WO2020001262A1 - Led驱动控制器、led驱动电路及led发光装置 - Google Patents

Led驱动控制器、led驱动电路及led发光装置 Download PDF

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Publication number
WO2020001262A1
WO2020001262A1 PCT/CN2019/090596 CN2019090596W WO2020001262A1 WO 2020001262 A1 WO2020001262 A1 WO 2020001262A1 CN 2019090596 W CN2019090596 W CN 2019090596W WO 2020001262 A1 WO2020001262 A1 WO 2020001262A1
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Prior art keywords
circuit
signal
control signal
overvoltage protection
led
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PCT/CN2019/090596
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English (en)
French (fr)
Inventor
程志强
贾有平
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北京集创北方科技股份有限公司
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Priority to US16/628,005 priority Critical patent/US10952300B2/en
Priority to KR1020197037943A priority patent/KR102279464B1/ko
Publication of WO2020001262A1 publication Critical patent/WO2020001262A1/zh

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
    • H05B45/54—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits in a series array of LEDs
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/32—Pulse-control circuits
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
    • H05B45/59—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits for reducing or suppressing flicker or glow effects
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
    • Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Definitions

  • the present invention relates to the field of electronic technology, and in particular, to an LED drive controller, an LED drive circuit, and an LED light emitting device.
  • LED Light Emitting Diode
  • LED has many advantages such as long service life, small size, low power consumption, and low operating temperature, so it is widely used in LED lighting and LED display products.
  • FIG. 1 shows a circuit diagram of a switching LED driving circuit in the prior art.
  • the LED driving circuit includes a rectifying and filtering circuit 10, a power supply circuit 20, an existing LED driving controller 30 and an output stage circuit 40.
  • the rectifying and filtering circuit 10 includes a rectifying bridge 101 and a first capacitor C1, wherein the rectifying bridge 101 rectifies and filters the input AC voltage AC into a DC bus voltage Vin and stores it in the first capacitor C1.
  • the power supply circuit 20 includes a resistor R and a second capacitor C2.
  • the DC bus voltage Vin charges the second capacitor C2 through the resistor R to provide a stable power supply voltage VCC to the existing LED drive controller 30.
  • the output stage circuit 40 includes an inductor L, a diode D, and a third capacitor C3.
  • the diode D is connected between the DRAIN pin of the LED drive controller 30 and the DC bus voltage Vin.
  • the inductor L is connected to the DRAIN pin of the LED drive controller 30.
  • the third capacitor C3 is connected between the DC bus voltage Vin and the output terminal Vout.
  • the LED load 50 includes a plurality of LEDs connected in series and connected in parallel between the DC bus voltage Vin and the output terminal Vout.
  • the output stage circuit 40 drives the LED load 50 based on the DC power output from the LED drive controller 30.
  • FIG. 2 shows an internal block diagram of the LED drive controller in the prior art
  • FIG. 3 is a working waveform diagram of the LED drive controller 30 in the prior art.
  • the VCC pin of the LED drive controller is a power supply pin for receiving the power supply voltage VCC; the DRAIN pin is connected to the internal switch Q; the CS pin is a sampling pin for collecting the current flowing through the switch Q The current is connected to the sampling resistor Rcs; the GND pin is a ground pin; OVP is an open-circuit protection pin and is connected to the open-circuit protection resistor Rovp.
  • the comparator U1 When the voltage Vcs of the sampling resistor Rcs is greater than the reference voltage Vref, the comparator U1 outputs the first control.
  • the signal S1 is sent to the control circuit.
  • the inductor L provides energy, the inductor current I L cannot jump instantly.
  • the inductor current I L gradually decreases from the peak value Ipk until it decreases to zero.
  • the zero-crossing detection circuit detects that the inductor current I L is zero.
  • the common practice is to detect the off time Toff, and compare it with the internal reference time Tovp. When the off time Toff> Tovp, it works normally; When the off time Toff ⁇ Tovp, an overvoltage protection signal OVP is sent to the control circuit to enter the overvoltage protection mode to prevent the LED from being burned out.
  • the input AC voltage AC is rectified and filtered by the rectifier bridge 101 and the first capacitor C1, it will cause a large ripple on the DC bus voltage Vin, especially when the input voltage is small and the LED voltage is large.
  • the value is close to V LED .
  • the on-time Ton of the switch Q will be large.
  • the frequency range of the sound that can be heard by the average human ear is 20Hz ⁇ 20KHz. If the frequency is not processed, the frequency may be heard by the human ear, which appears as an induction howling phenomenon.
  • the method to solve the inductor howling phenomenon is to add a maximum on-time circuit inside the LED drive controller 30.
  • the switch After the maximum on-time Ton_max has elapsed, the switch will be turned off even if the inductor current IL does not reach the preset threshold Ipk. Tube Q. Because the peak value of the inductor current I L is low, the off time Toff will also be correspondingly shorter than normal. It is likely that Toff ⁇ Tovp will occur, causing the overvoltage protection mode to flash.
  • an object of the present invention is to provide an LED driving controller, an LED driving circuit, and an LED light emitting device, which can prevent the lamp from flashing when it enters an overvoltage protection mode when the voltage input is low and the LED load voltage is high.
  • an LED driving controller including:
  • the power tube has a control terminal, a first terminal, and a second terminal.
  • the control terminal receives the switch control signal.
  • the first terminal is connected to the LED load via an inductor, and the second terminal is grounded via a sampling resistor.
  • a zero-crossing detection circuit the input end of which is connected to the first end of the power tube and used for generating a zero-crossing detection signal
  • a first comparison circuit configured to compare according to a reference voltage and a sampling voltage to generate a first control signal
  • a control circuit is connected to the zero-crossing detection circuit and the comparison circuit, and is configured to generate a switching control signal according to the zero-crossing detection signal and the first control signal, wherein the switching control signal is used to control the power tube On and off;
  • an input terminal of the overvoltage protection circuit is grounded via an overvoltage protection resistor, and is configured to generate an overvoltage protection signal according to an off time provided by the control circuit and a reference voltage;
  • a shielding circuit is provided between the overvoltage protection circuit and the control circuit, and is configured to shield the overvoltage protection signal in an inactive state when the power tube is turned off according to the shielding signal, and reset the overvoltage protection signal when the power tube is turned on.
  • the voltage protection signal is active.
  • the shielding circuit includes:
  • a shielding signal generating circuit configured to generate a shielding signal according to the first control signal and the second control signal
  • a logic circuit is configured to shield the overvoltage protection signal in an inactive state when the power tube is turned off according to the shielding signal, and reset the overvoltage protection signal to be in an effective state when the power tube is turned on.
  • the LED driving controller further includes:
  • the second comparison circuit is configured to generate a second control signal according to the on-time and the maximum on-time provided by the control circuit.
  • the shielding signal is maintained at a high level so that the overvoltage protection signal is in an effective state.
  • the shield signal is maintained at a low level so that the overvoltage protection signal is in an inactive state.
  • the LED driving controller further includes:
  • the maximum time on-time circuit is configured to generate the maximum on-time.
  • the LED driving controller further includes:
  • the leading edge blanking circuit is configured to generate a second control signal according to the switch control signal.
