google Patents

Abstract

The present invention discloses a LED driving circuit to drive a LED module. The LED module has at least a string of LEDs which are parallel with each other. The LED driving circuit includes a converting circuit and a feedback control circuit. The converting circuit is coupled to the LED module and receives a control signal at least, such that the power of an input voltage is converted to an output voltage to driving the LED module. The feedback control circuit generates the control signal at least to control the converting circuit processing the voltage transfer according to a feedback signal. Beside from that, the feedback control circuit receives a dimming signal and operates in a first state or a second state according to the dimming signal. Wherein, the feedback control circuit adjusts the duty cycle of the control signal, such that the duty cycle of the control signal is more than or equal to a predetermined duty cycle, as the dimming signal in the second state converts a predetermined periods in the first state at first.

Description

201234914 r VI. Description of the Invention: [Technical Field] The present invention relates to a light-emitting diode driving circuit and a feedback control circuit thereof, and more particularly to a light-emitting diode capable of improving the light-adjusting accuracy of a light-emitting diode Drive - circuit and its feedback control circuit. [Prior technology] If the light-emitting diode has long service life, high luminous efficiency, and stable brightness and fastness, it is regarded as the main source of illumination and illumination for the next generation. Lu Xunguang's diodes can be used in a wide range of lighting applications, including indoor lighting, outdoor lighting, advertising signs, etc. As the light-emitting diodes replace the current illumination light one by one, how to obtain a stable light source and a color light-emitting diode and provide appropriate protection, so that the light-emitting diode can exert its characteristics has become an important topic today. Please refer to the first figure for a circuit diagram of a conventional LED driving circuit. The LED driving circuit comprises a feedback control circuit, a conversion circuit 110 and a light emitting diode module 12A. The conversion circuit 11 is coupled to an input power source VIN' to convert the power of the input power source vin according to a control signal sci (for example, step-up or step-down) to output an output voltage VOUT to the light-emitting diode 120 to drive the light-emitting diode The polar body module 120 emits light. In this implementation, the conversion, circuit no is a DC-DC converter circuit, including an inductor li.

The transistor switch SW1, a rectifying diode K1 and an output capacitor (^. One end of the inductor L1 is connected to the input power source VIN and flows through an inductor current ili, and the other end is connected to one end of the transistor switch swi, and the transistor switch The other end of the SW1 is grounded through a resistor R1. One end of the output capacitor C1 is connected to the connection point of the inductor L1 and the transistor switch SW1 through the rectifying diode D1, and the other end is grounded. The LED module 120 has a plurality of LEDs. The polar body string and the light-emitting diode strings are connected in parallel with each other. In addition, in order to ensure that any one of the light-emitting diodes 12 of the light-emitting diode module 12 has substantially the same current, the light-emitting diode driving circuit can increase the force. I 201234914 Guangguang Pingping 2:: The corpse 'has a plurality of current balancing terminals m~Dn corresponding to a plurality of LED strings in the 120, to balance the complex number, the current of the first polar string 'to make each string The current of the LED string is stabilized in one [2:; because the string of LEDs flows through the predetermined current value; the required driving voltage must be maintained at a minimum operable voltage value. Second can be increased - voltage _ circuit 14G The plurality of current flat soils = and according to the mother-light-emitting diode flow through the predetermined current value of the electricity = the required cross-over voltage is not _, resulting in a plurality of current balance terminals D1 ~ Dn of the electric low, the same. In order to make the current balance terminals D1 D Dn of the current balancing unit U0 can be hoisted, the current of the ship can be a predetermined value, and the voltage side circuit 140 generates a feedback signal according to the lowest potential between the current balance terminals D1 D Dn. The electric clear L balance unit 130 simultaneously receives a dimming signal DIM, and controls the current flowing through the LED module 12 according to the state of the dimming nickname. In this circuit, the s ambient light signal DIM Switching between a first state and a second state, when the optical signal DIM is in the first state, the LED module 12 电流 flows a current of a predetermined current value; and the dimming signal DIM is in the second state. The light-emitting diode module 120 stops flowing current. The voltage detecting circuit 14A can include a plurality of diodes, and the negative ends thereof are respectively coupled to the plurality of current balancing terminals D1 D Dn′ and the positive ends thereof are mutually Connected and coupled to a driving power supply vcc through a resistor. The circuit 100 includes a feedback unit 150 and a pulse width control unit 160. The feedback unit 15 includes an amplifying unit 152 and a compensation unit 154. The amplifying unit 152 receives the feedback signal Fbl and a reference signal vrl. After the output signal is generated and compensated by the compensation unit 154, the pulse width control unit 160 includes a pulse width modulation unit 162 and a driving unit 164. The pulse width modulation unit 162 receives the output signal. The pulse width control signal Veal and a triangular wave signal are used to generate a pulse width modulation signal S1. Then the driving unit 164 receives the pulse width control signal si to generate a control signal Scl according to the dimming signal DIM. The feedback control circuit 1 controls the conversion circuit 110 to convert the power when the dimming signal DIM is in the first state, and controls the conversion circuit 110 to stop the conversion of the power when the dimming signal DIM is in the second state. ' *.Λ · i , 201234914 Well Lei iitH' secret 154 touch can not instantaneously pull _ ^ P electric valley transient response), therefore, when the dimming signal inductance L1 < - the highest value of the instrument 10 can not The power of the second coffee is insufficient. The output voltage ν〇υτ will first drop to the tii!1-stabilized voltage, and this will cause the current flowing through the LED module to dim the DIM in the second state. The first - _ - segment = constant current value is still low, which affects the dimming accuracy of the LED module

