90results about How to "High precision constant current" patented technology

The invention relates to a light-dimmer driving circuit. The light-dimmer driving circuit comprises a power supply input module, a transformer, a current output driving module, a pulse width modulation (PWM) module, an input voltage sampling module, an output voltage sampling module and a control center, wherein the power supply input module is mainly used for rectification and filtering of an input voltage signal, the transformer is used for voltage reduction of the voltage signal output by the power supply input module, the current output driving module is used for driving of current output according to the voltage signal which is transformed, the PWM module is used for adjusting output power of the current output driving module according to a control signal in the control center, the input voltage sampling module is used for sampling of the input voltage signal and transmitting the input voltage signal to the control center, the output voltage sampling module is used for sampling of output voltage and transmitting the output voltage to the control center, and the control center is used for controlling a PWM signal according to an input voltage sampling signal, an output voltage sampling signal and an input current signal. According to the light-dimmer driving circuit, due to the fact that the control center is used for controlling the PWM signal according to the input voltage sampling signal, the output voltage sampling signal and the input current signal, the output power of the current output driving module is enabled to change evenly, flicker-free light adjusting is achieved, constant current output is achieved, and range of the light adjusting is wide.

The invention provides a current reference generation circuit which comprises the following parts: a first multiplier module which receives a rectification voltage waveform signal of a switch power supply and an output signal of an average electric current loop, and generates a sine half-wave signal which has same frequency and phase with the rectification voltage waveform signal and changes with the output signal of the average electric current loop; a second multiplier module which inputs the sine half-wave signal and a control signal and generates a pulse signal; the average electric current loop which compares an average value of the pulse signal with a set average electric current loop reference signal. The current reference generation circuit can generate a reference signal followed by a primary current signal of a self-adapting switch power supply main circuit and provides the reference signal to a high power factor constant current switch power supply control circuit, and the reference signal carries out self-adapting adjustment with circuit input output condition change so as to satisfy a requirement of secondary constant current output. Simultaneously, based on the current reference generation circuit, the invention realizes a primary controlled high power factor constant current switch power supply control circuit and a control method thereof.

The invention discloses a constant current source system for average current mode control, and a control method thereof. The constant current source system comprises an inductor L1 and a sampling resistor RCS which are connected in series with an external connection load, a freewheeling diode D1 which is connected in parallel with the load, the inductor L1 and the sampling resistor RCS, and a power switch which is used for controlling charging and discharging states of the inductor. The constant current source system further comprises an error amplifier, a loop compensation unit, a first voltage current converter, an oscillator, a PWM modulation unit, a latch trigger unit, a driving unit, a first resistor R1 which is connected with the positive input end of the error amplifier and a reference source, and a second resistor R2 which is connected with the negative input end of the error amplifier and one end of the sampling circuit. According to the constant current source system for the average current mode control, and the control method thereof, brought forward by the invention, the output current precision of a constant current source system can be improved, at the same time, the work frequency is fixed, and the design of the constant current source system can be simplified.

The invention discloses a control circuit of a switch power supply and a method thereof. The method comprises the following steps: a constant-current control module generates and outputs a control signal for controlling an output current of the switch power supply according to feedback information on a pin FB and a pin CS, adjusts a power-on duty ratio of a power transistor, and adjusts an output current IO of a power supply system as a constant value; a constant-current precision compensation module adjusts a circuit calculation parameter of the constant-current control module and a sampling and holding module according to the feedback information on the pin FB and the pin CS, so that the output constant-current precision is not influenced by the change of a working mode and / or the change of an input condition; a timer determines a moment when the voltage VFB on the pin FB reaches a peak value; and a pressure control oscillator adjusts the switching frequency of a power transistor according to a control signal outputted by the constant-current control module and an output signal of the timer, so that the switch power supply works at a QR mode or a CCM mode, and when the output voltage is changed, the QR mode is kept unchanged or the current continuous depth of the CCM mode is kept similar.