  • the shield signal is high-level during the power tube off-time and low-level during the power-tube on-time, so that the overvoltage protection signal It is in an effective state during the power tube turn-off period and in an inactive state during the power tube turn-on period, so that the overvoltage protection signal is in an effective state during the power tube turn-off period and is in an inactive state during the power tube turn-on period.
  • the shielding signal is maintained at a low level, so that the overvoltage protection signal is in an invalid state.
  • the shielding signal generating circuit includes a first NOR gate, a second NOR gate, and a NOT gate,
  • the first input terminal of the first NOR gate receives the second control signal, the second input terminal is connected to the output terminal of the second NOR gate, and the output terminal is connected to the first input terminal of the second NOR gate;
  • a first input terminal of the second NOR gate is connected to an output terminal of the first NOR gate.
  • the second input terminal receives the first control signal, and the output terminal outputs a shield signal.
  • the logic circuit is a NAND gate.
  • the first comparison circuit includes:
  • a reference voltage generating unit configured to generate a reference voltage according to a power supply voltage
  • the first comparison unit is configured to generate a first control signal according to the reference voltage and the sampling voltage.
  • the over-voltage protection circuit includes:
  • the second comparison unit is configured to generate an overvoltage protection signal according to an off time and a reference time provided by the control circuit.
  • an LED driving circuit including the LED driving controller as described above.
  • an LED light emitting device including the LED driving circuit and the LED load as described above.
  • the LED driving controller, LED driving circuit and LED lighting device provided by the present invention are provided with a shielding circuit between the overvoltage protection circuit and the control circuit, and the shielding circuit enables the overvoltage protection circuit according to the shielding signal when the power tube is turned off. It is in an invalid state to prevent the LED driving circuit from entering the over-voltage protection mode and flickering when the input voltage is low and the LED load voltage is high. Further, when the power tube is turned on, the shielding circuit is reset, so that the overvoltage protection circuit works normally, and a burn-out phenomenon is avoided.
  • FIG. 1 shows a circuit diagram of a switching LED driving circuit in the prior art
  • FIG. 2 shows an internal block diagram of the LED driving controller shown in FIG. 1;
  • FIG. 3 is a schematic diagram showing the working waveforms of the LED driving controller shown in FIG. 1;
  • FIG. 3 is a schematic diagram showing the working waveforms of the LED driving controller shown in FIG. 1;
  • FIG. 4 shows an internal block diagram of the LED driving controller provided by the first embodiment of the present invention
  • FIG. 5 shows a circuit diagram of a shielding circuit of an LED driving controller according to a first embodiment of the present invention
  • FIG. 6a and FIG. 6b respectively show signal waveform diagrams of the LED driving controller according to the second embodiment of the present invention during operation
  • FIG. 7 shows an internal block diagram of an LED driving controller according to a second embodiment of the present invention.
  • FIG. 8 is a circuit diagram of a shielding circuit of an LED driving controller according to a second embodiment of the present invention.
  • FIG. 9a and FIG. 9b respectively show signal waveform diagrams of the LED driving controller in operation according to the second embodiment of the present invention.
  • FIG. 4 shows an internal block diagram of the LED driving controller provided by the first embodiment of the present invention.
  • the LED driving controller 30 includes a power transistor Q, a zero-crossing detection circuit 31, a first comparison circuit 32, a control circuit 33, an over-voltage protection circuit 34, and a shielding circuit 35.
  • the power transistor Q has a control terminal, a first terminal, and a second terminal.
  • the control terminal receives the switch control signal SQ.
  • the first terminal is connected to the LED load via the inductor L, and the second terminal is grounded via the sampling resistor Rcs.
  • the LED drive controller 30 includes a power supply port Vcc for supplying a power supply voltage to the LED drive controller 30; a ground port GND to provide internal ground for the LED chip; a DRAIN port via the inductor L and the LED load
  • the sampling port CS is connected to the ground port GND via a sampling resistor Rcs for sampling the inductor current I L of the inductor L, where the voltage drop generated by the sampling resistor Rcs is taken as the sampling voltage Vcs; the overvoltage protection port OVP is connected to the ground terminal GND via an overvoltage protection resistor Rovp.
  • the first end of the power tube is connected to the DRAIN port, and the second end is connected to the sampling port CS.
  • the input terminal of the zero-crossing detection circuit 31 is connected to the first end of the power tube, and is used to generate a zero-crossing detection signal ZCD.
  • the input terminal of the zero-crossing detection circuit 31 is connected to the first terminal of the power transistor Q, that is, connected to the DRAIN port of the LED drive controller 30, and is used to detect the inductor current I L of the inductor L and generate Zero detection signal.
  • the control circuit 33 controls the power transistor Q to be turned on according to the switch control signal SQ generated by the zero-crossing detection signal.
  • the first comparison circuit 32 is configured to compare the reference voltage and the sampling voltage to generate a first control signal.
  • the first comparison circuit 32 includes a reference voltage generating unit 321 and a first comparison unit 322, wherein the reference voltage generating unit 321 is configured to generate a reference voltage Vref according to a power supply voltage Vcc; the first comparison unit 322.
  • the first input terminal receives the reference voltage Vref
  • the second input terminal receives the sampling voltage Vcs
  • the output terminal outputs the first control signal S1.
  • the switching signal SQ generated by the control circuit 33 according to the first control signal S1 is an off signal, and the power transistor Q is controlled to be turned off.
  • a control circuit 33 is connected to the zero-crossing detection circuit 31 and the first comparison circuit 32, and is configured to generate a switching control signal SQ according to the zero-crossing detection signal ZCD and the first control signal S1, wherein the switch controls The signal SQ is used to control the on and off of the power transistor Q.
  • An input terminal of the overvoltage protection circuit 34 is grounded via an overvoltage protection resistor Rovp, and is configured to generate an overvoltage protection signal OVP according to the off time Toff provided by the control circuit 33 and the reference voltage Vovp.
  • the overvoltage protection circuit 34 includes a reference time unit 341 and a second comparison unit 342, wherein the reference time unit 321 is configured to generate a reference time Tovp according to the reference voltage Vovp; the second comparison unit 342 is configured to The off-time Toff and the reference time Tovp provided by the control circuit generate an over-voltage protection signal OVP.
  • Toff ⁇ Tovp the control circuit 33 controls the power tube Q to be turned off according to the overvoltage protection signal OVP, and enters an overvoltage protection mode.
  • a shielding circuit 35 is provided between the overvoltage protection circuit 34 and the control circuit 33, and is used to make the overvoltage protection signal OVP in an inactive state according to the shielding signal SS when the power tube Q is turned off, and to turn on the power tube Q When resetting, the over-voltage protection signal OVP is in an active state.
  • the LED driving controller includes a shielding signal generating circuit 351 and a logic circuit 352.
  • the shielding signal generating circuit 351 is configured to generate a signal according to a first control signal S1 and a second control signal S2.
  • logic circuit 352 is used to shield the overvoltage protection signal OVP in an inactive state when the power transistor Q is turned off according to the shield signal SS, and reset the overvoltage protection signal OVP when the power transistor Q is turned on Is active.