SUMMARY OF THE INVENTION In view of the prior art, the 'light-emitting diode driving circuit has a problem of inaccuracy in the dimming process. The present invention is in the dimming domain, and the off-state is just switched to the J-table open state - During the period of time, the output power of the conversion circuit is rapidly increased: the current of the LED module can be quickly recovered to a predetermined current value. In order to achieve the above object of the present invention, the present invention provides a feedback control circuit for controlling a conversion circuit to convert the power of a power source to drive a light emitting diode module. The light emitting diode module has at least one light emitting diode string and the light emitting diode strings are connected in parallel with each other. The feedback control circuit includes a feedback unit and a pulse width control, 7〇. The feedback unit receives a feedback signal representing a state of the LED module to generate a pulse width control signal, wherein the feedback unit includes a dimming adjustment unit 2 for timing according to a dimming signal Generate a dimming adjustment signal. The pulse width control element is based on the pulse width control signal to generate at least one control signal to control the circuit for power conversion. The dimming signal is switched between a first state and a second state, and the dimming adjustment signal of the feedback unit adjusts the pulse width control after the dimming signal is turned from the second state to the first state. The signal increases a duty cycle of at least one of the control signals by a predetermined value. The invention also provides a feedback control circuit for controlling a conversion circuit to convert the power of a power source to drive a light-emitting diode module, and the feedback control circuit is widely distributed. The unit is connected to the state of the thief table light-receiving signal to generate a pulse width control signal. Correctively, the system 70 generates at least a control signal according to the pulse width control to control the circuit to perform power conversion. Wherein, the dimming signal is in the "first state" and the state of the m-switching "pulse width control unit in the dimming signal from the second state, the first state - the time period 'will at least - the control signal is added to a predetermined value . The invention further provides a light-emitting diode driving circuit for driving an emitter body and the 'light-emitting diode group having at least one light-emitting diode string and the light-emitting diode strings being connected in parallel with each other. The LED driving circuit includes a conversion circuit and a feedback control circuit. The conversion circuit is coupled to the LED module _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ The feedback control circuit generates at least one control transistor to control the conversion circuit for voltage conversion according to a feedback signal, and the feedback control circuit receives a second adjustment: and operates according to the dimming signal in a first state or a second state. The one feedback control circuit is in the second state of the dimming _ to the first state 乂 - the time period 卿 at least - the king of the control position, so that at least ^

The job title of the signal is greater than or equal to the position of the scheduled guard. The above summary and the following detailed description are exemplary in order to illustrate the scope of the claims. Other objects and advantages of the present invention will be set forth in the description and drawings. [Embodiment] Referring to the second figure, a circuit of a light-emitting diode driving circuit according to a first preferred embodiment of the present invention is shown. The light-emitting diode circuit includes a 2GG and a conversion circuit 210 for driving - the light-emitting diode, the light-emitting diode module 220 has a plurality of light-emitting diode strings and the light-emitting diode string Parallel to each other. The conversion circuit 210 is coupled to an input power source

