Abstract: A buffer circuit for an LED driver circuit, a LED driver circuit, and a control method, the buffer circuit includes a first control switch connected in series in a rectified input loop and a feedback control module connected to the rectified input loop to obtain a loop current in the rectified input loop for generating a first control signal to the first control switch according to the loop current and a reference signal. The first control switch switches between a fully conducting state and a non-fully-conducting state based on the first control signal and restrains the loop current when the first control switch is in the non-fully-conducting state. The buffer circuit enhances the effect of restraining the current change rate and can effectively restrain current spikes in a circuit, resulting in higher safety and reliability.

Abstract: A power supply circuit and a light-emitting diode (LED) driving system using the power supply circuit are provided. The power supply circuit includes a linear conversion circuit, a first capacitor, and a direct current-direct current (DC-DC) conversion circuit, where an alternating current input signal is rectified to form a first rectified voltage. The linear conversion circuit receives the first rectified voltage and has an output terminal connected to the first capacitor. After the power supply circuit is started, the linear conversion circuit controls the first rectified voltage to charge the first capacitor in a time period when the first rectified voltage is near a trough. The DC-DC conversion circuit receives a first capacitor voltage and performs power conversion to output a supply voltage. At least part of the linear conversion circuit and at least part of the DC-DC conversion circuit can be integrated with an LED driving circuit.

Abstract: An X-capacitor discharge method applied to a switched-mode power supply, wherein the switched-mode power supply comprises an X-capacitor, a rectifier circuit and a switching circuit; the X-capacitor discharge method comprises: arranging a first diode, wherein an anode of the first diode is connected to a first end of the X-capacitor, and a cathode of the first diode is configured as a first node; when it is detected that a voltage of the first node is higher than a first voltage threshold, pulling down the first node through a first sampling current, and performing a timing; and if a time for which the voltage of the first node continues to be higher than the first voltage threshold reaches a first threshold time, pulling down the first node through a first pull-down current. An X-capacitor discharge circuit applied to the switched-mode power supply is provided.

Abstract: A control method of a switching circuit, a control circuit of the switching circuit and the switching circuit are provided. The control circuit includes a slope buffer and a first operational amplifier. The slope buffer receives a first voltage reference, and controls slopes of a rising edge and a falling edge to generate a second voltage reference. The first operational amplifier receives an output feedback voltage and a reference voltage, and performs an operational amplification to obtain a compensation voltage. When the first voltage reference has the falling edge, the reference voltage is coupled to the first voltage reference through a first switch, and the second voltage reference is coupled to an output voltage through a second switch. When the first voltage reference has the rising edge, the reference voltage is coupled to the second voltage reference through a third switch.

Abstract: A dimming method and a dimming circuit for driving LED load are provided. The dimming circuit includes a power stage circuit, and the power stage circuit includes a power switch transistor. After the power stage circuit enters the DCM working mode, it obtains a first integral value according to the inductance current in a switch period of the power switch transistor, and obtains second time according to the first integral value and a duty cycle of a PWM dimming signal; when the switch period reaches the second time, the power switch transistor is controlled to be turned on to start the next switch period; a first upper limit voltage is set to a fixed voltage; the power switch transistor is controlled to be turned off when a sampling signal of the inductance current representing the inductance current of the power stage circuit reaches the first upper limit voltage.

Abstract: The present disclosure relates to a switching power supply, and a control circuit and a control method of the switching power supply. The switching power supply comprises N-phase power conversion circuits, N being an integer greater than or equal to 1. The control circuit comprises a current reference signal generating means and a control means. The current reference signal generating means is configured to obtain an integration signal by integrating an error between a first compensation signal and a first voltage signal, and obtains a current reference signal by adding the integration signal and the first compensation signal. The control means provides control signals for respective ones of the N-phase power conversion circuits in accordance with the current reference signal. The first compensation signal represents a difference information between an output feedback signal of the switching power supply and a predetermined reference voltage.

Abstract: A synchronous rectification control circuit and method, and a flyback switched-mode power supply (SMPS) are provided. A voltage adjustment circuit is used to adjust a value of a first voltage signal that represents an output voltage, such that a voltage-second product of a difference between the output voltage and a drain-source voltage of a secondary-side synchronous rectifier can be zeroed in time in a transient process, and no false accumulation occurs. In this way, when a primary-side transistor switch is turned on, the secondary-side synchronous rectifier is turned off, to avoid a case in which the primary-side transistor switch and the secondary-side synchronous rectifier are simultaneously turned on.