  • the shielding signal generating circuit 351 includes two NOR gates NOR1 and NOR2 and a NOT gate; wherein a first input terminal of the NOR gate NOR1 receives a second control signal S2, and a second input The terminal is connected to the output terminal of the NOR gate NOR2, and the output terminal is connected to the first input terminal of the NOR gate NOR2; the second input terminal of the NOR gate NOR2 receives the first control signal S1, and the output terminal outputs the shielding signal SS.
  • the logic circuit 352 includes a NAND gate NAND. The first input terminal of the NAND gate NAND receives the shielding signal SS, the second input terminal receives the overvoltage protection signal OVP, and the output terminal is connected to the control circuit 33.
  • the LED driving controller further includes a second comparison circuit 36 and a maximum time on-time circuit 37.
  • the second comparison circuit 36 is configured to generate a second control signal S2 according to the on-time Ton and the maximum on-time Ton-max provided by the control circuit.
  • the maximum on-time circuit 37 is configured to generate the maximum on-time Ton-max. When Ton> Ton-max, the second comparison circuit 36 outputs a second control signal S2.
  • FIG. 6a and FIG. 6b respectively show signal waveform diagrams of the LED driving controller in operation according to the first embodiment of the present invention.
  • the shielding signal SS is maintained at a high level, so that the overvoltage protection signal OVP is in an effective state.
  • the LED load is in a light load state
  • the inductor current is relatively large
  • the sampling voltage Vcs may be larger than the reference voltage Vref.
  • the first control signal S1 is a high-level pulse, and the on-time of the power tube is always It is shorter than the maximum on-time (Ton ⁇ Ton-max), so the second control signal S2 remains low. At this time, the shielding signal SS remains high, and the overvoltage protection signal OVP is always in an effective state.
  • the mask signal SS is maintained at a low level, so that the overvoltage protection signal OVP is in an invalid state.
  • the LED load is in a heavy load state, and the inductor current is relatively small, so that the sampling voltage Vcs is not greater than the reference voltage Vref. Therefore, if the first control signal S1 is kept at a low level, the power tube is turned on.
  • the second control signal S2 is a high-level pulse. At this time, the shielding signal SS is kept at a low level, and the overvoltage protection signal OVP is always in an invalid state.
  • the first embodiment of the present invention provides an LED drive controller.
  • a shielding circuit is provided between the overvoltage protection circuit and the control circuit, and the shielding circuit makes the overvoltage protection circuit in an inactive state according to the shielding signal when the power tube is turned off to prevent When the input voltage is low and the LED load voltage is high, the LED driving circuit enters the overvoltage protection mode and blinks. Further, when the power tube is turned on, the shielding circuit is reset, so that the overvoltage protection circuit works normally, and a burn-out phenomenon is avoided.
  • FIG. 7 shows an internal block diagram of an LED driving controller according to a second embodiment of the present invention.
  • the LED driving controller 30 includes a power transistor Q, a zero-crossing detection circuit 31, a first comparison circuit 32, a control circuit 33, an over-voltage protection circuit 34, and a shielding circuit 35.
  • the power transistor Q has a control terminal, a first terminal, and a second terminal.
  • the control terminal receives the switch control signal SQ.
  • the first terminal is connected to the LED load via the inductor L, and the second terminal is grounded via the sampling resistor Rcs.
  • the LED drive controller 30 includes a power supply port Vcc for supplying a power supply voltage to the LED drive controller 30; a ground port GND to provide internal ground for the LED chip; a DRAIN port via the inductor L and the LED load
  • the sampling port CS is connected to the ground port GND via a sampling resistor Rcs for sampling the inductor current I L of the inductor L, where the voltage drop generated by the sampling resistor Rcs is taken as the sampling voltage Vcs; the overvoltage protection port OVP is connected to the ground terminal GND via an overvoltage protection resistor Rovp.
  • the first end of the power tube is connected to the DRAIN port, and the second end is connected to the sampling port CS.
  • the input terminal of the zero-crossing detection circuit 31 is connected to the first end of the power tube, and is used to generate a zero-crossing detection signal ZCD.
  • the input terminal of the zero-crossing detection circuit 31 is connected to the first terminal of the power transistor Q, that is, connected to the DRAIN port of the LED drive controller 30, and is used to detect the inductor current I L of the inductor L and generate Zero detection signal.
  • the control circuit 33 controls the power transistor Q to be turned on according to the switch control signal SQ generated by the zero-crossing detection signal.
  • the first comparison circuit 32 is configured to compare the reference voltage and the sampling voltage to generate a first control signal.
  • the first comparison circuit 32 includes a reference voltage generating unit 321 and a first comparison unit 322, wherein the reference voltage generating unit 321 is configured to generate a reference voltage Vref according to a power supply voltage Vcc; the first comparison unit 322.
  • the first input terminal receives the reference voltage Vref
  • the second input terminal receives the sampling voltage Vcs
  • the output terminal outputs the first control signal S1.
  • the switching signal SQ generated by the control circuit 33 according to the first control signal S1 is an off signal, and the power transistor Q is controlled to be turned off.
  • a control circuit 33 is connected to the zero-crossing detection circuit 31 and the first comparison circuit 32, and is configured to generate a switching control signal SQ according to the zero-crossing detection signal ZCD and the first control signal S1, wherein the switch controls The signal SQ is used to control the on and off of the power transistor Q.
  • An input terminal of the overvoltage protection circuit 34 is grounded via an overvoltage protection resistor Rovp, and is configured to generate an overvoltage protection signal OVP according to the off time Toff provided by the control circuit 33 and the reference voltage Vovp.
  • the overvoltage protection circuit 34 includes a reference time unit 341 and a second comparison unit 342, wherein the reference time unit 321 is configured to generate a reference time Tovp according to the reference voltage Vovp; the second comparison unit 342 is configured to The off-time Toff and the reference time Tovp provided by the control circuit generate an over-voltage protection signal OVP.
  • Toff ⁇ Tovp the control circuit 33 controls the power tube Q to be turned off according to the overvoltage protection signal OVP, and enters an overvoltage protection mode.
  • a shielding circuit 35 is provided between the overvoltage protection circuit 34 and the control circuit 33, and is used to make the overvoltage protection signal OVP in an inactive state according to the shielding signal SS when the power tube Q is turned off, and to turn on the power tube Q When resetting, the over-voltage protection signal OVP is in an active state.
  • the shielding circuit 35 includes a shielding signal generating circuit 351 and a logic circuit 352, wherein the shielding signal generating circuit 351 is configured to generate a shielding signal SS according to a first control signal S1 and a second control signal S2;
  • the logic circuit 352 is configured to shield the overvoltage protection signal OVP in an inactive state when the power transistor Q is turned off according to the shielding signal SS, and reset to make the overvoltage protection signal OVP in an effective state when the power transistor Q is turned on.
  • the shielding signal generating circuit 351 includes two NOR gates NOR1 and NOR2 and a NOT gate; wherein a first input terminal of the NOR gate NOR1 receives a second control signal S2, and a second input The terminal is connected to the output terminal of the NOR gate NOR2, and the output terminal is connected to the first input terminal of the NOR gate NOR2; the second input terminal of the NOR gate NOR2 receives the first control signal S1, and the output terminal outputs the shielding signal SS.
