176results about How to "Short on-time" patented technology

The invention provides a system for compensating the maximum output power of a switching power supply, which comprises an oscillator, a pulse width modulation generator, an over-current protector, a driver and a leading edge blanking device, wherein the pulse width modulation generator generates a pulse width modulation signal according to a current sampling signal and a power feedback signal which are output by a power switching tube, a periodic clock signal output by the oscillator and an over-current protecting signal output by the over-current protector; the over-current protector outputsthe over-current protecting signal to the pulse width modulation generator according to the pulse width modulation signal and the current sampling signal; and the driver receives the pulse width modulation signal and outputs a power control signal; and the over-current protector comprises a processing module and an over-current protecting signal generation module. The invention also provides a method for compensating the maximum output power of the switching power supply; by the invention, the effective starting power of the switching power supply can not be changed, thus overcoming the defects that an OPP recovery clearance of the system in the prior art is increased and the starting of the system is unsuccessful when being at low pressure.

The invention provides a shifting register unit, a shifting register, a gate drive circuit and a display device. The shifting register unit comprises an input module, an output module, a reset module and a pull-down module. The output module is used for outputting first clock signals of a first clock signal end to the output end of the shifting register unit according to the electric potential of pull-up nodes at the output stage. The reset module is used for lowering the electric potential of the pull-up nodes and the output end of the shifting register unit according to reset signals of pull-up nodes at the reset stage. The pull-down module is used for lowering the electric potential of the pull-up nodes and the output end of the shifting register unit according to second clock signals of a second clock signal end at the pull-down stage. The first clock signal end supplies the high-level first clock signals to the output module only at the output stage. The second clock signal end supplies the high-level second clock signals to the pull-down module only at the reset stage or the pull-down stage. Compared with the prior art, the shifting register unit has a simpler structure.

The invention belongs to the technical field of integrated circuit design, in particular to an adaptive turnon time control circuit for a high-frequency step-down voltage converter. The step-down voltage converter circuit consists of a power level circuit and a control level circuit, wherein the power level circuit consists of a power tube PMOS (P-channel metal oxide semiconductor), an NMOS (N-channel metal oxide semiconductor), a filtering inductor and a capacitor; and the control level circuit consists of a comparator, a control logic and an adaptive turnon time control circuit module. The adaptive turnon time control circuit consists of a frequency / phase discriminator, a charge pump-based low-pass filter and a voltage control delay unit, and is used for generating the turnon time of each cycle of the converter; and the adaptive turnon time control circuit and the control logic form a negative feedback loop for a DUTY signal so as to lock the switch frequency. In the invention, the turnon time control is superior to the traditional current or voltage mode control; and the adaptive turnon time control circuit is rapid in response and simple in structure, and can be applied to the power management chips of various portable electronic devices.

A PWM controller that effectively transitions between normal mode and green power mode is disclosed. A driver provides a normal drive signal during normal operation. A pulse width detector detects the pulse width of the PWM signal and if the pulse width drops below a threshold the normal mode drive signal will be turned off and a pulse ON time measurer will begin storing the pulse ON time. When the total ON time reaches a total ON time threshold or the output voltage drops below a voltage limit, a green mode drive signal will be output to the power converter. During green mode the driver will continue sending the green mode drive signal at intervals until a heavy load condition when the green mode drive signal will be shut off and the driver will resume sending the normal mode drive signal.

The invention provides a high-voltage side gate drive circuit capable of resisting noise interference. The high-voltage side gate drive circuit comprises a high-voltage level shift circuit, a differential-mode noise elimination circuit, an RS trigger and an output drive level circuit, wherein a low-side pulse signal is converted into a high-voltage pulse signal for output through the high-voltage level shift circuit; a common mode noise elimination circuit is connected between the output of the high-voltage level shift circuit and the input of the differential-mode noise elimination circuit; the common mode noise elimination circuit is used for eliminating a common mode noise signal generated in application; and the differential-mode noise elimination circuit eliminates the differential-mode noise introduced by process variations, outputs a normal pulse signal, reduces the normal pulse signal into a normal square signal through the RS trigger, outputs the square signal from the output drive level circuit and drives an external high-side power tube.

