Abstract: An ambient light filter configured to filter ambient light noises from an optical current that is at least partially caused by an optical pulse sequence emitted by a light emitting device, can include: a sample and detection circuit configured to sample the optical current and to obtain a current component in a first mode, and to remove the current component from the optical current and to generate a detection signal in a second mode; a current amplifier configured to receive the detection signal, and to generate an amplified current signal; and a control circuit configured to switch the sample and detection circuit between the first and second modes, where the control circuit switches the sample and detection circuit to the first mode in at least one optical pulse gap, and switches the sample and detection circuit to the second mode when a next optical pulse arrives.

Abstract: A control circuit for a switching regulator can include: an ON signal generator that generates an ON signal; an OFF signal generator that generates a first control signal according to an input voltage and an output voltage of the switching regulator; an on time regulator that generates an adjustment signal according to a switching signal and the first control signal; and a logic circuit configured to generate an off signal according to the first control signal, and to generate the switching signal according to the ON signal and the OFF signal, where the on time of the first switch is regulated according to the off time of the first switch when the off time of the first switch is less than the reference time, in order to regulate a duty cycle of the switching signal.

Abstract: The present disclosure relates to a power transmitter, a resonance-type contactless power supply and a control method. The inverter circuit is controlled to provide a high-frequency AC current with a voltage strength parameter so that a current strength parameter (e.g., a peak value or an effective value of the current) of the AC current flowing through a transmitting coil and that through a receiving coil have a predetermined relationship. Thus, an equivalent load impedance is adjusted so that the system efficiency is optimized.

Abstract: A charger power supply successively performs a constant-current charging process and constant-voltage charging process in accordance with a compensation signal. The process includes a plurality of first time periods during which a first output current is provided and a plurality of second time periods during which a second output current is provided. One of a current feedback loop and a voltage feedback loop is selected by comparing output signals of two loops. The current feedback loop has a first reference voltage compensated by a difference between a first voltage corresponding to a first output voltage during the plurality of first time periods and a second voltage corresponding to a second output voltage during the plurality of said time periods.

Abstract: There are provided an optical sensing assembly, a method for manufacturing an optical sensing assembly, and an optical sensing system. In the optical sensing assembly, a light emitting surface of a light emitting element is arranged in nonparallel to a light receiving surface of a light sensing element. Further, the optical sensing system is formed by the optical sensing assembly and a light guide assembly. Therefore, a distance between light emitted by the light emitting element to a to-be-detected object and light received by the light sensing element is increased, so that optical crosstalk can be greatly suppressed even if the optical sensing assembly has a small size, thereby improving distance detection accuracy.

Abstract: A laterally diffused metal oxide semiconductor structure can include: a base layer; a source region and a drain region located in the base layer; first dielectric layer located on a top surface of the base layer and adjacent to the source region; a voltage withstanding layer located on the top surface of the base layer and located between the first dielectric layer and the drain region; a first conductor at least partially located on the first dielectric layer; and a second conductor at least partially located on the voltage withstanding layer, where the first and second conductors are spatially isolated, and a juncture region of the first dielectric layer and the voltage withstanding layer is covered by one of the first and second conductors.

Abstract: A resonant switching converter can include: a voltage switching circuit configured to receive a first input voltage, and to generate a second input voltage of a resonant branch coupled to the voltage switching circuit; where when the voltage switching circuit is in a first operating state, the second input voltage provided to the resonant branch is less than the first input voltage; and where when the voltage switching circuit is in a second operating state, the input voltage provided to the resonant branch is zero.

Abstract: A method of controlling an isolated converter can include: (i) sampling and holding an output voltage of the isolated converter during a present switching cycle to generate a reference voltage signal that is proportional to the output voltage; (ii) comparing, in a predetermined time interval before a next switching cycle, the output voltage against the reference voltage signal, and activating a wake-up signal when the output voltage is less than the reference voltage signal, in order to control a voltage at a secondary winding to represent a variation of the output voltage; (iii) detecting a voltage of the primary winding or the secondary winding, and generating a voltage detection signal; and (iv) controlling the power switch according to the voltage detection signal, in order to maintain the output voltage as an expected voltage.

Abstract: A switching control circuit for controlling a multi-channel switching circuit having switching circuits, input terminals coupled to input voltage signals, and an output terminal for providing an output voltage signal, can include: a logic control circuit configured to receive an external operation signal and a first single pulse signal, and to generate an enable signal, a trigger signal, and feedback control signals; a reference voltage regulation circuit configured to receive the enable signal, the trigger signal, and a maximum one of the input voltage signals, and to generate a reference voltage signal; and feedback circuits corresponding to the switching circuits, where the plurality of feedback circuits are configured to receive the feedback control signals, a minimum one of two input voltage signals that are participating in the switching operation, the reference voltage signal, and the output voltage signal, and to generate switching control signals for controlling the switching circuits.