  • the logic circuit 352 includes a NAND gate NAND. The first input terminal of the NAND gate NAND receives the shielding signal SS, the second input terminal receives the overvoltage protection signal OVP, and the output terminal is connected to the control circuit 33.
  • the LED driving controller further includes a leading edge blanking circuit 38 for generating a second control signal S2 according to the switch control signal SQ.
  • the leading-edge blanking circuit 38 When the power transistor Q is turned on, the leading-edge blanking circuit 38 generates a high-level pulse.
  • leading-edge blanking circuit 38 is further configured to generate a second control signal S2 according to the zero-crossing detection signal ZCD.
  • FIG. 9a and FIG. 9b respectively show signal waveform diagrams of the LED driving controller in operation according to the second embodiment of the present invention.
  • the shielding signal is high-level during the power tube off-time and low-level during the power-tube on-time.
  • the voltage protection signal is in an effective state during the power tube is off, and is in an inactive state during the power tube on period.
  • the LED load is in a light load state, the inductor current is relatively large, and the sampling voltage Vcs may be larger than the reference voltage Vref.
  • the first control signal S1 is a high-level pulse, which causes the power tube Q to be turned off;
  • the second control signal S2 is a high-level pulse generated at the moment when the power tube Q is turned on, and the high-level pulse of the first control signal S1 is located at the moment when the power tube Q is turned off, and the high-level pulse of the second control signal S2 is It is located at the turn-on moment of the power tube Q.
  • the shield signal SS is high during the power tube Q is off, and is low during the power tube Q is on, so that the overvoltage protection signal OVP is in an effective state during the power tube Q off, and the power tube Q It is in an inactive state during conduction.
  • the shielding signal SS is kept at a low level, so that the overvoltage protection signal OVP is in an inactive state.
  • the LED load is in a heavy load state, and the inductor current is relatively small, and the sample voltage Vcs will not be larger than the reference voltage Vref. Therefore, the first control signal S1 is kept at a low level, and the second control signal S2 is at a power level.
  • a second embodiment of the present invention provides an LED drive controller.
  • a shield circuit is provided between the overvoltage protection circuit and the control circuit, and the shield circuit makes the overvoltage protection circuit in an invalid state according to the shield signal when the power tube is turned off, preventing When the input voltage is low and the LED load voltage is high, the LED driving circuit enters the overvoltage protection mode and blinks. Further, when the power tube is turned on, the shielding circuit is reset, so that the overvoltage protection circuit works normally, and a burn-out phenomenon is avoided.
  • the present invention also provides an LED driving circuit including the LED driving controller as described above.
  • the invention also provides an LED light emitting device, which includes the LED driving circuit as described above.

Abstract