The invention relates to a composite contactor which belongs to the field of electric switches, in particular to a contactor suitable for powering on and off a power capacitor. In the invention, an input power supply is subjected to current limit by a capacitor voltage drop circuit and rectification by a rectifying circuit and used for supplying power to a control coil of the contactor; the capacitor voltage drop circuit is connected with a starting electronic switch in parallel, the control end of the starting electronic switch is connected to a control circuit, and the control circuit is connected with a working power supply; a voltage zero passage detection circuit and a controllable silicon circuit are connected to two ends of a mechanical contact of the contactor in parallel; and the output end of the voltage zero passage detection circuit and one on control end of the controllable silicon circuit are connected to the control circuit, while the other on control end of the controllable silicon circuit is connected to a contact bridge of the contactor. The control coil of the composite contactor adopts a capacitor voltage drop direct current working manner, and the controllable silicon circuit adopts a design with multiple control ends, so that the composite contactor has the advantages of environmental protection, energy saving, strong anti-jamming, power on work, power on with voltage zero passage, power off with current zero passage, short controllable silicon on time, high reliability and long operation service life.

The invention discloses a bootstrap power-supply MOSFET / IGBT driving circuit with a high negative voltage. The driving circuit comprises a superior power tube M1 driving circuit and an inferior power tube M2 driving circuit, wherein the superior power tube M1 driving circuit comprises a bootstrap power-supply circuit, a superior push-pull driving circuit, a superior negative voltage generation circuit and a superior protection circuit; and the inferior power tube M2 driving circuit comprises a low-voltage direct current stabilized power supply, an inferior push-pull driving circuit, an inferior negative voltage generation circuit and an inferior protection circuit. The driving circuit has the benefits as follows: the problem that negative voltage turn-off is difficult to realize on a traditional bootstrap power-supply basis is solved, and the problems that traditional negative voltages are not stable enough and the negative voltages are reduced along with the increase of power are solved; and both the conciseness of the circuit and the reliable turn-off of power tubes can be guaranteed.

The invention discloses a DC electronic arc-extinguishing device which belongs to the field of electricity, particularly a DC electronic arc-extinguishing device suitable for extinguishing arc for a mechanical switch. The DC electronic arc-extinguishing device comprises a power semiconductor device which is parallelly connected with both ends of the mechanical switch in need of arc extinguishing, and is characterized in that a control end of the power semiconductor device is connected with a control circuit, a main loop of the power semiconductor device is connected with the control circuit through a capacitor or a resistor, voltage variations at both ends of the main loop of the power semiconductor device are connected to the control circuit through a capacitor or a resistor, and the control circuit generates a pulse control signal to control the power semiconductor device to be switched on. The DC electronic arc-extinguishing device has the advantages of extremely short switching-on time required by the power semiconductor device, low cost and high reliability.

The invention discloses a switching power supply, a circuit and a method for controlling constant on-time. When the switching frequency of a switching circuit approximates to an audio frequency range, the switching power supply enters a sleep mode, and on-time of a switching tube is shortened to increase the switching frequency of the switching circuit, so that audio noise is avoided.

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 secondary type high-gain boosting converter with switched capacitors and a coupled inductor. The secondary type high-gain boosting converter comprises a direct-current input power source, a first inductor, a first diode, the coupled inductor, the first capacitor, a second diode, a switching tube, a third diode, the second capacitor, a fourth diode, the third capacitor, a fifth diode, the fourth capacitor, a sixth diode, the fifth capacitor, a seventh diode, an eighth diode, the first output capacitor, the second output capacitor and a load. According to the secondary type high-gain boosting converter, a driving circuit and a main circuit are grounded together and share only one switching tube, a control circuit is simple, the higher output voltage gain is obtained under the low duty ratio, the input current and output voltage ripples are reduced, the voltage stress and turn-on losses of a switching element are reduced, meanwhile, the turn ratio of the coupled inductor needed by the circuit is small, and the saturation problem of a magnetic core component is avoided. The secondary type high-gain boosting converter is quite suitable for occasions of low-voltage input and high-voltage output.

The invention provides a control and drive circuit applied to a synchronous rectification switching mode power supply. The circuit comprises a primary switching tube controller, a logic circuit, a switching circuit and a synchronous rectifier tube controller, wherein the primary switching tube controller is used for generating a primary switching tube control signal, the logic circuit is used for generating a first control signal according to received primary switching tube control signal, the switching circuit is used for generating a second control signal according to the received first control signal, and the synchronous rectifier tube controller is used for generating a synchronous rectifier tube control signal according to the received second control signal and guaranteeing phases of the primary switching tube control signal and the synchronous rectifier tube control signal to be the same or inverse according to a topological structure of the synchronous rectification switching mode power supply. The invention further provides a control and drive method, so that the synchronous rectifier tube control signal for controlling on and off of a synchronous rectifier tube is generated according to the primary switching tube control signal, the problem of cross connection of the synchronous rectification power supply is solved, and high frequency, low cost, small size and high efficiency of the synchronous rectification switching mode power supply are achieved.