The invention relates to an LED (light-emitting diode) multi-lamp distributed group drive system. The system comprises a front-end high-power isolated constant voltage source and a plurality of back-end low-power non-isolated constant current sources. The front-end high-power isolated constant voltage source comprises an input rectifying and filtering circuit, a power supply management chip, a primary clamping circuit of a transformer, a high-frequency transformer, an output rectifying and filtering circuit and an output voltage sampling, comparing and feedback circuit. The input end of each back-end low-power non-isolated constant current source is connected with the output end of the front-end high-power isolated constant voltage source, and stable direct current voltage output from the front end is transformed to required direct current through a constant current circuit so as to realize the single-lamp constant current drive of a small LED lamp. The LED multi-lamp distributed group drive system disclosed by the invention has the advantages of simple structure, small volume, high constant current precision, high reliability, high power factor, high efficiency and the like.

The invention relates to a primary edge current reference generating circuit and a primary edge current reference generating method for a high power factor constant-current switch power supply. The conventional primary edge current reference generating circuit is complicated. An input end of a first multiplier is used as an input end of the primary edge current reference generating circuit; an input end of a conduction angle detection circuit is used as another input end of the primary edge current reference generating circuit, and the output end of the conduction angle detection circuit is connected with another input end of the first multiplier; the output end of the first multiplier is used as an input end of a current loop; another input end of the current loop is used as the other input end of the primary edge current reference generating circuit; the output end of the current loop is connected with an input end of a second multiplier; another input end of the second multiplier is connected with the input end of the conduction angle detection circuit; and the output end of the second multiplier is used as the output end of the primary edge current reference generating circuit. Sampling hold is not required, so that the error caused by sample hold is eliminated, and the constant-current precision of the output current is improved.

The invention discloses a constant current control system for a continuous current mode (CCM) and a discontinuous conduct mode (DCM) of a primary-side feedback flyback power supply. The control system comprises a current detection module, an output feedback module, a current computation module, an error computation module, a PID module, a PWM module and a drive module; the control system is connected with a controlled switch power supply to form a closed loop; the current detection module and the output feedback module collect basic parameters for achieving a constant current algorithm; the current computation module computes an average current of a primary-side inductor at a switch-on stage of the switch, computes an average current of secondary output currents according to a turns ratio relation between input and output, and works out an output current by averaging integrals of the current on time, the output value executes a compensation algorithm in the digital PID module, a compensation value is transmitted to a PWM module, an appropriate duty ratio is output by the drive module, and thus high precision constant current of the digital power supply is controlled.

The invention provides a high-power-factor low-harmonic-distortion constant current circuit and device. The circuit comprises a front-level circuit and a rear-level circuit which are coupled mutually, wherein the front-level circuit is a boost-buck circuit used for correcting a power factor, the rear-level circuit is a buck circuit used for direct current-direct current conversion, and moreover the front-level circuit and the rear-level circuit share the same switching tube and the same bus capacitor. Compared with a two-level structure, the devices are fewer, and cost is lower; compared with a single-level buck structure, the output load current ripple is smaller, and the constant current circuit is higher in power factor and lower in total harmonic distortion.

The invention discloses a constant current control system for the output current of a primary-side feedback flyback power supply converter. Based on the conventional constant current control strategy, Ts compensation, Tr compensation, and primary-side peak current compensation are added, constant current processing of digital PI compensation is also combined, and two modes of PWM and PFM are employed for control. Without considering some compensation, under the PWM mode, the switch-on time is reduced with the reduction of a load, and the deviation of the output current from the rated current is larger and larger with the reduction of the load; under the PFM mode, the switch-on time is maintained unchanged, and the deviation of the output current from the rated current is maintained unchanged. According to the system, the constant current precision can finally reach + / -2%, and the constant current characteristic of the flyback converter is improved.

