82results about How to "Improve circuit stability" patented technology

An LED driver is provided for driving a plurality of light emitting diodes (LEDs), having a current controller to control a power supply of a predetermined power source unit to establish a current in the plurality of LEDs at a predetermined target current value and which sequentially changes corresponding to the respective LEDs, a plurality of divergence switches to allow flow or interrupt flow of the current with respect to each of the plurality of LEDs, and a divergence switch controller to sequentially open and close the plurality of divergence switches corresponding to changes of the target current value to make one of the plurality of divergence switches turn on before another one of the plurality of divergence switches is turned off. Thus, the LED driver has high light efficiency and excellent circuit stability without electromagnetic interference (EMI).

A voltage regulator is provided having high accuracy, low PSRR, and no headroom limitation. Generally, the regulator includes: an operational amplifier (OPAMP) having a non-inverting input coupled to a reference voltage; an output source follower coupled to and controlled by an output of the OPAMP, the output source follower including a drain coupled to a voltage source and a source coupled to an output-node of the regulator; a replica source follower coupled to and controlled by the OPAMP, the replica source follower including a drain coupled to the voltage source and a source coupled to circuit ground through a resistor network; and a feedback circuit extending from the output-node through a feedback resistor to the source of the replica source follower and through at least a first resistor of the resistor network to an inverting input of the OPAMP to couple a feedback voltage thereto. Other embodiments are also provided.

A voltage controlled oscillator with anti supply voltage variation and / or process variation includes an oscillation circuit for outputting an oscillatory signal; a current source coupled to the oscillation circuit for providing an input current to the oscillation circuit; and a variation compensation circuit for compensating the variations generated by the supply voltage and process. The variation compensation circuit includes a peak detector for generating a peak voltage proportional to the amplitude of the oscillatory signal; a compensating voltage generator for generating a reference voltage according to the process variation so that the oscillation circuit achieves the same working conditions under the process variation; and a comparator for comparing the peak voltage and the reference voltage to generate a control voltage. When the variation compensation circuit includes an amplifier, the supply voltage can be compensated.

A power converting device includes a transformer, a first switch coupled to a primary winding of the transformer, a PWM controller which generates a first PWM signal for controlling conduction and non-conduction of the first switch and which generates a control signal that leads the first PWM signal, a rectifier-filter circuit which rectifies an induced voltage generated by a secondary winding of the transformer, a second switch coupled to the secondary winding, and a synchronous rectifier controller which controls conduction and non-conduction of the second switch, and which controls, according to the control signal, the second switch to become non-conductive prior to conduction of the first switch.

A power converting device includes a main switch, a synchronous rectifier switch, a rectifier-filter circuit which outputs an output voltage, and a synchronous rectifier control circuit which includes a sampling circuit coupled to the rectifier-filter circuit for outputting a voltage variation signal, a differential amplifier circuit that outputs an amplified signal by adding the output voltage and an offset voltage to the voltage variation signal attenuated thereby, and a comparison circuit that compares the amplified signal with the output voltage so as to output a trigger signal, such that the synchronous rectifier switch is turned on when the main switch is turned off, and is turned off prior to conduction of the main switch.

A memory device, current sense amplifier and method of operating the same are disclosed herein. In accordance with one embodiment, the current sense amplifier circuit may include a pair of cross-coupled transistors, a pair of output nodes and a first pair of load transistors. The pair of cross-coupled transistors may be coupled for receiving a pair of differential currents and for generating a pair of differential voltages, which may then be supplied to the pair of output nodes. The first pair of load transistors may have mutually-connected gate terminals, mutually-connected drain terminals, and a source terminal coupled to a different one of the output nodes. In a unique aspect of the invention, an equalization transistor may coupled between the pair of output nodes for equalizing the pair of differential voltages for a predetermined amount of time at the beginning of a sense cycle. As such, the equalization transistor may be added to prevent the current sense amplifier circuit from generating erroneous results during the predetermined time period.

A pin definition layout of electronic paper display screen is provided. The electronic paper has a first pin area, a data signal source driver area, and a second pin area sequentially disposed at any side thereof. The first pin area and the second pin area each have a first power supply pin set and a second power supply pin set disposed thereon, and a plurality of No connections is disposed by intervals in the first power supply pin set and the second power supply pin set, so as to separate potential pins. Therefore, no interference is generated between the pins, thus achieving good electrical properties and reducing the wire complexity.