201234914 Wide "VIN" is used to convert the input power to a power conversion according to a control signal Sc2 (for example, step-up or step-down and output-output voltage VOUT to drive the LED module 22 to emit light. In this embodiment, The conversion circuit 21 is a DC-DC converter circuit including an inductor L2, a transistor switch SW2, a rectified diode 2, and an output capacitor C2. The end of the inductor L2 is lightly connected to the input power source VIN and flows through - Inductor current IL2, the other end of the woven transistor switch sprinkle 2 • One end 'and the other end of the transistor switch SW2 is grounded. The end of the output capacitor C2 through the rectification of the second shop K2 secret L2 and the connection point of the electro-ceramic switch SW2 'The other end is grounded. In order to ensure that any one of the two diodes of the light-emitting diode set 22 is flowing through the substantial phase, the light-emitting diode driving circuit can be increased - the current balancing unit 230 has a plurality of currents The balanced terminals m to Dn are coupled to the plurality of LED strings in the LED module 220, and the currents of the LEDs and the LEDs are stabilized in the current of the LED strings. Predetermined current value. The light diodes flow through the predetermined current value, and the voltages of the plurality of current balancing terminals m~Dn are different. To make the current balance unit 23〇 current balance terminal 〜1~加均The current can be controlled by the operation of the current operation, and the current value of the current balance D1 to Dn must be maintained at a minimum operable voltage value. For this reason, the present embodiment can increase the voltage detection circuit 24〇. , a plurality of current balancing terminals 仞~Dn are connected, and a=Fb2 is generated according to the lowest potential between the current balancing terminals D1 DDn. The current balancing unit 23 接收 simultaneously receives the dimming signal, and according to the dimming signal DIM The state controls the LED mode & 22 〇 flow or not. In this circuit, the dimming signal DIM is switched between a first state and a second state, and the dimming signal DIM is in the first state. The second module 220 flows through the current of the predetermined current value; the dimming signal Dm is at the 22nd age of 22g to stop the money inspection. The cake_electricity ί can include a plurality of comparators and logic components 242, wherein The opposite ends of the comparator are respectively coupled to the plurality of current balancing terminals D1 to Dn, The feedback terminals 200 are connected to each other and receive a reference power supply Vref. The logic unit 242 outputs the feedback signals of the plurality of comparators to the feedback control system 201234914 "f 200. The feedback control circuit 200 includes a feedback unit 250 and a The pulse width control unit 260' generates a control signal Sc2 according to the feedback signal Fb2 to control the conversion circuit 210 to convert the power of the input power source VIN to drive the LED module 22A. The feedback unit 250 receives the representative LED. The feedback signal Fb2 of the state of the module 220 is used to generate a pulse width control signal Vea2, wherein the feedback unit 2sn white charging unit 252, the discharging unit 254, and the compensation capacitor unit 270' charging unit 252 have a first current. The source η is connected in series with a first switch SW01 and coupled to the compensation capacitor C. The discharge unit 254 has a second current source 12 connected in series to a second switch SW02. When the voltage of either end of the plurality of current balancing terminals D1 DDn is less than the reference power source Vref, the feedback signal Fb2 is at a low level, and the clock causes the first current source II to charge the compensation capacitor C through the second switch SW01, when a plurality of When all the terminal voltages of the current balancing terminals D1 DDn are higher than the reference power source Vref, the feedback signal Fb2 is at a high level, so that the second current source 12 discharges the compensation capacitor c through the second switch SW02. The pulse width control unit 260 includes a pulse width modulation unit 262, a dimming control unit 266, and a driving unit 264 for adjusting the duty cycle of the control signal Sc2 according to the generated pulse width control signal Vea2. The pulse width modulation unit 262 can be a comparator, and the non-inverting input terminal receives the pulse width control signal, receives a ramp signal from the 2 and the inverting input terminal, and generates a pulse width modulation signal S2 to drive accordingly. Unit 264. The dimming control unit 266 receives the dimming signal DIM, φ such that the dimming signal DIM is in the second state of the representative, OFF", generating a pulsed period, one dimming control signal P2; the dimming signal DIM is represented, 〇N,, in the first state, one of the high level dimming control signals p2 is generated. The driving unit 264 simultaneously receives the pulse width modulation signal S2 and the dimming control signal p2. When the dimming signal DIIV^ is the first In the state, the driving unit 264 generates a signal according to the pulse width modulation signal, and generates a signal Sc2, so that the LED module 22 is stably illuminated; when the dimming signal DIM is in the second state, the driving unit 264 is based on the dimming. The control unit 266 5, ?:], the control signal Sc2 of the duty cycle, the current balancing unit 230 also stops the current flowing through the LED module 22 according to the dimming signal DIM, so that the light is emitted

201234914 "r check 22 〇 stop illuminating. In this way, the 峨 control circuit (4) converts electricity to maintain the conversion circuit 210 for minimum power conversion to supplement the power loss caused by the circuit, so that the conversion circuit 21 is pressed VOUT _峨_骑—秘(四)电杂 = ' dimming = section single 270 is coupled to the first switch s_ and the compensation capacitor c ^ according to the dimming signal DIM when the paste pulse width control view number Vea2 quasi-circumference signal The brain has just turned to the first state since the second state - when 1 ^ 1 week, the light is adjusted by the early element 270, the pulse width control fiber (four) is raised by a predetermined potential week _ Ϊ 控, the duty cycle of the number is increased - the predetermined value is rapidly increased Conversion. The output power of the circuit makes the LED module = good light-emitting diode module 22^^ turn light--the state can't rise quickly and the dimming is not fine; the ϊ ϊ four pictures 'for the third ride Referring to the third figure, one of the dimming adjustment units is shown, and the dimming adjustment unit 27 is 〇 ΐ 箪 ^ 疋 疋 272 and a level modulation unit 280. The lower end generates a first level signal and ^ The upper end generates a second level signal C0mp2, and the level 罝 / f, and the compensation capacitor C. The level modulation The element 280 includes a =8=variation unit 28. The root=selection message Sel2, wherein the selection unit 272 selects to output the first-level signal C〇mi or the first j Sel2 to be 1==. The intermediate clock CLK1 receives the feedback signal Fb2, and the reverse output terminal Q1', the reverse output terminal Q1, and the 鸲D1 are coupled to one of the clock control terminals (the XD D type flip-flop 284). The second 1> type positive and negative $ 284 ί type positive and negative device 284. The input of D4 is connected to an inverted output terminal. · , .... 201234914 ^ r Q2, one of its output terminals Q2 The clock control terminal CLK3 is connected to one of the third D-type flip-flops 28S. One input terminal D (four) of the third D-type flip-flop 285 is connected to a high-level signal 1". The dimming signal DIM is inverted by the reverse gate 282, respectively. Output dimming button DIM to one of the three D-type flip-flops 283, 284 and 285 resetting the end to green R2 and R3 to reset the three d-type positives in the second state of the low level The output signal of the device (that is, the output signal is low level). Then, the gate 286 receives the output signal of the third D-type flip-flop 285 and the reverse dimming signal. Pulse width control No. Vea2, as shown in the figure 5, when the dimming signal DIM is in the second state, the first D type is offering: the goods.-to-, the counter 284 and the third D-type flip-flop 285 are the main ones. In order to be in the right position, the selection unit 272 selects the first criterion theory at this time.