公开了一种LED驱动控制器及驱动电路，包括：功率管，具有控制端、第一端和第二端，控制端接收开关控制信号；过零检测电路，用于产生过零检测信号；第一比较电路，用于根据参考电压和采样电压相比较以产生第一控制信号；控制电路，与过零检测电路以及比较电路相连，用于根据过零检测信号以及第一控制信号产生开关控制信号；过压保护电路，用于根据控制电路提供的关断时间以及基准电压产生过压保护信号；屏蔽电路，用于根据屏蔽信号在功率管关断时屏蔽使过压保护信号无效，以及在功率管导通时复位使过压保护信号有效。本发明可以防止在输入电压较低而LED负载电压较高时LED驱动电路进入过压保护模式而闪灯，同时避免出现烧灯现象。

Description

LED驱动控制器、LED驱动电路及LED发光装置
本申请要求了2018年6月27日提交的、申请号为201810678909.0、发明名称为“LED驱动控制器、LED驱动电路及LED发光装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明涉及电子技术领域，特别涉及一种LED驱动控制器、LED驱动电路及LED发光装置。
背景技术
LED(Light Emitting Diode，发光二极管)具有使用寿命长、体积小、功率消耗低、工作温度低等许多优点，因此广泛应用于LED照明以及LED显示产品。
LED灯的亮度与驱动电流相关，相应的驱动方案为线性驱动方案和开关驱动方案。二者分别采用线性调节晶体管的方式和开关控制晶体管的方式调节驱动电流。图1示出了现有技术中开关型LED驱动电路的电路图。如图1所示，所述LED驱动电路包括整流滤波电路10、供电电路20、现有的LED驱动控制器30和输出级电路40。整流滤波电路10包括整流桥101和第一电容C1，其中，所述整流桥101将输入的交流电压AC整流滤波为直流母线电压Vin，并且存储于第一电容C1。供电电路20包括电阻R和第二电容C2，直流母线电压Vin通过电阻R给第二电容C2充电，以向现有的LED驱动控制器30提供稳定的供电电压VCC。输出级电路40包括电感L、二极管D和第三电容C3，二极管D连接在LED驱动控制器30的DRAIN引脚和直流母线电压Vin之间，电感L连接在LED驱动控制器30的DRAIN引脚以及输出级电路40的输出端Vout之间；第三电容C3连接在直流母线电压Vin和输出端Vout之间。LED负载50包括多个串联的LED，并联连接在直流母线电压Vin和输出端Vout之间。输出级电路40根据LED驱动控制器30输出的直流电驱动LED负载50。
图2示出了现有技术中的LED驱动控制器的内部框图；图3是现有技术中的LED驱动控制器30的工作波形图。所述LED驱动控制器的VCC引脚为供电引脚，用于接收供电电压VCC；DRAIN引脚连接至内部的开关管Q；CS引脚为采样引脚，用于采集流经开关管Q的电流，与采样电阻Rcs相连；GND引脚为接地引脚；OVP为开路保护引脚，与开路保护电阻Rovp相连。当LED驱动控制器30内部集成的开关管Q导通时，对电感L进行储能，电感电流I L一直上升，到 采样电阻Rcs的电压Vcs大于基准电压Vref时，比较器U1输出第一控制信号S1至控制电路，控制电路在接收到第一控制信号后，控制开关管Q关断，电感电流上升到预设阈值Ipk，LED驱动控制器30的导通时间Ton为T on＝L*Ipk/(Vin-V LED)，其中，Ipk＝Vref/Rcs，V LED为LED负载50两端的电压，即Vin与Vout之间的电压差；当LED驱动控制器30内部集成的开关管Q关断时，电感L提供能量，电感电流I L无法瞬间跳变，因此，电感电流I L从峰值Ipk逐步减小，直至减小为零，此时过零检测电路检测到电感电流I L为零时，则发送一过零检测信号ZCD至控制电路，使得控制电路发生复位，控制开关管Q导通，LED驱动控制器30的关断时间Toff为T off＝L*Ipk/V LED。也就是说，当电感电流I L被充电至一预设阈值Ipk时，LED驱动控制器30关断开关管Q，当电感电流I L放电至零时，LED驱动控制器30导通开关管Q，以这样的方式重复信号。因此，LED驱动控制器30内部的开关管Q在开关状态之间反复切换，以使得LED驱动控制器30工作在临界导通模式下。
由于没有辅助绕组的存在，无法直接检测LED灯两端的电压，目前通用的做法是检测关断时间Toff，与内部的基准时间Tovp进行比较，当关断时间Toff＞Tovp时，正常工作；当关断时间Toff＜Tovp时，向控制电路发送过压保护信号OVP，进入过压保护模式，防止将LED烧坏。
由于输入的交流电压AC经过整流桥101和第一电容C1整流滤波后，会使直流母线电压Vin产生较大的纹波，尤其是当输入电压较小且LED的电压较大时，Vin的最小值接近V LED，此时，开关管Q的导通时间Ton会很大。一般人耳能听到的声音频率范围为20Hz～20KHz，如果不进行处理的话，该频率可能会被人耳听到，表现为电感啸叫现象。解决电感啸叫现象的方法是在LED驱动控制器30内部增加最大导通时间电路，当经过最大导通时间Ton_max时间后，即使电感电流I L仍未达到预设阈值Ipk，也会关断开关管Q。由于电感电流I L的峰值较低，关断时间Toff的时间也会比正常相应减小，很可能会出现Toff＜Tovp，导致进入过压保护模式而闪灯。
发明内容
鉴于上述问题，本发明的目的在于提供一种LED驱动控制器、LED驱动电路及LED发光装置，在电压输入较低且LED负载电压较高时防止进入过压保护模式而闪灯。
根据本发明的第一方面，提供一种LED驱动控制器，包括：
功率管，具有控制端、第一端和第二端，控制端接收开关控制信号，第一端经由电感与LED负载相连，第二端经由采样电阻接地；
过零检测电路，其输入端连接所述功率管的第一端，用于产生过零检测信号；
第一比较电路，用于根据参考电压和采样电压相比较以产生第一控制信号；
控制电路，与所述过零检测电路以及比较电路相连，用于根据所述过零检测信号以及所述第一控制信号产生开关控制信号，其中，所述开关控制信号用于控制功率管的导通与关断；过压保护电路，其输入端经由过压保护电阻接地，用于根据所述控制电路提供的关断时间以及基准电压产生过压保护信号；
屏蔽电路，设置在过压保护电路和控制电路之间，用于根据屏蔽信号在功率管关断时屏蔽使所述过压保护信号处于无效状态，以及在功率管导通时复位使所述过压保护信号处于有效状态。
优选地，所述屏蔽电路包括：
屏蔽信号产生电路，用于根据第一控制信号和第二控制信号产生屏蔽信号；
逻辑电路，用于根据屏蔽信号在功率管关断时屏蔽使所述过压保护信号处于无效状态，以及在功率管导通时复位使所述过压保护信号处于有效状态。
优选地，所述LED驱动控制器还包括：
第二比较电路，用于根据所述控制电路提供的导通时间和最大导通时间产生第二控制信号。
优选地，当第一控制信号为高电平脉冲，第二控制信号保持低电平时，则屏蔽信号保持高电平，使过压保护信号处于有效状态。
优选地，当第一控制信号保持低电平，第二控制信号为高电平脉冲时，则屏蔽信号保持低电平，使过压保护信号处于无效状态。
优选地，所述LED驱动控制器还包括：
最大时间导通电路，用于产生所述最大导通时间。
优选地，所述LED驱动控制器还包括：
前沿消隐电路，用于根据所述开关控制信号产生第二控制信号。
优选地，当第一控制信号和第二控制信号均为高电平脉冲时，屏蔽信号在功率管关断期间为高电平，在功率管导通期间为低电平，使得过压保护信号在功率管关断期间处于有效状态，在功率管导通期间处于无效状态，使得过压保护信号在功率管关断期间处于有效状态，在功率管导通期间处于无效状态。
优选地，当第一控制信号保持低电平，第二控制信号为高电平脉冲时，屏蔽信号保持低电平，使过压保护信号处于无效状态。
优选地，所述屏蔽信号产生电路包括第一或非门、第二或非门和非门，
其中，第一或非门的第一输入端接收第二控制信号，第二输入端与第二或非门的输出端相连，输出端与第二或非门的第一输入端相连；
第二或非门的第一输入端与第一或非门的输出端相连，第二输入端接收第一控制信号，输出 端输出屏蔽信号。
优选地，所述逻辑电路为与非门。
优选地，所述第一比较电路包括：
参考电压产生单元，用于根据供电电压产生参考电压；
第一比较单元，用于根据参考电压和采样电压产生第一控制信号。
优选地，所述过压保护电路包括：
基准时间单元，用于根据基准电压产生基准时间；
第二比较单元，用于根据所述控制电路提供的关断时间和基准时间产生过压保护信号。
根据本发明的另一方面，提供一种LED驱动电路，包括如上所述的LED驱动控制器。