The invention belongs to the field of electronics, and particularly discloses a current monitoring type electronic arc-control device which is suitable for the arc-control purpose for a mechanical switch. The current monitoring type electronic arc-control device comprises a power semiconductor device connected with the mechanical switch. At least one current sensor is connected with the mechanical switch and used for detecting the switch-on and switch-off of the mechanical switch. The output end of the current sensor and the control end of the power semiconductor device are connected with a control circuit. The control circuit controls the power semiconductor device to be powered off when detecting the switch-off of the mechanical switch. The current monitoring type electronic arc-control device has the advantages that the switch-on time of a thyristor is short, and reliability is high.

The invention discloses a constant voltage output switching power supply with a high power factor, which is composed of a rectifying and filtering circuit, a power converter, a control circuit, an output voltage feedback circuit, an inductive current zero-crossing feedback circuit and a chip power supply circuit. The constant voltage output switching power supply is characterized in that alternating current is inputted and converted into direct current through the rectifying and filtering circuit, the direct current is inputted into the power converter, the direct current is outputted to a load circuit from the power converter, then detection is carried out on a main power circuit through the output voltage feedback circuit, the inductive current zero-crossing feedback circuit and the chip power supply circuit, an acquired result is inputted into the control circuit so as to enable the control circuit to operate and obtain a control scheme, and output of the control circuit is transmitted to the power converter so as to perform control on the power converter. According to the constant voltage output power supply system with a high power factor, the turn-on time of a power switch tube is controlled to be constant through design of the control circuit and the feedback circuit; constant voltage output can be achieved in a full voltage range, and a high power factor can be ensured.

The invention discloses a switch converter comprising a main transistor, and a controller and control method of the switch converter. The controller comprises a clock generation circuit and a control circuit. The clock generation circuit generates a clock signal deciding the switch frequency of the main transistor. The control circuit is coupled to the clock generation circuit and generates a control signal according to the clock signal and a feedback signal representing the output signal of the switch converter to control the main transistor. The clock generation circuit is further coupled to the control circuit to receive the control signal and judges whether the on time of the main transistor is smaller than a time threshold value according to the control signal. If the on time of the main transistor is smaller than the time threshold value, the clock generation circuit changes the frequency of the clock signal to adjust the on time of the main transistor to be equal to the time threshold value.

The method includes following steps: a) in paging process the called VLR receives request for providing roaming number for called HLR; b) the called VLR sends out pre-paging through MSC in call area where the called party is at and decides if it is succeeded, if yes, then entering into step d, otherwise entering into step c; c) it is decided if the called subscriber enables the follow-on-call in the end office according to cause of failure, if yes, then entering into step d, otherwise entering into step e; d) the called VLR returns successful response to called HLR and continues normal process, then ending; e) the called VLR returns failure response to the called HLR and makes process according to cause of failure, then ending.

The invention provides a multi-pole ignition device of an impulse voltage generator. The invention is characterized in that the device mainly comprises a pulse voltage generator, a multi-pole main clearance and a transmission resistance capacitor; the pulse voltage generator consists of a low voltage primary winding W1 and two high voltage secondary windings W2 and W3; the multi-pole main clearance consists of a plurality of small clearances 1; each small clearance 1 is provided with two tungsten-copper alloy rods 13; the transmission resistance capacitor consists of a transmission capacitor 4 and a transmission resistance 5. Owning to short conduction time of the multi-pole main clearance, the ignition process and the ignition pulse transmission process of each pole are achieved at the same time; the impulse voltage generator has good synchronousness, is not required to adjust the sphere gap before the impulse voltage is generated each time and is not affected by the environmental condition, has wide range of triggered voltage and small dispersion, and leads to easy breakdown of the clearance of each pole.

The invention belongs to the field of electronic technology, and relates to an inductively coupled power transfer (ICPT) device with a pull-down auxiliary switch. A group of pull-down auxiliary switch branch is added to an LC resonant single tube inverting bipolar inverting circuit topology used by the existing ICPT device, the branch comprises an auxiliary switch tube, a main switch tube and the auxiliary switch tube have the same switch frequency, soft switch control can be both realized, no shoot-through problem exists between the two tubes, and the reliability is improved. In a condition of keeping the advantages of the original circuit, voltage borne at two ends of the switch tube is reduced to 2 / 3 the original voltage, the device can adopt a metal oxide transistor as a switch tube, the switch frequency can reach more than 83kHz, and as the auxiliary switch tube is short in turn-on time and low in power consumption, a technical scheme for furthering reducing the size and the weight of the ICPT device and reducing the cost is provided.