The invention discloses a GOA circuit for in-cell type touch display panel; during black screen, using a first global control signal to make a thirteenth N-type TFT conductive to raise a scan driving signal of each stage to high, using the first global control signal to make a twelfth N-type TFT conductive to pull down a voltage level of a second node, and pulling down a voltage level of a first node to avoid ineffective all-gate-on function; using a reset signal and a fourteenth N-type TFT to reset the second node to realize the normal output after awaking from black screen; during stop, setting a negative voltage as a pulse signal having same amplitude, phase and frequency as a touch signal, using a second global control signal to make the fifteenth N-type TFT conductive to output the negative voltage in pulse form to reduce cross-talk between the touch signal and a scan output end.

A scan driving circuit and a liquid crystal display device include a pull-up assembly, a pull-up control assembly that drives the pull-up assembly, a pull-down maintaining assembly, a reference low-level signal, and a down-transmitting assembly. A control end of the down-transmitting assembly is coupled to an output end of the pull-up control assembly and a control end of the pull-up assembly, and a current down-transmitting signal is output from an output end of the down-transmitting assembly.

An active device array substrate has a display area and a peripheral circuit area and further includes a plurality of pixel units, a plurality of signal lines, a plurality of testing pads and a first dielectric layer. The pixel units are arranged in the display area in an array. The signal lines and the testing pads are arranged in the peripheral circuit area. The first dielectric layer covers the testing pads. A testing method of the active device array substrate is that firstly removing a part of the first dielectric layer to expose a testing pad(s) desired to electrically contact with a testing tool. In other words, before the testing, the testing pads are electrically insulated from the exterior to prevent the pixel units from the electrostatic charges damage and thus the circuit stability of the active device array substrate can be improved.

An induction-heating cooking apparatus, operation of which is interrupted by container eccentricity is disclosed. Upon receiving an input signal varying with the degree of eccentricity of a container, the apparatus changes a reference signal for determining the presence or absence of a small load in proportion to a pulse-width control signal controlling the width of an inverter driving pulse. Although the eccentricity of the container occurs in a normal heating operation and completely escapes from a cook zone, the apparatus determines the occurrence of a no-load state, and interrupts an operation of an inverter circuit, resulting in increased stability of a circuit and a product.

An electronic static discharge (ESD) protection apparatus for a programmable device is provided. The apparatus can improve the turn-on efficiency and reduce the surface area of the chip efficiently by providing a low impedance current path which can sufficiently lower the voltage of the programmable device when ESD occurs. The ESD protection apparatus includes an ESD protection device, a programmable device, a first circuit, a second circuit, and a third circuit.

A current source apparatus for reducing interference with noise is provided. The current source apparatus includes a controllable current source and a feedback controller. The controllable current source provides an output current according to a control signal and produces a feedback signal according to the output of the controllable current source. The feedback controller is coupled to the controllable current source for receiving the feedback signal, and the feedback controller adjusts the control signal based on the feedback signal and outputs the control signal for controlling the controllable current source to output a stable output current.

The invention provides a GOA circuit for LTPS-TFT, using a resistor (R1) and a tenth TFT (T10) to replace the second capacitor in known technology, and change the diode-style connection of the ninth TFT (T9) in known technology to connect one end of the resistor (R1) to the constant high voltage (VGH) and the other to the gate of the ninth TFT (T9) so that during the output end (G(n)) staying at low, the voltage of the second node (P(n)) follows the (M+1)-th clock signal (CK(M+1)) to switch between high and low, that is, following a fixed frequency to pull down the voltage of the second node (P(n)), prevents the second node from staying at high for long duration and prevents the sixth TFT (T6) and the seventh TFT (T7) from prolonged operation to cause threshold voltage shift and improve GOA circuit stability.

A plasma display apparatus and a driving method thereof are disclosed. The plasma display apparatus comprises a plasma display panel in which a plurality of electrodes are formed, an energy storage unit for storing energy applied to the electrodes, and a protector for maintaining a voltage level of the energy stored in the energy storage unit at a predetermined voltage range.

The invention discloses an OLED pixel circuit and an image display device. The OLED pixel circuit comprises an OLED element, a driving transistor, a voltage maintaining circuit and a first reset circuit, The control end of the driving transistor is directly or indirectly connected with data voltage, the driving transistor is suitable for generating driving current according to the data voltage andoutputting the driving current through the output end of the driving transistor, and the driving current is used for driving the OLED element to emit light. The voltage maintaining circuit is suitable for maintaining the voltage of the control end of the driving transistor; And the first reset circuit is coupled with the control end of the driving transistor and is suitable for resetting the voltage of the control end of the driving transistor to a first reset voltage in response to a reset control voltage after the OLED pixel circuit updates the driving current by using the data voltage. Byadopting the technical scheme of the invention, the characteristic drift of the driving transistor in the OLED pixel circuit can be effectively prevented.