根据本发明的第三方面，提供一种LED发光装置，包括如上所述的LED驱动电路和LED负载。
本发明提供的LED驱动控制器、LED驱动电路及LED发光装置，在过压保护电路和控制电路之间设置有屏蔽电路，所述屏蔽电路在功率管关断时根据屏蔽信号使过压保护电路处于无效状态，防止在输入电压较低而LED负载电压较高时LED驱动电路进入过压保护模式而闪灯。进一步地，在功率管导通时对屏蔽电路进行复位，使得过压保护电路正常工作，避免出现烧灯现象。
附图说明
通过以下参照附图对本发明实施例的描述，本发明的上述以及其他目的、特征和优点将更为清楚，在附图中：
图1示出了现有技术中开关型LED驱动电路的电路图；
图2示出了图1所示的LED驱动控制器的内部框图；
图3示出了图1所示的LED驱动控制器的工作波形示意图；
图4示出了本发明第一实施例提供的LED驱动控制器的内部框图；
图5示出了根据本发明第一实施例提供的LED驱动控制器的屏蔽电路的电路图；
图6a和图6b分别示出了本发明第二实施例提供的LED驱动控制器工作时的信号波形图；
图7示出了本发明第二实施例提供的LED驱动控制器的内部框图；
图8示出了本发明第二实施例提供的的LED驱动控制器的屏蔽电路的电路图；
图9a和图9b分别示出了本发明第二实施例提供的LED驱动控制器工作时的信号波形图。
具体实施方式
以下将参照附图更详细地描述本发明的各种实施例。在各个附图中，相同的元件采用相同或类似的附图标记来表示。为了清楚起见，附图中的各个部分没有按比例绘制。
下面结合附图和实施例，对本发明的具体实施方式作进一步详细描述。
图4示出了本发明第一实施例提供的LED驱动控制器的内部框图。如图4所示，所述LED驱动控制器30包括功率管Q、过零检测电路31、第一比较电路32、控制电路33、过压保护电路34和屏蔽电路35。
其中，功率管Q具有控制端、第一端和第二端，控制端接收开关控制信号SQ，第一端经由电感L与LED负载相连，第二端经由采样电阻Rcs接地。
在本实施例中，LED驱动控制器30包括供电端口Vcc，用于向所述LED驱动控制器30提供供电电压；地端口GND，为LED芯片提供内部接地；DRAIN端口，经由电感L与LED负载相连；采样端口CS，经由采样电阻Rcs与地端口GND相连，用于对电感L的电感电流I L进行采样，其中，将流经采样电阻Rcs产生的压降作为采样电压Vcs；过压保护端口OVP，经由过压保护电阻Rovp与地端口GND相连。功率管的第一端与DRAIN端口相连，第二端与采样端口CS相连。
过零检测电路31，其输入端连接所述功率管的第一端，用于产生过零检测信号ZCD。
在本实施例中，过零检测电路31其输入端与功率管Q的第一端连接，即与LED驱动控制器30的DRAIN端口相连，用于检测电感L的电感电流I L，并产生过零检测信号。其中，当检测到所述电感电流I L为0时，控制电路33根据所述过零检测信号产生的开关控制信号SQ为导通信号，控制所述功率管Q导通。
第一比较电路32用于根据参考电压和采样电压相比较以产生第一控制信号。
在本实施例中，所述第一比较电路32包括参考电压产生单元321和第一比较单元322，其中，所述参考电压产生单元321用于根据供电电压Vcc产生参考电压Vref；第一比较单元322，其第一输入端接收参考电压Vref，第二输入端接收采样电压Vcs，输出端输出第一控制信号S1。当采样电压Vcs大于参考电压Vref时，控制电路33根据第一控制信号S1产生的开关控制信号SQ为关断信号，控制所述功率管Q关断。
控制电路33，与所述过零检测电路31以及第一比较电路32相连，用于根据所述过零检测信号ZCD以及所述第一控制信号S1产生开关控制信号SQ，其中，所述开关控制信号SQ用于控制功率管Q的导通与关断。
过压保护电路34，其输入端经由过压保护电阻Rovp接地，用于根据所述控制电路33提供的关断时间Toff以及基准电压Vovp产生过压保护信号OVP。
在本实施例中，所述过压保护电路34包括基准时间单元341和第二比较单元342，其中，基 准时间单元321用于根据基准电压Vovp产生基准时间Tovp；第二比较单元342用于根据所述控制电路提供的关断时间Toff和基准时间Tovp产生过压保护信号OVP。当Toff＜Tovp时，控制电路33根据过压保护信号OVP控制功率管Q关断，进入过压保护模式。
屏蔽电路35，设置在过压保护电路34和控制电路33之间，用于在功率管Q关断时根据屏蔽信号SS使所述过压保护信号OVP处于无效状态，以及在功率管Q导通时复位使所述过压保护信号OVP处于有效状态。
LED驱动控制器如图5所示，所述屏蔽电路35包括屏蔽信号产生电路351和逻辑电路352，其中，所述屏蔽信号产生电路351用于根据第一控制信号S1和第二控制信号S2产生屏蔽信号SS；逻辑电路352用于根据屏蔽信号SS在功率管Q关断时屏蔽使所述过压保护信号OVP处于无效状态，以及在功率管Q导通时复位使所述过压保护信号OVP处于有效状态。
在一个优选地实施例中，所述屏蔽信号产生电路351包括两个或非门NOR1和NOR2以及非门NOT；其中，或非门NOR1的第一输入端接收第二控制信号S2，第二输入端与或非门NOR2的输出端相连，输出端与或非门NOR2的第一输入端相连；或非门NOR2的第二输入端接收第一控制信号S1，输出端输出屏蔽信号SS。逻辑电路352包括与非门NAND，其中，与非门NAND的第一输入端接收屏蔽信号SS，第二输入端接收过压保护信号OVP，输出端与控制电路33相连。
在一个优选地实施例中，所述LED驱动控制器还包括第二比较电路36和最大时间导通电路37。其中，第二比较电路36，用于根据所述控制电路提供的导通时间Ton和最大导通时间Ton-max产生第二控制信号S2。最大时间导通电路37，用于产生所述最大导通时间Ton-max。当Ton＞Ton-max时，第二比较电路36输出第二控制信号S2。
图6a和图6b分别示出了本发明第一实施例提供的LED驱动控制器工作时的信号波形图。如图6a所示，当第一控制信号S1为高电平脉冲，第二控制信号S2保持低电平时，则屏蔽信号SS保持高电平，使过压保护信号OVP处于有效状态。这种情况下，LED负载为轻载状态，电感电流比较大，会出现采样电压Vcs大于参考电压Vref的情况，因此，第一控制信号S1为高电平脉冲，且功率管的导通时间一直小于最大导通时间即(Ton＜Ton-max)，所以第二控制信号S2保持低电平。此时屏蔽信号SS保持高电平，一直使过压保护信号OVP处于有效状态。
如图6b所示，当第一控制信号S1保持低电平，第二控制信号S2为高电平脉冲时，则屏蔽信号SS保持低电平，使过压保护信号OVP处于无效状态。这种情况下，LED负载为重载状态，电感电流比较小，不会出现采样电压Vcs大于参考电压Vref的情况，因此，第一控制信号S1保持低电平，则会出现功率管的导通时间大于最大导通时间的情况，所以第二控制信号S2为高电平脉冲。此时屏蔽信号SS保持低电平，一直使过压保护信号OVP处于无效状态。
本发明第一实施例提供LED驱动控制器，在过压保护电路和控制电路之间设置有屏蔽电路，所述屏蔽电路在功率管关断时根据屏蔽信号使过压保护电路处于无效状态，防止在输入电压较低而LED负载电压较高时LED驱动电路进入过压保护模式而闪灯。进一步地，在功率管导通时对屏蔽电路进行复位，使得过压保护电路正常工作，避免出现烧灯现象。
图7示出了本发明第二实施例提供的LED驱动控制器的内部框图。如图7所示，所述LED驱动控制器30包括功率管Q、过零检测电路31、第一比较电路32、控制电路33、过压保护电路34和屏蔽电路35。
其中，功率管Q具有控制端、第一端和第二端，控制端接收开关控制信号SQ，第一端经由电感L与LED负载相连，第二端经由采样电阻Rcs接地。
在本实施例中，LED驱动控制器30包括供电端口Vcc，用于向所述LED驱动控制器30提供供电电压；地端口GND，为LED芯片提供内部接地；DRAIN端口，经由电感L与LED负载相连；采样端口CS，经由采样电阻Rcs与地端口GND相连，用于对电感L的电感电流I L进行采样，其中，将流经采样电阻Rcs产生的压降作为采样电压Vcs；过压保护端口OVP，经由过压保护电阻Rovp与地端口GND相连。功率管的第一端与DRAIN端口相连，第二端与采样端口CS相连。