The invention relates to a static discharging circuit, which comprises a voltage division circuit, a first N-channel metal oxide semiconductor (NMOS) tube and a second NMOS tube, wherein a positive electrode input end of the voltage division circuit is connected with a high-voltage input end, a negative electrode input end of the voltage division circuit is coupled with the ground, and an output end is connected with a grid electrode of the first NMOS tube and is used for outputting bias voltage conducting the first NMOS tube; a drain electrode of the first NMOS tube is connected with the high-voltage input end, and a source electrode is connected with a drain electrode of the second NMOS tube; and a source electrode of the second NMOS tube is grounded, and a grid electrode of the second NMOS tube is coupled with the ground. The static discharging circuit has the advantages that the circuit voltage resistant value is improved, and meanwhile, the static discharging performance of the static discharging circuit is also improved.

The present disclosure discloses a backlight control circuit for adjusting a current of an LED module of an electronic device including a driving chip having a feedback terminal and a reference voltage terminal, a feedback voltage regulating unit, and a power supply regulating unit; the feedback voltage regulating unit is also connected to the 2D / 3D signal terminal, the feedback terminal voltage is controlled so that the feedback terminal voltage of the feedback terminal of the driving chip is lower than the reference voltage of the reference voltage terminal when receiving the three-dimensional signal generated at the 2D / 3D signal terminal. The present application also provides an electronic device. With the scheme of the present application, the current of the LED module can be increased when the electronic device is in the three-dimensional mode.

The invention relates to a digital controllable annular voltage-controlled oscillator circuit. The current product has low quality factor and poor phase noise. The circuit comprises a multistage delay unit, and each stage includes four NMOS (N-channel Metal Oxide Semiconductor) tubes, four PMOS (P-channel Metal Oxide Semiconductor) tubes and a switch capacitor array; a plurality of switch units are connected in parallel to form a switch capacitor array, and the switch capacitor is a three-dimensional interdigital capacitor; the first same-phase input end of the middle stage delay unit is connected with the reverse phase output end of the previous stage and the second same-phase input end of the next stage, the first reverse phase input end of the middle stage delay unit is connected with the same-phase output end of the previous stage and the second reverse phase input end of the next stage, the second same-phase input end of the middle stage delay unit is connected with the first same-phase input end of the previous stage, the second reverse phase input end of the middle stage delay unit is connected with the first reverse phase input end of the previous stage, the reverse phase output end of the middle stage delay unit is connected with the first same-phase input end of the next stage, the same-phase output end of the middle stage delay unit is connected with the first reverse phase input end of the next stage, and the first stage delay unit is reversely connected with the last stage delay unit. The digital controllable annular voltage-controlled oscillator circuit increases the oscillating frequency, reduces the phase noise and has the advantages of high capacitor density and compatibility with digital technology.

A PWM controller that effectively transitions between normal mode and green power mode is disclosed. A driver provides a normal drive signal during normal operation. A pulse width detector detects the pulse width of the PWM signal and if the pulse width drops below a threshold the normal mode drive signal will be turned off and a pulse ON time measurer will begin storing the pulse ON time. When the total ON time reaches a total ON time threshold or the output voltage drops below a voltage limit, a green mode drive signal will be output to the power converter. During green mode the driver will continue sending the green mode drive signal at intervals until a heavy load condition when the green mode drive signal will be shut off and the driver will resume sending the normal mode drive signal.

The invention relates to a Z-source high-gain low-switching-stress direct current boost converter. On the basis of a traditional boost direct-current converter topological structure, a novel circuit topological structure is achieved by adopting a mode that an X-type Z-source network, a simple inductor and a simple capacitor are connected in series and parallel. The Z-source high-gain low-switching-stress direct current boost converter can obtain high voltage conversion gain and further reduce voltage stresses exerted onto two ends of a master switch, and a development target of enabling the direct current boost converter to be efficient, small in size and low in noise and cost is effectively achieved. Under the condition of low duty ratio, high gain is achieved. Due to the fact that the breakover time of the master switch is shortened, a peak value of input current is effectively reduced, and breakover consumption is reduced. The voltage stress of a switch tube is reduced from (i)Vo( / i) to (i)Vo( / i) / 3, 2(i)Vo( / i) / 3, and the hardware manufacturing cost is reduced. A transformer, a coupling inductor and a multistage connecting mode are not needed, and a circuit topological structure is simple. The target of enabling the direct current boost converter to be efficient, small in size and low in noise and cost can be achieved.