ί control signal; and when the optical signal * _ in the P th ^ (four) two - state - time period, - the starting output voltage νουτ' Ί ·, 犹 ΪΓ ΪΓ ΪΓ 、 、 、 、 、 、 犹 犹 , , , , , , , , , , , , , , , , , , , , , , , , = 285 output signal loss? 7? Na Μ ^ choice. The S 2 output is called the low level. At this time, the selection unit Com^i first-^ signal C〇mp2 is used as the pulse width control signal Vea2. Because of the xR's lightning position', therefore, the pulse width control signal Vea2 is superimposed with 11 electric system, such as the working week __ plus, the inductor is working ϊί to raise the potential of the output voltage V0UT and return to the mode to trigger to the high level. third. Level signal —======= Section unit 270 is based on 201234914

Period of time. Compared with the second figure, the inductor current IL of the embodiment can be rapidly increased, so that the falling amplitude and time of the output voltage VOUT of the embodiment are smaller than the output voltage VOUT of the second figure, so as to avoid the LED module. Dimming is not accurate. Next, please refer to FIG. 6 for a circuit diagram of a two-light-emitting diode driving circuit according to a second preferred embodiment of the present invention. Light-emitting diode driving circuit

A feedback control circuit 30.0 and a conversion circuit 310 are used to drive a transmitter and a body module 32A. The conversion circuit 31 is coupled to the 'parent input power supply VAC' through a bridge rectifier and converts the AC input power according to a control signal Sc3: the source VAC> performs a power conversion and drives the LED module 32 to emit light. In the present embodiment, the conversion circuit 31 is a forward conversion circuit including a transformer T3, a transistor switch SW3, rectifying diodes K3a, K3b, an inductor ^, and an output capacitor C3. One end of the primary side of the transformer T3 is coupled to AC = input power VAC, and the other end is coupled to one end of the transistor switch SW3, and the electric crystal. - The other end of SW3 is grounded through a resistor R3 to generate a current feedback signal IFb3. The output capacitor C3 is coupled to the secondary side of the transformer T3 through the rectifying diode leg and the driver L3. A voltage detecting circuit 312 is coupled to the valley C3 to generate a voltage feedback signal VFb3 representing an output voltage ν 〇υ τ. In order to ensure stable illumination of the LED module 32, the LEDs are coupled to a current source Is such that an output current Ι〇υτ is stabilized at a pre-turn, and the current source II is simultaneously received by the current source Is. The dimming signal DIM is controlled, and the current flowing through the LED module 320 is controlled according to the condition of the dimming signal. In the illuminating body driving circuit, the dimming signal DIM is switched between a first state and a second state, and when the dimming signal DIM is in the first state, the illuminating diode module 320 flows through the predetermined current value. When the dimming signal DIM is in the second state, the LED module 32 stops flowing current. The control circuit 300 includes a feedback unit 35A and a pulse width control unit 360' for controlling the conversion circuit 3 to convert the power of the AC input power source VAC to drive the optical diode module 32A. The feedback unit 35A includes a comparator 352, a signal superimposing unit 354 and a dimming adjusting unit 37, and the signal superimposing unit 354 is distributed 201234914 to receive the current feedback signal IFb3 and the voltage feedback signal vFb3 to generate a feedback signal Fb3. . The dimming adjustment unit 370 includes a selection unit 372 and a level modulation unit 380. In this embodiment, the level modulation unit 38A includes a delay unit το 382, a trigger unit 384, and an SR flip-flop 386. The trigger t 384 is a click circuit with a positive edge trigger, and receives the dimming signal DIM, so that the dimming signal DIM is just turned to the first state in the second state, the touch unit 384 outputs a high level to the set terminal S of the SR flip-flop 386; and the delay unit 382 receives the dimming signal DIM and outputs a message to the reset terminal R of the flip-flop 386 for a predetermined delay time to cause the flip-flop 386 Reset. According to this SR, the output terminal Q of 386 generates a selection signal %13 to the selection unit 372. When the selection signal se13 is at a low level, the selection unit 372 selects two, a level signal C〇mp3; when the selection signal Sel3 is at a high level, the element 372 selects a second level signal c. 〇mp4, in order to generate a dimming tone number Vr3 'where the second level 峨c〇mp4 is higher than the first standard, i〇mp3. Then, the inverting input terminal of the comparator 352 receives the dimming adjustment signal Vr3, and the non-inverting input terminal receives the feedback signal Fb3, according to which, a pulse width control signal Vea3, where the pulse width control signal Vea; A pulse signal. The pulse width control unit 360 includes a pulse width modulation unit 362 and a drive f element f64. The pulse width modulation unit 362 can be an SR flip-flop. The set terminal s of the pulse width changing unit 362 receives a clock signal pu, and a reset terminal R receives the pulse width control signal Vea3. When the SR flip-flop 362 receives the clock signal I > U at the set terminal s, a pulse width modulation signal % is generated by the output terminal Q, and the circuit 364 is driven. The dimming control unit 366 generates a dimming control unit P3 having a dimming signal according to the dimming signal. The circuit operation mode is substantially the same as that of the dimming control unit 266 shown in the third figure, and details are not described herein. Then, the drive, power, 364 simultaneously receives the pulse width modulation signal % and the dimming control signal p3. When the FIM DIM is in the first state, at this time, the driving unit 364 adjusts the pulse according to the pulse width, p generates the control signal Sc3; when the dimming signal DIM is in the second state, the =I element 364 is based on the dimming control signal 35p3 Generate control signal (10): The value of the signal is 'when the dimming is reduced from the second state to the first state, a predetermined 14 II, ΐΊ; 201234914 = bit C unit 37 ° * transmits the first