过零检测电路31，其输入端连接所述功率管的第一端，用于产生过零检测信号ZCD。
在本实施例中，过零检测电路31其输入端与功率管Q的第一端连接，即与LED驱动控制器30的DRAIN端口相连，用于检测电感L的电感电流I L，并产生过零检测信号。其中，当检测到所述电感电流I L为0时，控制电路33根据所述过零检测信号产生的开关控制信号SQ为导通信号，控制所述功率管Q导通。
第一比较电路32用于根据参考电压和采样电压相比较以产生第一控制信号。
在本实施例中，所述第一比较电路32包括参考电压产生单元321和第一比较单元322，其中，所述参考电压产生单元321用于根据供电电压Vcc产生参考电压Vref；第一比较单元322，其第一输入端接收参考电压Vref，第二输入端接收采样电压Vcs，输出端输出第一控制信号S1。当采样电压Vcs大于参考电压Vref时，控制电路33根据第一控制信号S1产生的开关控制信号SQ为关断信号，控制所述功率管Q关断。
控制电路33，与所述过零检测电路31以及第一比较电路32相连，用于根据所述过零检测信号ZCD以及所述第一控制信号S1产生开关控制信号SQ，其中，所述开关控制信号SQ用于控制功率管Q的导通与关断。
过压保护电路34，其输入端经由过压保护电阻Rovp接地，用于根据所述控制电路33提供的关断时间Toff以及基准电压Vovp产生过压保护信号OVP。
在本实施例中，所述过压保护电路34包括基准时间单元341和第二比较单元342，其中，基准时间单元321用于根据基准电压Vovp产生基准时间Tovp；第二比较单元342用于根据所述控制电路提供的关断时间Toff和基准时间Tovp产生过压保护信号OVP。当Toff＜Tovp时，控制电路33根据过压保护信号OVP控制功率管Q关断，进入过压保护模式。
屏蔽电路35，设置在过压保护电路34和控制电路33之间，用于在功率管Q关断时根据屏蔽信号SS使所述过压保护信号OVP处于无效状态，以及在功率管Q导通时复位使所述过压保护信号OVP处于有效状态。
如图8所示，所述屏蔽电路35包括屏蔽信号产生电路351和逻辑电路352，其中，所述屏蔽信号产生电路351用于根据第一控制信号S1和第二控制信号S2产生屏蔽信号SS；逻辑电路352用于根据屏蔽信号SS在功率管Q关断时屏蔽使所述过压保护信号OVP处于无效状态，以及在功率管Q导通时复位使所述过压保护信号OVP处于有效状态。
在一个优选地实施例中，所述屏蔽信号产生电路351包括两个或非门NOR1和NOR2以及非门NOT；其中，或非门NOR1的第一输入端接收第二控制信号S2，第二输入端与或非门NOR2的输出端相连，输出端与或非门NOR2的第一输入端相连；或非门NOR2的第二输入端接收第一控制信号S1，输出端输出屏蔽信号SS。逻辑电路352包括与非门NAND，其中，与非门NAND的第一输入端接收屏蔽信号SS，第二输入端接收过压保护信号OVP，输出端与控制电路33相连。
在一个优选地实施例中，所述LED驱动控制器还包括前沿消隐电路38，用于根据所述开关控制信号SQ产生第二控制信号S2。当功率管Q导通时，前沿消隐电路38会产生一个高电平的脉冲。
在一个优选地实施例中，所述前沿消隐电路38还用于根据所述过零检测信号ZCD产生第二控制信号S2。
图9a和图9b分别示出了本发明第二实施例提供的LED驱动控制器工作时的信号波形图。
如图9a所示，当第一控制信号和第二控制信号均为高电平脉冲时，屏蔽信号在功率管关断期间为高电平，在功率管导通期间为低电平，使得过压保护信号在功率管关断期间处于有效状态，在功率管导通期间处于无效状态。这种情况下，LED负载为轻载状态，电感电流比较大，会出现采样电压Vcs大于参考电压Vref的情况，因此，第一控制信号S1为高电平脉冲，使得功率管Q关断；第二控制信号S2是在功率管Q导通的瞬间产生的高电平脉冲，且第一控制信号S1的高电平脉冲位于功率管Q的关断瞬间，第二控制信号S2的高电平脉冲位于功率管Q的导通瞬间。此时屏蔽信号SS在功率管Q关断期间为高电平，在功率管Q导通期间为低电平，使得过压保护信号OVP在功率管Q关断期间处于有效状态，在功率管Q导通期间处于无效状态。
如图9b所示，当第一控制信号S1保持低电平，第二控制信号S2为高电平脉冲时，则屏蔽信号SS保持低电平，使过压保护信号OVP处于无效状态。这种情况下，LED负载为重载状态，电感电流比较小，不会出现采样电压Vcs大于参考电压Vref的情况，因此，第一控制信号S1保持低电平，第二控制信号S2是在功率管Q导通的瞬间产生的高电平脉冲。此时屏蔽信号SS保持低电平，一直使过压保护信号OVP处于无效状态。
本发明第二实施例提供LED驱动控制器，在过压保护电路和控制电路之间设置有屏蔽电路，所述屏蔽电路在功率管关断时根据屏蔽信号使过压保护电路处于无效状态，防止在输入电压较低而LED负载电压较高时LED驱动电路进入过压保护模式而闪灯。进一步地，在功率管导通时对屏蔽电路进行复位，使得过压保护电路正常工作，避免出现烧灯现象。
本发明还提供了一种LED驱动电路，包括如上所述的LED驱动控制器。
本发明还提供了一种LED发光装置，包括如上所述的LED驱动电路。
依照本发明的实施例如上文所述，这些实施例并没有详尽叙述所有的细节，也不限制该发明仅为所述的具体实施例。显然，根据以上描述，可作很多的修改和变化。本说明书选取并具体描述这些实施例，是为了更好地解释本发明的原理和实际应用，从而使所属技术领域技术人员能很好地利用本发明以及在本发明基础上的修改使用。本发明仅受权利要求书及其全部范围和等效物的限制。

Claims (15)

  1. 一种LED驱动控制器，其特征在于，包括：
    功率管，具有控制端、第一端和第二端，控制端接收开关控制信号，第一端经由电感与LED负载相连，第二端经由采样电阻接地；
    过零检测电路，其输入端连接所述功率管的第一端，用于产生过零检测信号；
    第一比较电路，用于根据参考电压和采样电压相比较以产生第一控制信号；
    控制电路，与所述过零检测电路以及比较电路相连，用于根据所述过零检测信号以及所述第一控制信号产生开关控制信号，其中，所述开关控制信号用于控制功率管的导通与关断；过压保护电路，其输入端经由过压保护电阻接地，用于根据所述控制电路提供的关断时间以及基准电压产生过压保护信号；
    屏蔽电路，设置在过压保护电路和控制电路之间，用于根据屏蔽信号在功率管关断时屏蔽使所述过压保护信号处于无效状态，以及在功率管导通时复位使所述过压保护信号处于有效状态。
  2. 根据权利要求1所述的LED驱动控制器，其特征在于，所述屏蔽电路包括：
    屏蔽信号产生电路，用于根据第一控制信号和第二控制信号产生屏蔽信号；
    逻辑电路，用于根据屏蔽信号在功率管关断时屏蔽使所述过压保护信号处于无效状态，以及在功率管导通时复位使所述过压保护信号处于有效状态。
  3. 根据权利要求2所述的LED驱动控制器，其特征在于，还包括：
    第二比较电路，用于根据所述控制电路提供的导通时间和最大导通时间产生第二控制信号。
  4. 根据权利要求3所述的LED驱动控制器，其特征在于，当第一控制信号为高电平脉冲，第二控制信号保持低电平时，则屏蔽信号保持高电平，使过压保护信号处于有效状态。
  5. 根据权利要求3所述的LED驱动控制器，其特征在于，当第一控制信号保持低电平，第二控制信号为高电平脉冲时，则屏蔽信号保持低电平，使过压保护信号处于无效状态。
  6. 根据权利要求4所述的LED驱动控制器，其特征在于，还包括：
    最大时间导通电路，用于产生所述最大导通时间。
  7. 根据权利要求2所述的LED驱动控制器，其特征在于，还包括：
    前沿消隐电路，用于根据所述开关控制信号产生第二控制信号。
  8. 根据权利要求7所述的LED驱动控制器，其特征在于，当第一控制信号和第二控制信号均为高电平脉冲时，屏蔽信号在功率管关断期间为高电平，在功率管导通期间为低电平，使得过压保护信号在功率管关断期间处于有效状态，在功率管导通期间处于无效状态。
  9. 根据权利要求7所述的LED驱动控制器，其特征在于，当第一控制信号保持低电平，第二控制信号为高电平脉冲时，屏蔽信号保持低电平，使过压保护信号处于无效状态。