The invention discloses a closed-loop control circuit and method for an LED constant current drive circuit and belongs to the technical field of circuit control. The closed-loop control circuit comprises an output average current sampling unit, an output average current reference voltage unit, an error amplifier unit, a comparator unit, an inductance zero current detection unit, a valley bottom conduction detection unit and a logic and drive unit. According to the closed-loop control circuit for the LED constant current drive circuit, LED output average current sampling voltage average value is allowed to be equal to the output average current reference voltage through the closed-loop control mode, thereby realizing constant-current control of LED output average current, and improving precision of the LED output constant current; and a system can automatically carry out corresponding adjustment according to the change of application conditions through closed loop feedback, thereby effectively improving linear and load adjustment capability of the LED output current and improving anti-interference capability and stability of an LED driving power source.

The invention belongs to the technical field of constant current driving, and provides an LED lighting device, an LED driving circuit and a switch power source driving chip of the LED driving circuit. The switch power source driving chip comprises a switch device, a logic control module, a first voltage comparison module and a degaussing detection module. The input end of the first voltage comparison module is connected with the input end of an output stage circuit, the output end of the first voltage comparison module is connected with the first input end of the logic control module, the first input end of the degaussing detection module is connected with the voltage output end of an output circuit, the second input end of the degaussing detection module is connected with the output end of the logic control module, the output end of the degaussing detection module is connected with the second input end of the logic control module, and the switching frequency of the switch device is adjusted by the logic control module according to control signals output by the first voltage comparison module and the degaussing detection module. Compared with the prior art, the LED lighting device, the LED driving circuit and the switch power source driving chip are high in constant current accuracy, simple in circuit structure and low in manufacturing cost.

The invention provides a digital constant current controller based on flyback primary side feedback. The digital constant current controller comprises an auxiliary winding output voltage sampling state machine, a demagnetizing time Td compensation module, a bidirectional counter module, a primary side peak current Ip, pk(n) compensation module, a primary side peak current threshold value setting module and a switch signal control module. The digital constant current controller controls a flyback converter to enable the flyback converter to work in a discontinuous conduction mode (DCM), guarantees that the primary side peak value is constant in each switch period through frequency pulse modulation (PFM), and also guarantees that the ratio of the demagnetizing time to the switch period is constant so that digital constant current is realized. Based on the flexibility of digital control, the digital constant current controller provides demagnetizing time compensation and compensates for the delay of demagnetizing time sampling, thereby improving the constant current accuracy. A novel primary side peak value compensation method is provided for the delay in a flyback system, so that the primary side current compensation accuracy is improved and the linearity of output current is higher.

The invention discloses a constant current control device for a switching power supply. A gradient detection module is used for detecting the gradient of voltage on a current sampling resistor of a power supply circuit and converting the gradient into corresponding gradient voltage; voltage compensation module is used for adding the gradient voltage with the voltage of the Vref0 pin of the voltage compensation module to obtain the voltage of the Vref pin of the voltage compensation module; the voltage of the Vref pin of the voltage compensation module is taken as the threshold voltage of a turn-off comparator; the other end of the turn-off comparator is connected with voltage Vcs on the sampling resistor; and the threshold voltage is compared with the voltage Vcs on the sampling resistor, and a control signal is output to a reset signal of an R-S trigger to trigger a driving circuit and turn off a switch tube. Due to the adoption of the constant current control device, the size of a circuit system can be reduced, and the reliability of the system is improved. Constant output during input of different line voltages is ensured, and the constant current can be ensured to output during variation of a transformer Lp of the circuit.

The invention is suitable for the field of power supply, and provides a switch direct-current boosted circuit, a boosted device and an LED illuminating system. The switch direct-current boosted circuit comprises an inductor L1, an inductor L2, a diode D, a capacitor C, a resistor R1, a resistor R2, a MOS tube Q and a switch control unit. Due to the addition of the new inductor in the switch direct-current boosted circuit, the problems of large switch loss, small amplitude of voltage rise and the like in the prior art are solved, so that the switch direct-current boosted circuit improves the work efficiency and the amplitude of output voltage rise.