A bistable circuit includes an input terminal (41) for a set signal, an input terminal (42) for a reset signal, an output terminal (48) for a state signal, a thin-film transistor (M2) for increasing a potential of the output terminal (48) based on a first clock, a thin-film transistor (M1) for increasing a potential of a first-node connected to a gate terminal of the thin-film transistor (M2) based on the set signal, a thin-film transistor (M5) for decreasing the potential of the first-node, a thin-film transistor (M7) for increasing a potential of a second-node connected to a gate terminal of the thin-film transistor (M5) based on the reset signal, a thin-film transistor (M6) for decreasing the potential of the output terminal (48) based on the potential of the second-node, a thin-film transistor (M3) for increasing the potential of the second-node based on the set signal, and a capacitor (CAP2) having one end connected to the second-node and the other end connected to the input terminal (41).

An LED backlight drive circuit comprises a plurality of LED lamp strings connected in parallel, a constant-current control circuit for controlling magnitudes of currents flowing through the LED lamp strings to be the same, and a plurality of constant-voltage units. The number of the constant-voltage units is the same as that of the LED lamp strings. The constant-voltage units are connected between the LED lamp strings and the constant-current control circuit respectively. Each constant-voltage units comprises an MOS transistor and a first operational amplifier. The MOS transistor has a drain connected to a cathode of a corresponding LED lamp strings, a gate connected to an output terminal of the first operational amplifier and a source connected to the constant-current control circuit. The first operational amplifier has a positive input terminal connected to a reference voltage and an inverting input terminal connected to the source of the MOS transistor.

A power converting device includes a transformer, a first switch coupled to a primary winding of the transformer, a PWM controller which generates a first PWM signal for controlling conduction and non-conduction of the first switch and which generates a control signal that leads the first PWM signal, a rectifier-filter circuit which rectifies an induced voltage generated by a secondary winding of the transformer, a second switch coupled to the secondary winding, and a synchronous rectifier controller which controls conduction and non-conduction of the second switch, and which controls, according to the control signal, the second switch to become non-conductive prior to conduction of the first switch.

An induction-heating cooking apparatus, operation of which is interrupted by container eccentricity is disclosed. Upon receiving an input signal varying with the degree of eccentricity of a container, the apparatus changes a reference signal for determining the presence or absence of a small load in proportion to a pulse-width control signal controlling the width of an inverter driving pulse. Although the eccentricity of the container occurs in a normal heating operation and completely escapes from a cook zone, the apparatus determines the occurrence of a no-load state, and interrupts an operation of an inverter circuit, resulting in increased stability of a circuit and a product.

The present invention discloses a flexible LED light bar, which includes a flexible circuit board, a light cup, an LED chip, and an LED encapsulation material. The light cup is formed on the flexible circuit board. The LED chip is encapsulated in the light cup and is bonded to the flexible circuit board to form electrical connection therebetween. The present invention also provides a manufacturing method of a flexible LED light bar. The present invention simplifies the manufacturing process of the flexible LED light bar, reducing the manufacturing cost, and also improves product reliability

An LED driver is provided for driving a plurality of light emitting diodes (LEDs), having a current controller to control a power supply of a predetermined power source unit to establish a current in the plurality of LEDs at a predetermined target current value and which sequentially changes corresponding to the respective LEDs, a plurality of divergence switches to allow flow or interrupt flow of the current with respect to each of the plurality of LEDs, and a divergence switch controller to sequentially open and close the plurality of divergence switches corresponding to changes of the target current value to make one of the plurality of divergence switches turn on before another one of the plurality of divergence switches is turned off. Thus, the LED driver has high light efficiency and excellent circuit stability without electromagnetic interference (EMI).

The present invention discloses a method for adjusting a reference voltage, including: decoding a default code configured in a reference voltage register in a chip to obtain an actual reference voltage; comparing the actual reference voltage with a benchmark value to obtain a deviation value between the two; configuring an adjustment code according to the deviation value; and, burning the adjustment code into a nonvolatile storage medium. The present invention also discloses an apparatus for adjusting a reference voltage. According to the method and apparatus for adjusting a reference voltage provided by embodiments of the present invention, the reference voltage need not be adjusted according to an external power supply's different application schemes. Thus, adjustment on the reference voltage of the chip is standardized and costs of the chip's application schemes are saved. Embodiments of the present invention further provide a method and apparatus for obtaining a reference voltage, which makes it not necessary to configure a dedicated reference voltage pin in the chip for introducing an external reference voltage, and thus stability of the circuit's working is improved and costs of the chip's applications are decreased.