Abstract: An analog-to-digital converter includes a D/A conversion circuit, a comparator, and a logic control module. An input signal is sampled and held to obtain a sampling signal. The D/A conversion circuit receives the sampling signal and a reference voltage signal, and an output terminal of the D/A conversion circuit outputs a first voltage signal. The output terminal of the D/A conversion circuit is coupled to at least one input terminal of the comparator. An output terminal of the comparator is coupled to an input terminal of the logic control module, and the logic control module controls the D/A conversion circuit to adjust the first voltage signal according to a comparison result of the comparator. When the number of comparisons of the comparator reaches preset digits of the D/A conversion circuit, a data output terminal of the logic control module outputs a data signal corresponding to the input signal.

Abstract: An inductive current simulation circuit of a switching circuit, an inductive current simulation method of the switching circuit, and a switched-mode power supply are provided. The inductive current simulation method includes the following steps: based on an error amplification circuit, performing, by the error amplification circuit, an error amplification on a first sampling signal representing a current of a synchronous rectifier and a second sampling signal representing an inductive current simulation signal when the synchronous rectifier is turned on to obtain an error amplification signal; and reconstructing an inductive current according to the error amplification signal when the synchronous rectifier is turned on and a first current when a main power transistor is turned on to obtain the inductive current simulation signal.

Abstract: A flyback switching circuit and control method thereof is disclosed, by setting a reference value greater than zero configured for controlling a turn-off time of a first transistor of the flyback switching circuit, a drain-source voltage of a main power transistor of the flyback switching circuit is consistent with the reference value greater than zero before the main power transistor is turned on, so that a turn-on power consumption of the main power transistor is reduced and a system efficiency is improved.

Abstract: Disclosed is an LED driver circuit, a multi-wire communication device and a method for an LED display system. The device comprises a controller providing at least one of a configuration data packet, a brightness data packet, and a display data packet; the LED driver circuits, wherein the LED driver circuits are cascaded to provide a first data channel using first data ports and second data ports, the LED driver circuits are connected in parallel to provide a second data channel using third data ports. The device relays an enable signal or an address data packet stage by stage using the first data channel, transmit at least one of the configuration data packet, the brightness data packet and the display data packet in parallel using the second data channel. The number of the cascaded LED driver circuits can be infinite, the number of data wires is reduced, data rate is increased.

Abstract: Disclosed is a semiconductor device and a manufacturing method, comprising: forming a pad oxide layer and a silicon nitride layer on a substrate; etching the silicon nitride layer into a plurality of segments; forming an oxide layer, having an up-and-down wave shape, by performing a traditional thermal growth field oxygen method on the semiconductor device by use of the plurality of segments serving as forming-assisted structures; performing traditional processes on the semiconductor device having an up-and-down wavy semiconductor surface, to form a gate oxide layer, a polysilicon layer, and to form a source region and a drain region by implantation The semiconductor device having an up-and-down wavy channel region may be formed by a traditional thermal growth field oxygen method, thus the manufacturing processes are simple, the cost is low, and the completed device may have a larger effective channel width and a lower on-state resistance.

Abstract: The present disclosure relates to an electrostatic protection device including an SCR and a manufacturing method thereof. The electrostatic protection device includes a third N+ doped region across an N-type well region and a P-type well region, and a third P+ doped region adjacent to the third N+ doped region. Each of the third N+ doped region and the third P+ doped region has a high doping concentration. In a case that Zener breakdown occurs in a PN junction structure between the third N+ doped region and the third P+ doped region, the SCR is triggered to form a discharge current path. The present disclosure can reduce a trigger voltage of an electrostatic protection device including an SCR, and can provide electrostatic protection devices having different trigger voltages, with high stability and high robustness.

Abstract: The present disclosure relates to a flyback converter and a power supply system. The flyback converter comprises: a transformer; a first switching transistor and a second switching transistor; a first inductor and a first capacitor; and a control circuit. The control circuit includes an under voltage protection module configured to determine an under voltage protection threshold proportional to an output voltage of the flyback converter and to trigger an under voltage protection action of the flyback converter in a case that an input voltage of the flyback converter is less than the under voltage protection threshold. By setting an adaptive under voltage protection threshold, a system-restart phenomenon of the flyback converter after an input power failure or a shutdown may be avoided, and a PFC circuit may be turned off to optimize the standby power consumption and the low load efficiency in fast charging applications using an flyback topology.