level unit c- P3 is changed to the first | single omp4 to rise a predetermined potential to the comparator M2 - group vea3 s 〇 3 This 'inductance current flowing through the inductor 丄 3 can rapidly increase the voltage of the νουτ τ drop, and thus improve Light-emitting diode; dimming minus dim $ dimming caused by the second state just turned into the first state. Referring to the seventh figure, there is shown a circuit diagram of a first-pole driving circuit according to a third preferred embodiment of the present invention. The LED housing circuit includes a binary circuit 400 and a conversion circuit for driving a light-emitting diode and 4 < The feedback control circuit: 4〇〇 receives a feedback signal FM, and accordingly controls to generate a control signal Sc4, thereby controlling the conversion circuit to reduce. The input end of the switching circuit 410 is lightly connected to an input power source, and the output terminal is coupled to the light emitting body module 420 and outputs an output voltage ν 〇υ τ. The light-emitting diode = 420 has a plurality of light-emitting diode strings and these light-emitting diode strings are connected in parallel with each other. In addition, in order to ensure that any of the LEDs of the LED module 42 is flowing through a substantially phase-stabilized current, the LED driving circuit can add a current balancing unit 430 having a plurality of current balancing terminals. D1~Dn are correspondingly coupled to the plurality of LED strings of the LED module 420 to balance the currents of the LED strings, and the current flowing through each string of LEDs simultaneously flows. A current detecting resistor R4 is generated and a feedback signal FM is generated. The feedback control circuit 400 includes a feedback unit 45A and a pulse width control unit 46A. The feedback unit 450 includes an amplification unit 452, a compensation unit 454, and a dimming adjustment unit 47A. The dimming adjustment unit 470 includes a selection unit 472 and a level=variation unit 480. In this embodiment, the level modulation unit 480 includes a delay unit 482, a trigger unit 484, and an SR flip-flop 486. Wherein, the touch, the element 484 is a click circuit with a positive edge trigger (,ne Sh〇t), and receives the smart light signal DIM, so that the dimming signal DIM is triggered when the second state is just turned into the first state. The unit 484 outputs a high level to the set terminal S of the SR flip-flop 486; and the delay unit 482 receives the dimming signal DIM and transmits 15 Γ 201234914 after a predetermined delay time to the reset terminal R of the flip-flop 486. The flip flop 486 is reset. Accordingly, the output terminal q of the SR flip-flop 486 transmits a selection signal sd4 to the selection unit 472. The selecting unit 472 selects a first level signal Comp5 when the selection signal Sd4 is at a low level, and selects a second level signal Comp6' to output a dimming signal according to the selection signal sel4 at a high level. Vr4, wherein the level of the second level signal Comp6 is higher than the level of the first level signal c〇mp5. Compared with the sixth figure, the non-inverting input terminal of the amplifying unit 452 receives the dimming adjustment signal Vrt\f, and the phase input terminal receives the feedback signal 1^4' to generate an error signal accordingly. The 1 occupant unit 454 generates a pulse width control signal 乂 Qiu 4 according to the error signal. The compensation single = magic 4 generally includes the capacitance and the resistance, and adjusts the voltage gain versus frequency relationship of the compensation unit 454 according to the circuit of the actual application, so that the feedback control of the feedback control circuit 400 has a better transient response. The pulse width control unit 46A includes a pulse width modulation unit 462, a dimming control unit 466, and a driving circuit 464 for adjusting the duty cycle of the control signal Sc4 according to the pulse width control signal Vea4. The pulse width modulation unit 462 can be a comparator, and the non-inverting input terminal receives the pulse width control signal Vea4 and the inverting input terminal receives a ramp wave number to generate a pulse width modulation signal S4 to the driving unit 464. . The dimming control unit 466 generates a dimming control signal P4' having a pulse signal according to the dimming signal. The circuit operation mode is substantially the same as that of the third dimming control unit 266, and details are not described herein. Then, the driving circuit 464 receives the pulse width modulation signal S4 and the dimming control signal P4. When the dimming signal DIM is in the first state, at this time, the driving unit 464 generates the & * signal SC4 according to the pulse width modulation signal S4; when the dimming signal DIM is in the second state, the driving unit 464 ^ according to the dimming control Signal P4 generates control signal Sc4. It should be noted that each dimming signal DIM is changed from the second state to the first state as a pre-g; the light adjusting unit 470 is changed from the transmitting first-level unit C() mp5 to the second level ^ 兀C〇 mP6 increases the potential of the signal to the non-inverting end of the comparator 452 to control the potential of the signal Vea4, so that the operating period of the control signal Sc4 is increased, so that the inductor current IL is rapidly increased and the output voltage V0U is reduced; The time and amplitude of the drop further improve the dimming inaccuracy caused by the dimming diode module 42 when the DIM is turned to the first state in the second state. Next, please refer to the eighth figure, which is a circuit diagram of a pulse control unit according to a fourth preferred embodiment of the present invention. The pulse width control unit 56A includes a pulse width modulation unit 56=, a driving unit 564, and a dimming control unit 566. The pulse width control unit 56 can also include a dimming adjustment unit 57 to adjust the duty cycle of a control signal Sc5 in accordance with the pulse width control unit 26A shown in the third figure. The dimming adjustment signal 570 receives the pulse width control signal vea5 and the dimming signal DIMj and adjusts the pulse width control signal according to the timing of the dimming signal DIM to generate a s ambient light adjustment signal γΓ5. In this example, the dimming signal