An active device array substrate has a display area and a peripheral circuit area and further includes a plurality of pixel units, a plurality of signal lines, a plurality of testing pads and a first dielectric layer. The pixel units are arranged in the display area in an array. The signal lines and the testing pads are arranged in the peripheral circuit area. The first dielectric layer covers the testing pads. A testing method of the active device array substrate is that firstly removing a part of the first dielectric layer to expose a testing pad(s) desired to electrically contact with a testing tool. In other words, before the testing, the testing pads are electrically insulated from the exterior to prevent the pixel units from the electrostatic charges damage and thus the circuit stability of the active device array substrate can be improved.

The invention provides a GOA circuit for LTPS-TFT, using a resistor (R1) and a tenth TFT (T10) to replace the second capacitor in known technology, and change the diode-style connection of the ninth TFT (T9) in known technology to connect one end of the resistor (R1) to the constant high voltage (VGH) and the other to the gate of the ninth TFT (T9) so that during the output end (G(n)) staying at low, the voltage of the second node (P(n)) follows the (M+1)-th clock signal (CK(M+1)) to switch between high and low, that is, following a fixed frequency to pull down the voltage of the second node (P(n)), prevents the second node from staying at high for long duration and prevents the sixth TFT (T6) and the seventh TFT (T7) from prolonged operation to cause threshold voltage shift and improve GOA circuit stability.

The present invention provides a camera module and a molding circuit board assembly, circuit board and application thereof, the circuit board comprising a digital circuit unit, an analog circuit unit and a substrate. The digital circuit nit and the analog circuit unit are respectively formed on the substrate, and the digital circuit unit and the analog circuit unit are conductively connected to each other, wherein at least one part of the analog circuit unit has a safe distance from the digital circuit unit, so as to prevent an electromagnetic wave generated by a circuit of the digital circuit unit from interfering with an electrical signal transmitted and processed by the analog circuit unit, thereby improving the stability and reliability of the transmission and the processing of the electrical signal by the circuit board.

The invention discloses a shift register, a gate drive circuit, a display panel and a control method. The shift register comprises an input sub-circuit, a pull-down node driving sub-circuit, an output sub-circuit, a noise reduction sub-circuit and a first reset sub-circuit, the pull-down node driving sub-circuit comprises a first access unit, a first voltage reduction unit and a second access unit, and the pull-down node driving sub-circuit is configured as follows: under the control of a first voltage signal end and a pull-up node, a first voltage signal provided by a first voltage signal end is transmitted to a first pull-down node through a first access unit, and the voltage applied to a second access unit is reduced through a first voltage reduction unit; and under the control of the pull-up node, a second voltage signal provided by the second voltage signal end is transmitted to the first pull-down node through the second access unit. According to the shift register provided by the invention, the voltage reduction unit is arranged to reduce the voltage on the second access unit, so that the stability of the shift register circuit is improved, and the stability of the GOA circuit is further improved.

It is an object to provide a DC / DC converter that can stabilize power supply potential in use. It is another object to provide a semiconductor device in which circuit operation is stabilized. In addition to a power supply that supplies potential to be reference potential of boosting in a DC / DC converter, a power supply for charging a capacitor in the DC / DC converter is provided. Accordingly, loads to the power supply that supplies the reference potential of boosting can be reduced. Further, as power for charging the capacitor in the DC / DC converter, power supplied from not an antenna but a secondary battery is used. More specifically, a secondary battery is used as a power supply that supplies power to a buffer circuit or an inverter circuit. Thus, power supplied from the antenna can be stabilized. In other words, operation of a logic circuit and an analog circuit can be stabilized.

A power converting device includes a main switch, a synchronous rectifier switch, a rectifier-filter circuit which outputs an output voltage, and a synchronous rectifier control circuit which includes a sampling circuit coupled to the rectifier-filter circuit for outputting a voltage variation signal, a differential amplifier circuit that outputs an amplified signal by adding the output voltage and an offset voltage to the voltage variation signal attenuated thereby, and a comparison circuit that compares the amplified signal with the output voltage so as to output a trigger signal, such that the synchronous rectifier switch is turned on when the main switch is turned off, and is turned off prior to conduction of the main switch.