The invention discloses an LED constant-current driving circuit of multi-path self-adaptive loads. The LED constant-current driving circuit comprises a booster circuit providing positive electrode driving voltage for LED string lamps, a control circuit, a closed loop constant-current mirror driving circuit and a sampling circuit. The closed loop constant-current mirror driving circuit comprises an operational amplifier, power MOS transistors and current limiting resistors R1. The output end of the booster circuit is connected with the positive electrodes of each path of LED string lamps, the negative electrodes of each path of LED string lamps are connected with a drain electrode of one corresponding power MOS transistor, the gate electrode of each power MOS transistor is connected with the output end of the operational amplifier, the source electrode of each power MOS transistor is grounded through one current limiting resistor R1, and one end, connected with the corresponding power MOS transistor, of each current limiting resistor R1 is connected with the reverse input end of the operational amplifier. The output end of the closed loop constant-current mirror driving circuit is connected with the sampling circuit, the control circuit is respectively connected with the sampling circuit and the booster circuit, and the control circuits controls the output voltage of the booster circuit according to the voltage value acquired by the sampling circuit. The LED constant-current driving circuit is high in constant-current precision and capable of automatically regulating the driving voltage and driving multiple paths of LED string lamps at the same time.

The invention discloses a frequency-flicker-free LED filament lamp comprising a linear constant-current drive power supply and an LED luminous body. The drive power supply is composed of an over-current protection unit, a rectifier and filter unit, a linear constant-current unit, a constant-current filter unit, and a frequency flicker elimination unit used for converting the output current of the constant-current filter unit into direct current without current ripple. AC mains power is connected into the input end of the over-current protection unit. The output end of the over-current protection unit is connected with the input end of the rectifier and filter unit. The output end of the rectifier and filter unit is connected with the input end of the linear constant-current unit. The output end of the linear constant-current unit is connected with the input end of the constant-current filter unit. The output end of the constant-current filter unit is connected with the input end of the frequency flicker elimination unit. The output end of the frequency flicker elimination unit is connected with the LED luminous body. The advantage lies in that because of the introduction of the frequency flicker elimination unit, current ripple of constant current is eliminated, the precision of constant current is high, and therefore, there is no frequency flicker during light emission of the LED high-voltage filament in the LED luminous body.

The invention discloses a bridgeless electrolytic-capacitor-free low-ripple-wave high-power constant-current power supply of an LED lamp. The bridgeless electrolytic-capacitor-free low-ripple-wave high-power constant-current power supply of the LED lamp comprises an alternating-current power supply circuit, a control circuit, a coupling-out circuit and a ripple wave restraining circuit. The alternating-current power supply circuit comprises a constant-current drive chip U1, a constant-current drive chip U2, an alternating-current positive half-wave current loop and an alternating-current negative half-wave current loop, wherein the constant-current drive chip U1 and the constant-current drive chip U2 are controlled by the positive half-wave and the negative half-wave of an alternating-current power supply Uin. The current of the alternating-current positive half-wave current loop and the current of the alternating-current negative half-wave current loop both flow through a primary winding N11 and a primary winding N12 of a magnetic integration transformer TR so that an induced voltage can be generated on a secondary winding NV1 and a secondary winding NV2, and then the working voltage of the constant-current drive chip U1 and the working voltage of the constant-current drive chip U2 are provided through the control circuit. An induced secondary current is generated on a center post secondary winding N2 and is output to the loaded LED lamp through the coupling-out circuit. The ripple wave restraining circuit restrains current ripple waves. According to the bridgeless electrolytic-capacitor-free low-ripple-wave high-power constant-current power supply of the LED lamp, a bridge rectifier and an electrolytic capacitor are not adopted, so that the electric power is increased, the reliability is improved, the drive capability of the chips is improved through expanded current, the working temperature of the chips is lowered, the service life of the chips is prolonged, the constant-current precision is high, the current ripple waves are small, the LED lamp does not flicker, and the circuits meet the environmental-friendliness principle.