[Switching between a first state and a second state] wherein the dimming adjustment signal; Vr5 is raised by a predetermined potential and transmitted after the dimming signal DIM is turned from the second state to the first state As for the wide adjustment unit 562, in the state (such as continuing the first state or continuing the second state), the dimming adjustment signal only uses the pulse width control signal vea5 as the dimming adjustment signal Vr5 output. Without making any adjustments. The opposite end of the pulse width modulation unit 562 receives a ramp signal, and the non-inverting terminal receives the dimming adjustment signal Vr5 to generate a pulse width modulation signal S S5 to the moving unit 564. The dimming control unit applies a dimming control signal p5 according to the dimming signal, and the circuit operation mode is as shown in the first blue figure. The dimming control unit 266 is substantially the same, and the seventh connection is not described here. When the drive unit 564 receives the pulse width modulation signal S5 and the dimming control signal/household 5 illuminating signal DIM as the first state, the driving unit 564 generates the control signal Sc5 according to the pulse width=variation signal j; When the dimming signal DIM is the second state drive unit 564, the control signal Sc5 is generated according to the dimming control signal P5. Note that when the dimming signal DIM is changed from the second state to the first state, the time interval, the pulse width modulation signal S5 is lengthened by a predetermined pulse width, so that the duty cycle of the control tiger Sc5 is increased by one predetermined. The value is used to quickly increase the power of the conversion circuit, thereby improving the dimming of the LED module when the dimming signal DIM is in the second state, and the dimming caused by the first state is inaccurate. One of the interfaces, please refer to the ninth figure, which is a circuit diagram of a pulse width control unit according to a fifth preferred embodiment of the present invention. The pulse width control unit 66 includes a pulse 17 201234914 $ modulation unit 662, a driving unit 664, and a dimming control unit 666. The pulse width control unit 66 can also include a dimming adjustment unit 67 to adjust the duty cycle of a control signal Sc6 in accordance with the pulse width control unit 26A shown in the third figure. The dimming signal 670 is coupled to a ramp signal to generate a dimming signal Vr6 according to the timing of the dimming signal piM. In this embodiment, the dimming signal DIM is between a first state and a second state. Switch. Please refer to the tenth figure, wherein the dimming adjustment unit 670 is turned from the second state to the dimming signal DIM, and the amplitude (wave peak) of the triangular wave signal is reduced by a period of time from a state. The light adjustment signal Vr6 is transmitted to the pulse width modulation, and in other states (such as continuing the first state or continuing the second state), the dimming adjustment signal Vr6 only performs the action of transmitting the ramp signal. The pulse width modulation unit=^ the opposite end receives the dimming adjustment signal and the non-inverting terminal-pulse width control signal Vba6, thereby generating a pulse width modulation signal % to the drive 664i and the dimming control The single-it 666 dimming signal generates a dimming control signal P6 having a pulse signal, and the dimming control unit 266 of the electric material mode is substantially the same, and will not be described herein. Next, the driving unit 664 is connected at the same time = pulse width machine minus S6. And dimming control signal P6. When the dimming signal DIM is in the first state, the driving unit 664 generates the control signal Sc6 according to the pulse width modulation signal S6; when the dimming signal DIM is in the second state, the driving unit generates the control ship according to the dimming control 峨P6 No. Se6. It should be noted that when the dimming signal DIM is changed from the second state to the first state for a period of time, the pulse width and the variable signal S6 are lengthened by a predetermined pulse width, so that the working period of the control signal Sc6 is increased by i. 'Resolution _ change the ridge force, and then improve the quilt _ optical signal DIM is the second state just turned into the first state caused by the dimming inaccuracy. Referring again to the tenth-figure, there is shown a schematic diagram of a control S element according to a sixth preferred embodiment of the present invention. The pulse width control unit includes an λ drive circuit 764 and a dimming control unit 7. If the pulse width control unit 260, the pulse width control unit leakage can also have 3 - dimming 5 Lin Dan Fan 77 〇 to adjust a control signal W according to this. 乂, fine mine, 丨一 201234914 cycle . The opposite end of the pulse width modulation unit 762 receives a ramp signal and the non-inverting terminal receives a pulse width control signal Vea7 to generate a pulse width modulation signal S7 to the dimming adjustment unit 770. The dimming adjustment unit 770 includes a delay trigger unit 772 and an SR flip-flop 776. The delay trigger unit 772 is coupled to the pulse width modulation unit 762 to generate a pulse for a predetermined period of time after the dimming signal DIM has just turned from the second state to the first state. The signal is applied to the reset terminal R. of the SR flip-flop 776, so that the pulse width adjustment width of the dimming adjustment signal Vr7 generated by the dimming adjustment unit 77 is longer than the pulse width modulation signal S7 by a predetermined time period. The dimming control unit 766 generates a dimming control signal having a pulse signal according to the dimming signal DIM? 7. The circuit operation is substantially the same as the dimming control unit 266 shown in Fig. f. 'It will not be described here. Then, the driving circuit 764 receives the dimming adjustment signal Vr7 and the dimming control signal P7 at the same time. In this embodiment, the dimming signal DIM is switched between a first state and a first and second states. When the dimming signal DIM is in the first state, the mobile unit JJ764 generates the control signal sc7 according to the pulse width modulation signal S7; and when the dimming household tiger DIM is in the second state, the driving unit 764 is based on the dimming control signal P7. Production ~ Health Control sfl No. Sc7. It should be noted that when the dimming signal DIM is changed from the first state to the first state, the dimming adjustment signal w is lengthened by a predetermined pulse width, so that the duty cycle of the control signal Sc7 is increased by a predetermined value. Quickly increase the output power of the conversion circuit and reduce the amplitude between the output drops. The dimming signal (10) is the dimming inaccuracy caused by the first state when the first state is turned. Ming is fully in line with the three requirements of the patent: novelty, progressiveness, and utilization. The present invention has been disclosed in the above preferred embodiments, and it should be understood that the embodiment is only used to describe the present invention, and should not be construed as a detail of the present invention. It should be noted that the warranty of the month of the month is subject to the definition of the patent application scope of the τ text. [Simple diagram of the diagram] Circuit diagram of the LED diode driving circuit of 201234914. The riding light-receiving diode (4) is a circuit-switching process. The figure is a circuit diagram of a pulsating circuit according to a first preferred embodiment of the present invention. H... J four = according to the third figure - dimming adjustment unit - the embodiment of the 'light-emitting diode drive: road schematic electric four-riding material two minus Lin electric oblique dimming process ten Jingji body drive Three Preferred Embodiments Fog-Emitting Dipoles _: Driving a Fourth Preferred Embodiment - Illumination View A fifth preferred embodiment of a pulse width control unit is a circuit diagram in accordance with one of the present invention. The figure is a signal waveform of a triangular wave signal in a dimming process according to the ninth figure. A pulse width control chart of a sixth preferred embodiment. Fig. 11 is a circuit diagram of a unit according to the present invention. [Main component symbol description] Prior art:

Feedback control circuit 100 conversion circuit 110 LED module 120 input power supply VIN control signal Sc 1 output voltage VOUT ' "Si'll' II 丨'恂 (four) divination; 20 201234914 Inductance Ll transistor switch SW1 rectifier two Pole body κι output capacitor Cl inductor current IL.1 resistor R1 current balance unit 130 current balance terminal D1 ~ Dn voltage detection circuit 140 feedback signal FM, drive power VCC. Pulse width control '蕈元150:: Amplifying unit 152 Compensation unit 154.

Feedback unit 160 reference signal Vrl pulse width control signal Veal pulse width modulation unit 162 drive unit 164 pulse width modulation signal S1 dimming signal DIM The present invention: feedback control circuit 200, 300, 400 conversion circuit 210, 310, 410 Voltage detection circuit 312 LED module 220, 320, 420 Current balancing unit 230, 430 Voltage detection circuit 240, 440 Logic unit 242 201234914 r Retrieving unit 250, 350, 450 Charging unit 252 Comparator 352 Amplifying unit 452 Discharge unit 254 signal superimposing unit 354 compensation unit 454 pulse width control unit 260, 360, 460, 560, 660, 760 pulse width modulation unit 262, 362, 462, 562, 662, 762 drives early elements 264, 364, 464, 564, 664, 764 dimming control unit 266, 366, 466, 566, 666, 766 dimming adjusting unit 270, 370, 470, 570, 670, 770 selecting unit 272, 372, 472 delay trigger unit 772 SR positive and negative 386, 486, 776 level modulation unit 280, 380, 480 reverse gate 281, 282,

Delay unit 382, 482 trigger unit 384, 484 first D-type flip-flop 283 second D-type flip-flop 284 third D-type flip-flop 285 and gate 286 input power VIN control signals Sc2, Sc3, Sc4, Sc5, Sc6, Sc7

Output voltage VOUT

Output current IOUT Inductance L2, L3 Transistor switch SW2, SW3 Rectifier diode K2, K3a, K3b

22 201234914 " Output Capacitor C2, C3 Pole Current IL2 Resistor R3 Current Balance Terminal D1~Dn Feedback Signal Fb2, Fb3, Fb4 Reference Power Supply Vref

Pulse width control signal Vea2, Vea3, Vea4, Vea5, Vea6, Vea7 compensation capacitor C level unit R first current source II first switch SW01 .. first current source 12 second switch SW02