Abstract: A tire pressure monitoring device can include: a magnetic sensor configured to measure a first magnetic field intensity in a first direction, and to measure second magnetic field intensity in a second direction; and a controller configured to control a state of the tire pressure monitoring device based on a variation of the first magnetic field intensity and a variation of the second magnetic field intensity.

Abstract: A control circuit can include: a power supply circuit having a bias capacitor coupled between a power terminal and a common node, where the power supply circuit supplies power to the control circuit via the bias capacitor; a detection circuit coupled between the common node and a current output terminal of a main power switch of a power stage circuit, to detect current flowing through the main power switch; a current feedback circuit that generates a feedback signal according to a difference value between a sense value obtained from a voltage at the power terminal during an off state of the main power switch and a present voltage at the power terminal, where the feedback signal represents an inductor current of the power stage circuit; and a control signal generator that generates a control signal according to the feedback signal to control the main power switch.

Abstract: An LED drive circuit with a SCR dimmer, a circuit module and a control method therefor are provided. In each cycle of the alternating current, the bleeding current during a time period for turning on the SCR dimmer is distinguished from the bleeding current in a time period from an instant at which the SCR dimmer is turned on to an instant at which the LED load is lit. The bleeder circuit is controlled to perform bleeding at the first current during the time period for turning on the SCR dimmer, and then perform bleeding at the second current which is less than the first current from the instant at which the SCR dimmer is turned on, so that an average bleeding current of the bleeder circuit in each cycle can be reduced, the bleed loss can be reduced, and the efficiency of the LED drive circuit can be improved.

Abstract: Detecting an output voltage of a switching power supply can include: acquiring a first branch current that changes with a first voltage at a first terminal of an inductor of the switching power supply; acquiring a second branch current that changes with a second voltage at a second terminal of the inductor; controlling the first and second branch currents to flow to a same detection terminal; and detecting the output voltage based on a first current flowing through the detection terminal during a first time period, and a second current flowing through the detection terminal during a second time period.

Abstract: An LED drive circuit can include: a transistor and an LED load coupled in series, and being configured to receive a direct current bus voltage, and to generate an input current; and a control circuit configured to generate a drive signal to control an operation state of the transistor to control a distribution range of the input current by controlling an amount of accumulated charge of the input current during a half power frequency period.

Abstract: A power converter can include: first and second terminals; N A-type switching power stage circuits, each having a first energy storage element, where N is a positive integer, a first terminal of a first A-type switching power stage circuit in the N A-type switching power stage circuits is coupled to the first terminal of the power converter, and a second terminal of each of the N A-type switching power stage circuits is coupled to the second terminal of the power converter; one B-type switching power stage circuit; and N second energy storage elements, each being coupled to one of the N A-type switching power stage circuits, and the B-type switching power stage circuit is coupled between a terminal of one of the N second energy storage elements corresponding to the B-type switching power stage circuit and the second terminal of the power converter.

Abstract: An apparatus disposed below a housing, the apparatus including: a light-sensing element having a light-sensing region, and being configured to sense light reaching the light-sensing region through a first light-transmitting region of the housing; and where when the energy of the light that reaches the light-sensing region is reduced relative to the energy of the light that is expected to reach the light-sensing region, the area of the light-sensing region located under the first light-transmitting region increases.

Abstract: A tire pressure monitor can include: a pressure sensor configured to detect a gas pressure parameter of a tire; a wireless receiver configured to initially be in a sleep mode, and to receive a communication protocol wirelessly after being woken up from the sleep mode; and a microprocessor configured to wake up the wireless receiver according to the gas pressure parameter.

Abstract: A current source circuit and an LED driving circuit applying the same. A current at an output terminal of an operational transconductance amplifier is shunted based on a first control signal that includes duty cycle information, or an input signal at at least one input terminal of the operational transconductance amplifier is controlled to be switched between different voltage signals based on the first control signal, so as to adjust an output current of a current adjustment circuit. A driving voltage for driving a current generation circuit is adjusted based on the output current. Thereby, a driving current generated by the current source circuit is correlated with the duty cycle information. An amplitude modulation circuit used, a low-pass filter and the like for processing the first control signal are not used, effectively simplifying circuit design and improving system efficiency.

Abstract: A detection circuit configured to detect the presence of a TRIAC dimmer for an LED driver, can include: a sampling circuit configured to receive a DC bus voltage, and to generate a voltage sampling signal that characterizes the DC bus voltage; and a detector configured to determine whether the LED driver is provided with the TRIAC dimmer in accordance with a duration of the voltage sampling signal being continuously greater than a first reference voltage.

Abstract: Driving an LED load using a driving circuit includes controlling a power transistor coupled in series with the LED load to operate in a linear mode when an input voltage varying periodically is higher than a driving voltage for the LED load; adjusting a transistor current flowing through the power transistor based on a difference between the input voltage and the driving voltage, without calculating an error between an average current flowing through the LED load and a desired current; and where the transistor current is controlled to be decreased when the difference between the input voltage and the driving voltage is relatively large, in order to reduce a conduction loss of the power transistor, and to cause the average current flowing through the LED load to meet a predetermined requirement of driving the LED load.