The invention discloses an LED linear constant current soft start drive circuit comprising a rectification circuit, a work loop circuit, a constant current control circuit, a voltage detection circuit, a soft start circuit and an external control circuit. Very simple circuit design is adopted for solving a complex technical problem. The LED linear constant current soft start drive circuit is advantaged by simple circuit, EMI-free property, high constant current precision, capability of tolerating a large voltage fluctuation range, and the like; a temperature compensation control function, a soft start function and an external light modulation function are fulfilled; intelligent control and wireless Internet of Things connection of LED lamps can be conveniently realized; comprehensive properties of a driver are improved while costs are lowered greatly; a special-purpose integrated LED drive chip can be made, layout design is simplified, manufacture costs of an integrated circuit are greatly lowered, and functions and performance reach a grade which can only be achieved via complex circuit design.

The invention discloses a transformer secondary winding zero current detecting circuit used for an LED driving power source. The zero current detecting circuit comprises a transformer auxiliary winding unit, a resistor voltage divider unit, a negative edge detecting unit, a current sampling unit, a constant-current control unit and a logic and driving unit. The transformer auxiliary winding unit is used for sampling voltages of the two ends of a transformer secondary winding, the resistor voltage divider unit is used for dividing the sampled voltages and inputting the sampled voltages into a control chip, and the negative edge detecting unit is used for performing negative edge detecting on the waveform of the input voltage and generating a zero current detecting signal. The current sampling unit is used for sampling peak value currents of a transformer primary winding, the constant-current control unit is used for performing constant-current control over output currents output by the LED driving power source, and the logic and driving unit is used for performing logic control over output signals of the constant-current control unit, then driving a power switch tube and controlling the negative edge detecting unit. The LED driving power source has a very good effect of outputting constant currents, and meanwhile an ideal load regulation and linear regulation can be achieved.

The invention provides an LED constant-current unit comprising a voltage reference source circuit, an overvoltage protection circuit, a constant-current circuit and a dual-OP-AMP (dual operational amplifiers) chip (U1). The constant-current circuit comprises a MOSFET (metal oxide semiconductor field-effect transistor) (Q1). The voltage reference source circuit is used for generating three reference voltages; one reference voltage is used as operating voltage of the dual-OP-AMP circuit (U1), another reference voltage is used as reference voltage of the overvoltage protection circuit, and the remaining reference voltage is used as reference voltage of the constant-current circuit. The overvoltage protection circuit is used for detecting input voltage and the corresponding reference voltage and comparing output high-low levels to control off of the MOSFET (Q1). The constant-current circuit is used for detecting circuit current and the corresponding reference voltage and comparing output high-low levels to adjust output current of the MOSFET (Q1). The LED constant-current unit has the advantages that the circuits are simple, the cost is low, efficiency is high, EMI (electromagnetic interference) is avoided, constant-current precision is high, and temperature drift is small.

The invention discloses an online integration high-precision constant current source. The online integration high-precision constant current source comprises an industrial frequency transformer, a rectifying and filtering circuit, a constant current control circuit, a constant current power circuit and an output filter circuit. Isolated voltage reduction is realized by utilizing the industrial frequency transformer, output voltage can be linearly regulated by utilizing an operational amplifier and a triode so as to regulate output current for realizing constant current, and short-circuit constant current can be realized by utilizing positive and negative power supply of an amplifier. A linear regulation circuit adopts a pass transistor linear amplification principle control technology, and an AC (Alternating Current) voltage reduction circuit adopts a stable and firm online industrial frequency transformer regulation technology. The online integration high-precision constant current source disclosed by the invention has the characteristics that the power grid adaptability is strong, the output voltage stability accuracy is high, the output ripple voltage is low, the output current is large, the output power is large, the reliability is high, the environment adaptability is strong, and the like.