Pulse width modulation signal S2, S3, S4, S5, S6, S7 dimming signal DIM dimming control signal P2, P3, P4, P5, P6, P7 first level signal C0mpl, Comp3, Comp5 second level signal Comp2, Comp4, Comp6 select signals Sel2, Sel3, Sel4 input D Bu D2, D3,

Set terminal S reset terminal R1, R2, R3, R output terminal Φ, Q2, Q3, Q Inverting output terminal Ql', Q2', Q3' Clock control terminal CLIO, CLK2, CLK3 Bridge rectifier BD AC input power VAC transformer T3 current feedback signal IFb3 · Voltage feedback signal VFb3 - · 23 .., 忒i' : , V : Said 201234914 " Current source Is dimming adjustment signal Vr3, Vr4, Vr5, Vr6, Vr7

Clock signal PU drive power supply VCC,

._V.

twenty four

Claims (1)

201234914 " " VII. Patent application scope: 1. A feedback control circuit for controlling a conversion circuit to convert a power source to drive a light-emitting diode module, the light-emitting diode module having at least one light-emitting a diode string and the LED strings are connected in parallel with each other, the feedback control circuit includes: a feedback unit 'receiving a feedback signal representing a state of the LED module to generate a pulse width a control signal, wherein the feedback unit includes a dimming adjustment unit for generating a dimming adjustment signal according to a timing of the dimming signal, and a pulse width control unit, according to the pulse width control signal to generate At least one control signal for controlling the conversion circuit for power conversion; fortunately, the dimming signal is switched between a first state and a second state, and the dimming adjustment signal of the feedback unit is used for the dimming The signal is controlled by the second state: the pulse width control signal is adjusted for a period of time just after the first state is changed, and the duty cycle of the at least one control signal is increased by a predetermined value. The feedback control circuit of the first aspect of the invention, wherein the feedback signal is a current feedback signal representing a current flowing through the LED in the LED module or applied to the illumination One of the output voltages of the diode module is a voltage feedback signal. - The feedback control circuit of claim 2, wherein the feedback unit further comprises a charging unit, a discharge unit and a capacitor The charging unit is coupled to the capacitor for charging the capacitor and the discharging unit is coupled to the capacitor for discharging the electric current to the electric current One of the charging unit and the discharging unit is activated, and when one of the output strings of the pair of light emitting diodes is greater than the predetermined voltage, the charging unit and the other of the discharging units are activated. The feedback unit generates the pulse width control signal based on the potential of the capacitor. 4. The feedback control circuit of claim 2, wherein the feedback order 201234914 r element further comprises an error amplifier, one of the error amplifiers The inverting input terminal receives the dimming adjustment signal and an inverting input terminal receives the feedback signal, and the output end of the error amplifier outputs the pulse width control signal. 5. The feedback according to claim 2 a control circuit, wherein the feedback unit further includes a comparator, the pulse width control unit includes a flip-flop, the comparator receives the dimming adjustment signal and the feedback signal to generate the pulse width control signal accordingly The feedback control circuit of claim 3, wherein the dimming adjustment unit is coupled between the charging unit and the capacitor. . . . 7. Patent Application No. 1 The feedback control circuit of the item, wherein the time period is determined by the feedback unit according to the feedback signal or for a predetermined length of time. The feedback control circuit described in claim 7 of the patent scope, wherein the adjustment The light modulation unit includes a time setting unit for setting the predetermined time length. The processing control circuit of claim 1, wherein the working period of the at least one binary signal is greater than or equal to a predetermined working week of the Lupo 0 t feedback control circuit during the time period. The feedback control circuit includes: a feedback unit π, and receives one of the states representing the LED module, and returns δ to the δ drive unit. %, in order to generate a pulse width control signal; and wherein the dimming signal is cut between a first state and a second state 26 201234914 can be controlled by the control unit in the dimming signal by the second state The conversion to the work of the third control signal is increased - the default value. What is the _ period compared to the pulse? The control circuit, wherein the pulse width signal, and the dimming signal are cycled by the second state, the slope signal is low, and the pulse width g = glass signal and the ship width Pu'er mosquito station is less-controlled The oblique glass 1Z is as a feedback control circuit according to the tenth item of the patent application. The pulse width control unit determines or is based on the back_number, and uses the (four) motion-lighting diode module. The ίίί one-pole module has at least a light-emitting diode string and the light-emitting diode strings are connected in parallel with each other, and the return-light two-pole motion includes: 尤-秘申, two-turn f electric ϊ, the secret light-emitting diode The module receives at least one control message: the touch of the polar body - the coffee _ the illuminance is generated by (four) 丨ϊϊϊΐ ΐ ΐ ' according to the feedback signal, the at least the control signal is subtracted, and according to the dimming signal, the State or - second state; ^ its t ^ control circuit is in the dimming signal for the second state has just been converted to a time period 'adjusting the at least - control signal to the working week H to pay the at least - the control signal has a guard period greater than Or equal to a predetermined duty cycle. For example, the application of the patent | 发光 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光 发光And the at least one control signal, wherein the working period of the at least one control signal is less than the first state in the second state. The optical-emitting body driving circuit according to claim 13 of the patent application, further comprising A voltage detecting circuit is coupled to the sand-emitting diode string to generate the feedback signal according to the potential of the at least one LED string. 28