Abstract: Disclosed is a semiconductor device and a manufacturing method, comprising: forming a pad oxide layer and a silicon nitride layer on a substrate; etching the silicon nitride layer into a plurality of segments; forming an oxide layer, having an up-and-down wave shape, by performing a traditional thermal growth field oxygen method on the semiconductor device by use of the plurality of segments serving as forming-assisted structures; performing traditional processes on the semiconductor device having an up-and-down wavy semiconductor surface, to form a gate oxide layer, a polysilicon layer, and to form a source region and a drain region by implantation The semiconductor device having an up-and-down wavy channel region may be formed by a traditional thermal growth field oxygen method, thus the manufacturing processes are simple, the cost is low, and the completed device may have a larger effective channel width and a lower on-state resistance.

Abstract: An inductor includes an encapsulation shell with an inductive component encapsulated inside; an input electrode exposed on a surface of the encapsulation shell and configured to receive an alternating voltage; an output electrode exposed on the surface of the encapsulation shell and configured to output a direct current voltage, where the input electrode and the output electrode are electrically isolated by the encapsulation shell; and a metal shield layer asymmetrically covering the surface of the encapsulation shell and electrically connected to the output electrode, where the metal shield layer keeps the input electrode electrically isolated from the output electrode.

Abstract: A dynamic automotive turn signal circuit includes at least one drive control module configured to receive a power supply signal from a body control module (BCM) to start operation, where the drive control module outputs first control signals at different delays through a delay unit; and a light emitting diode (LED) light set connected to the drive control module and lit based on the first control signals. A dynamic automotive turn signal system is further provided. The dynamic automotive turn signal circuit and the dynamic automotive turn signal system uses an external resistor to preset a high-precision delay circuit to realize the function of dynamic flowing turn signals. The external resistor can be used to configure a turn-on delay and a turn-off delay of the internal driver chip, such that the channel turn-on time and turn-off time can be flexibly adjusted.

Abstract: A switched-mode power supply includes a first switch transistor. A drain of the first switch transistor receives an input voltage on a direct current input bus of the switched-mode power supply, and a source is connected to a reference ground. The power supply circuit includes a junction field-effect transistor (JFET), where a drain of the JFET receives the input voltage, a gate is connected to the reference ground, and a source outputs a supply voltage or a supply current. During each switch cycle, the first switch transistor is controlled to be turned off or a drain voltage is controlled to be greater than or equal to a first threshold voltage when the first switch transistor is turned on, such that the supply voltage or the supply current satisfies a drive voltage of the first switch transistor and an operating voltage of a to-be-powered circuit of the switched-mode power supply.

Abstract: A control method and control circuit of a switched-mode power supply, and the switched-mode power supply are provided. An operating mode of the switched-mode power supply is controlled in a first mode and a second mode according to an output feedback signal of the switched-mode power supply. One operating period of the first mode includes a switch period of a boundary conduction mode (BCM), and one operating period of the second mode includes N switch periods of BCMs and a switch period of a discontinuous conduction mode (DCM). The auxiliary switch transistor is turned on once to discharge a parasitic capacitor of the main switch transistor when the switched-mode power supply enters the next operating period from one operating period of the current second mode before the next operating period starts or the switched-mode power supply enters the first mode from the current second mode before the first mode starts.

Abstract: An illumination device, an LED driver circuit, a bleeder control circuit and a control method are provided. An AC input voltage is transmitted to a bus line after phase-cut processing. The bleeder control circuit includes a timing module configured to receive a bus voltage and at least one threshold voltage and generate a first time signal; a time processing module configured to receive the first time signal and generate a second time signal based on the first time signal in a previous power frequency half-wave cycle; and a control signal generation module configured to receive the second time signal and generate a first control signal for controlling a bleeder circuit. The beneficial effects of the present disclosure include the bleeder circuit being accurately controlled through the detection of the bus voltage and the implementation of the adaptive control method, thereby improving the operational efficiency and stability of the system.