The invention discloses a bidirectional cuk circuit-based electrolytic capacitance-free LED driving power supply and a switching method thereof. Circuit topology includes a bridge rectifier circuit, The input side of the bridge rectifier circuit is an AC input. The output side of the bridge rectifier circuit is a flyback transformer T connected in series with a first switching transistor Q1, a bidirectional cuk circuit connected in parallel with the output side of the flyback transformer T, an output filter inductor Lo, an output filter capacitor Co and an LED load. The invention has the advantages of high power factor and high constant current precision. By using bidirectional circuit to deal with the pulsating power difference between input and output power, non-electrolytic capacitor can be used instead of electrolytic capacitor, which prolongs the service life of the whole driving power supply and improves the stability of the system.

The invention discloses a high-accuracy laser remote-sensing numerically-controlled power supply system and a control method. The system comprises a BOOST PFC (power factor correction) module, a chip-isolating power supply module, an MOS (metal oxide semiconductor) driving module, a main circuit voltage reducing module and a control module. The BOOST PFC module is connected with the chip-isolatingpower supply module and the main circuit voltage reducing module. The chip-isolating power supply module is connected with the MOS driving module. The main circuit voltage reducing module is connected with the control module. The control module is connected with the MOS driving module. The MOS driving module is connected with the main circuit voltage reducing module. The high-accuracy laser remote-sensing numerically-controlled power supply system and the control method have the advantages that the problems of low digitization of the laser power sources of semiconductor pumps and low constantcurrent accuracy of low voltage and high currents are solved; the structures of conventional two-stage series circuits are improved, and accordingly, high-accuracy working currents can be provided tolaser remote-sensing semiconductor laser devices; the control method capable of achieving rapid algorithm filtering, high-accuracy control and high-robustness control is provided.

The invention discloses a self-excited oscillation driving circuit which comprises a filtering device, a driving device, a switching device, a sampling device connected with the switching device, and a transformer. The transformer at least comprises a self-excited driving winding. The driving device controls on / off of the switching device. The driving device, the self-excited driving winding, the switching device and the sampling device form a loop. The self-excited oscillation driving circuit is characterized in that the self-excited oscillation driving circuit further comprises a current control device connected into the loop formed by the driving device, the self-excited driving winding, the switching device and the sampling device to further control the switching device.

A primary side feedback switching power supply control chip includes a reference voltage unit, a comparator unit, a voltage monitoring unit, a driving unit, a switch unit and a rectifying unit, the switch power supply control chip omits a self-powered time generator, the self-supply time within a single cycle is determined by the voltage at the voltage feedback pin of the switching power supply control chip. In addition, an energy storage module for supplying power to the switching power supply control chip is connected between a power supply pin and a voltage feedback pin of the switching power supply control chip, so that whether the control system operates in the self-powered mode or the non-self-powered mode, The current is passed through the voltage sampling module, so that the peak current expression of the energy storage transformer module is the same, so that the performance of the control system is not affected in the self-powered mode, the minimum load capacity is strong in the constant voltage mode, the constant current precision is high and the linear adjustment rate is good in the constant current mode.

The invention relates to an intelligent LED driving power supply. The input end of an EMI module is connected with a mains supply, the output end of the EMI module is connected with the input end of a rectifier module, and the output end of the rectifier module is connected with the input end of a filter module. A power conversion module and a controller module are connected with the output end of the filter module. The power conversion module, a rectifier and filter module and a photoelectric isolation module are connected to the controller module. A step-down module, the input end of a sampling module and the input end of a DC / DC module are connected to the power conversion module. The output end of the DC / DC module is connected with an intelligent control module. The intelligent control module and an LED node are connected with the step-down module. An amplification and comparison module and a reference module are connected with the output end of the sampling module. The amplification and comparison module is further connected with the photoelectric isolation module. By adopting the intelligent LED driving power supply, high voltage and low voltage can be isolated safely, the precision of constant current is high, and the lines are concise.