A single-ended circuit, such as an LNA (300), in accordance with the present invention includes an input power matching circuit (310) and a bias circuit (305) connected to an output transistor (Qin) which provides the amplification. A degeneration inductance (Le) and load impedance (Lo) couple to the emitter and collector of the output transistor (Qin), respectively. The bias circuit (305) is configured to eliminate base shot-noise of the mirror transistor (Q1) which generates the amplification. The bias circuit (305) in accordance with the present invention also eliminates the noise of the bias resistor (Rx1) that is included within the bias circuit (305). Specifically, the bias circuit (305) includes a current reference source (Iref) and an emitter follower circuit (315) connected to a current mirror circuit (Q1, Q2, Rx2) that connects to a bias resistor(Rx1). This bias circuit (305) can be implemented in a wide-class of single-ended circuits.

This invention relates to a switching power converter, and an controlling method used for a first synchronous rectifier and a second synchronous rectifier, the switching power converter comprises a transformer, a first on-off device and a second on-off device, the first one is serially connected with the second one and both are connected in parallel to a input voltage source, the first synchronous rectifier is linked to a low-pressure of a secondary side winding of the transformer, the second synchronous rectifier is linked to a high-pressure of the secondary side winding, the first on-off device is linked to a high-pressure of input voltage source, and the second on-off device is linked to a low-pressure. The controlling method comprises the following steps: driving the first on-off device to be on state and the second device to be off state; when the second on-off device is driven to be in on state, driving the second synchronous rectifier to be off state, making the power source convey from primary side winding to the secondary side winding.

The invention discloses an integrative control method of ultrared human body induction and a switch. The method comprises the following steps: A. a human body enters an induction area along a direction, and a precontrol state is established, wherein the induction area is opened when the human body comes and closed when the human body leaves; B. the following situations sequentially occur; C. whenthe human body enters the second part of the induction area from the induction area, the switch enters the precontrol state; D. when the human body enters the third part of the induction area from theinduction area, the switch is in a switch-on state; and E. when the human body enters the fourth part of the induction area from the induction area, the switch enters the precontrol state. A high-efficiency power module, an ultrared pyroelectric sensor unit, a logic unit and an electronic switching device are sequentially connected, wherein the input end of the high-efficiency power module is connected with a power source; and the output end of the high-efficiency power module is sequentially connected with the power source input end of the ultrared pyroelectric sensor unit, the power sourceinput end of the logic unit and the power source input end of the electronic switching device. The invention has remarkable energy-saving effect, wide control range, high induction sensitivity, ultra-long service life, simple and convenient mounting and maintenance and reliable work.

The invention discloses an inrush flow-free switching device and a control method thereof, and belongs to the electric field, and discloses the inrush flow-free switching device especially suitable for switching of capacitors and other capacitive loads, and the control method thereof. The inrush flow-free switching device comprises a mechanical switch, a first unidirectional thyristor, a second unidirectional thyristor, a control unit, and a limiting element. The first unidirectional thyristor is serially connected with the limiting element to form a serial connection circuit. The serial connection circuit is parallely connected with the second unidirectional thyristor, and the two ends of the main circuit of the mechanical switch are parallely connected with the second unidirectional thyristor. The control unit is connected with the control end of the mechanical switch, and is connected with the first unidirectional thyristor and the second unidirectional thyristor. The motion time parameters of the mechanical switch are pre-stored in the control unit. The inrush flow-free switching device has advantages of short conduction time of thyristors, strong overload capability, high cost performance, long electric service lifetime of mechanical switch, and high reliability.

The invention relates to a BUCK converter bootstrap driving circuit based on narrow pulse control, which at least comprises a BUCK circuit, a bootstrap charging branch and a driving chip for driving the bootstrap charging branch are connected in the BUCK circuit, and when the BUCK circuit is in a light-load / no-load state and the duty ratio of a main switching tube of the BUCK circuit is less thana first threshold, the driving chip reduces the conduction time of an auxiliary switch tube in the bootstrap charging branch circuit based on a narrow pulse driving mode so as to prevent the BUCK circuit and the bootstrap charging branch circuit from generating negative current or reduce the negative current in the BUCK circuit and the bootstrap charging branch circuit.