  10. 根据权利要求2所述的LED驱动控制器，其特征在于，所述屏蔽信号产生电路包括第一或非门、第二或非门和非门，
    其中，第一或非门的第一输入端接收第二控制信号，第二输入端与第二或非门的输出端相连，输出端与第二或非门的第一输入端相连；
    第二或非门的第一输入端与第一或非门的输出端相连，第二输入端接收第一控制信号，输出端输出屏蔽信号。
  11. 根据权利要求2所述的LED驱动控制器，其特征在于，所述逻辑电路为与非门。
  12. 根据权利要求1所述的LED驱动控制器，其特征在于，所述第一比较电路包括：
    参考电压产生单元，用于根据供电电压产生参考电压；
    第一比较单元，用于根据参考电压和采样电压产生第一控制信号。
  13. 根据权利要求1所述的LED驱动控制器，其特征在于，所述过压保护电路包括：
    基准时间单元，用于根据基准电压产生基准时间；
    第二比较单元，用于根据所述控制电路提供的关断时间和基准时间产生过压保护信号。
  14. 一种LED驱动电路，包括整流滤波电路、输出级电路以及如权利要求1-13中任一项所述的LED驱动控制器。
  15. 一种LED发光装置，其特征在于，包括如权利要求14所述的LED驱动电路和LED负载。
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Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108650744A (zh) 2018-06-27 2018-10-12 北京集创北方科技股份有限公司 Led驱动控制器、led驱动电路及led发光装置
CN109921624B (zh) * 2019-03-26 2024-02-23 杭州士兰微电子股份有限公司 一种开关电源控制器、开关电源及其过压检测方法
CN112466249A (zh) * 2020-12-17 2021-03-09 北京集创北方科技股份有限公司 一种led驱动电路
CN112888104B (zh) * 2021-01-22 2023-08-08 杭州士兰微电子股份有限公司 Led驱动电路及其驱动控制器和控制方法
CN112837646B (zh) * 2021-02-02 2022-12-06 海信视像科技股份有限公司 显示装置及其控制方法
CN112996189B9 (zh) * 2021-04-09 2022-07-19 杭州士兰微电子股份有限公司 Led驱动装置及其驱动控制电路
CN113301690B (zh) * 2021-04-14 2023-04-28 深圳深爱半导体股份有限公司 照明灯驱动芯片和驱动电路
CN114007305A (zh) * 2021-10-09 2022-02-01 深圳南云微电子有限公司 一种控制方法及控制器
CN113873719B (zh) * 2021-11-30 2022-03-08 深圳赫飞物联科技有限公司 一种调光控制电路
CN114552529B (zh) * 2022-01-28 2022-10-21 绵阳惠科光电科技有限公司 过压保护电路、装置、显示面板及显示器

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106714367A (zh) * 2016-11-16 2017-05-24 深圳市必易微电子有限公司 恒流电路及其恒流控制器
CN106786450A (zh) * 2016-11-25 2017-05-31 北京集创北方科技股份有限公司 过压保护电路及其控制方法和led驱动装置
CN108650744A (zh) * 2018-06-27 2018-10-12 北京集创北方科技股份有限公司 Led驱动控制器、led驱动电路及led发光装置
CN208300087U (zh) * 2018-06-27 2018-12-28 北京集创北方科技股份有限公司 Led驱动控制器、led驱动电路及led发光装置

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9148013B1 (en) * 2014-03-11 2015-09-29 Grenergy Opto Inc. Control methods for over voltage protection and relevant power controllers
CN105992435B (zh) * 2015-02-12 2019-03-15 上海含英微电子有限公司 抗干扰led过压保护模块以及抗干扰led过压保护系统
CN204497985U (zh) * 2015-04-13 2015-07-22 杭州士兰微电子股份有限公司 Led驱动电路及其开关电源控制器
US9917503B2 (en) * 2015-05-13 2018-03-13 Fairchild Korea Semiconductor Ltd. Overcurrent protection circuit and power factor correction circuit comprising the same
JP6711679B2 (ja) * 2016-04-15 2020-06-17 ローム株式会社 ワイヤレス受電装置の同期整流回路、その制御回路、制御方法、ワイヤレス受電装置および受電制御回路、電子機器
CN205810342U (zh) 2016-05-24 2016-12-14 北京集创北方科技股份有限公司 Led显示驱动系统和led显示屏
US10128740B1 (en) * 2016-09-06 2018-11-13 Universal Lighting Technologies Dynamic AC impedance stabilization in a flyback LED driver
CN106338643B (zh) * 2016-10-14 2023-08-18 上海灿瑞微电子有限公司 Led驱动芯片过压检测电路及方法
CN206136406U (zh) 2016-10-31 2017-04-26 北京集创北方科技股份有限公司 Led驱动装置及其保护电路
CN206136405U (zh) 2016-10-31 2017-04-26 北京集创北方科技股份有限公司 Led驱动装置及其线电压补偿电路
CN106535396B (zh) * 2016-11-04 2018-04-13 辉芒微电子（深圳）有限公司 一种抗干扰的恒流led驱动电路
CN107690213A (zh) * 2017-10-17 2018-02-13 无锡恒芯微科技有限公司 非隔离低压不闪烁led驱动电路
CN109921624B (zh) * 2019-03-26 2024-02-23 杭州士兰微电子股份有限公司 一种开关电源控制器、开关电源及其过压检测方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106714367A (zh) * 2016-11-16 2017-05-24 深圳市必易微电子有限公司 恒流电路及其恒流控制器
CN106786450A (zh) * 2016-11-25 2017-05-31 北京集创北方科技股份有限公司 过压保护电路及其控制方法和led驱动装置
CN108650744A (zh) * 2018-06-27 2018-10-12 北京集创北方科技股份有限公司 Led驱动控制器、led驱动电路及led发光装置
CN208300087U (zh) * 2018-06-27 2018-12-28 北京集创北方科技股份有限公司 Led驱动控制器、led驱动电路及led发光装置

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CN108650744A (zh) 2018-10-12
US10952300B2 (en) 2021-03-16

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