The invention discloses an LED (light-emitting diode) display screen constant-current driving circuit with an optional mirror image ratio. The constant-current driving circuit comprises a reference voltage source circuit, a constant-current adjusting circuit, a voltage sampling circuit, a current mirror image ratio self-adjusting circuit, a current mirror circuit and a display frame data processing circuit, wherein the reference voltage source circuit comprises a seven-loop oscillator and bandgap reference circuit; the constant-current adjusting circuit comprises a comparator, a current offset tube and an external ground resistance; the voltage sampling circuit comprises a differential comparator and a logic processing circuit; the current mirror image ratio self-adjusting circuit comprises a plurality of logic and time sequence circuits; the current mirror circuit comprises a plurality of current mirror image tubes; the display frame data processing circuit comprises a plurality of display frame data processing units; and the output drive channel port of the circuit is provided with a 13V withstand voltage circuit which comprises two NMOS (N-channel metal oxide semiconductor) transistors. The driving circuit provided by the invention has the advantages of increasing the gray levels of the LED display screen, increasing the brightness contrast and solving the withstand problemof the output drive channel port with low cost.

The invention provides an automatic sterilization lamp. The automatic sterilization lamp comprises an ultraviolet sterilization lamp, an illuminating lamp and a control device, wherein the ultraviolet sterilization lamp and the illuminating lamp are respectively connected with the control device. The automatic sterilization lamp is characterized in that the control device comprises a power supply circuit, a main control circuit, a human body sensing circuit, a sterilization lamp drive circuit and an illuminating lamp drive circuit, the sterilization lamp drive circuit and the illuminating lamp drive circuit are respectively connected with the power supply circuit, one end of the main control circuit is connected with the power supply circuit, the other end of the main control circuit is respectively connected with the human body sensing circuit and the illuminating lamp drive circuit, the human body sensing circuit is connected with the sterilization lamp drive circuit, the sterilization lamp drive circuit is connected with the ultraviolet sterilization lamp, and the illuminating lamp drive circuit is connected with the illuminating lamp. The automatic sterilization lamp combines the illuminating lamp and the ultraviolet sterilization lamp together, not only can not injure a human body, but also achieves full automatic control, and furthermore is low in energy consumption, low in cost, and easy to popularize and use.

The invention discloses a high-linearity TRIAC dimming compatible LED drive circuit, which adopts a GaN-based high electron mobility transistor (GaN HEMT) and a drive circuit thereof to replace a traditional silicon-based MOSFET so as to realize a MHz high-frequency working environment. Due to the fact that the frequency is greatly improved, values of filtering capacitance and inductance can be reduced, impact current and current oscillation in a circuit can be greatly reduced, and the TRIAC dimming compatibility is improved. A chip FB pin voltage linear regulation technology and a voltage compensation technology are adopted, and high linearity in the LED dimming process is achieved. Besides, an MCU intelligent control module is used for detecting a conduction angle, providing a compensation signal for a chip FB pin and controlling disconnection of the dummy load at the same time, and loss caused by access of the dummy load is effectively reduced under the condition that it is guaranteed that the conduction current is greater than TRIAC starting ignition current.

The invention discloses an intelligent dimming high-efficiency and constant-current LED drive chip which comprises an EMI filter circuit, a control circuit, a chopper circuit, a flyback transfer circuit and an LED load. The EMI filter circuit, the chopper circuit, the flyback transfer circuit and the LED load are sequentially connected, and the control circuit is connected with the chopper circuit and the flyback transfer circuit. The intelligent dimming high-efficiency and constant-current LED drive chip can detect types and phases of light dimmers through the advanced digital control technique to automatically control the luminance of LEDs, is compatible with various types of light dimmers, is high in constant current accuracy and power factor, has an overtemperature protection function, overvoltage protection function, overcurrent protection function and output current adjustable function and is simple in circuit structure and high in cost performance.