45 results about "Voltage reference" patented technology

An LED lighting device of AC power-driven type having a comparatively simple constitution and a high power efficiency. The device compares a signal voltage (rectified voltage) obtained by rectifying an AC source with a predetermined reference voltage and controls ON/OFF of a driving current to each LED of an LED array in response to a comparison result. In this constitution, a large voltage of AC source enables lighting of more number of LEDs, while a small voltage thereof enables lighting of less number of LEDs, thus enhancing power efficiency of the LED lighting device.

A drive circuit is provided for an OLED pixel display. The drive circuit is adapted for use with a reference voltage source. It includes a first transistor and an OLED. The output circuit of the first transistor is operably connected between the reference voltage source and the OLED. Transmission gate means responsive to a control signal are provided to transmit a data signal to the first transistor. Means are provided for controlling the first transistor in accordance with a time domain modulation signal to provide an average current to the OLED which is a function of the data signal.

Light outputs from many LEDs are uniformized and power consumption required for such uniformizing is suppressed, in an LED lighting circuit to be used for illuminating apparatus and the like. Currents flowing from a DD converter to an LED module are detected by a current detection resistor and compared with a reference voltage (Vref) from a reference voltage source by a comparison circuit. Corresponding to the comparison results, a control circuit controls the DD converter, and the currents flowing to the LED module are controlled to be constant currents at the same time. Furthermore, in LED load circuits configuring the LED module, control elements configuring a current mirror circuit are arranged in series, a corresponding control element is permitted to have a diode structure by having a circuit with the highest sum of the LED ON voltages as a reference, the flowing current values of the control elements of the remaining circuits are interlocked, and the LED load circuits are balanced.

The bridgeless boost topology reduces the power dissipation, cost, and size of prior PFC systems by eliminating the intrinsic loss of the input rectifier bridge. Sensing of the input line voltage by the controller is unnecessary. The use of One Cycle Control (also known as Single Cycle Control) allows the Power Factor Correction function to be performed without complex rectification networks to obtain the AC line voltage reference. The use of bi-directional switches makes it possible to control inrush current (the startup over-current due to the charging of the output bulk capacitor), which allows elimination of over-current limiting devices and reduction of the diode surge capability requirements. Moving the boost inductor to the system input adds an additional filtering function, reducing the cost of input EMI filtering.

The present disclosure illustrates a feedforward controlled envelope modulator and a feedforward control circuit thereof. The feedforward controlled envelope modulator comprises a linear amplifier circuit, a switching amplifier, and a feedforward control circuit. The linear amplifier circuit amplifies an input voltage signal, so as to output an output voltage signal to a load node. The switching amplifier receives a comparison signal, and outputs a switching current to the load node according to the comparison signal. The feedforward control circuit comprises a duplicate linear amplifier circuit and a hysteresis comparator. The duplicate linear amplifier circuit amplifies the input voltage signal, so as to output a reference voltage signal, wherein an amplifying gain of the duplicate linear amplifier circuit is identical to an amplifying gain of the linear amplifier circuit. The hysteresis comparator compares the output voltage signal and the reference voltage signal, so as to output the comparison signal.

The invention relates to a smooth switching control method for an operating mode of a micro-grid inverter of different capacity micro sources. The method is applied to a micro-grid consisting of multiple different capacity micro sources. The method comprises the following steps: by virtue of switching among different switches, realizing smooth switching of an inverter control method under island/grid-connected operating modes, wherein the island operation is controlled by robust V-f based on capacitive equivalent output impedance so as to generate the voltage reference quantity, and the grid-connected operation is controlled by adopting PQ; adding a pre-synchronization link to be used for controlling the inverter output voltage to trace the power grid voltage when the inverter is switched from island operation to the grid-connected operation, and ensuring that the grid-connected operation is smoothly finished; introducing virtual impedance, designing the equivalent output impedance of the inverter to be capacitive, reducing loop current between parallel inverters, and well realizing power distribution among different capacity micro sources; and adopting double-loop control of the outer voltage loop and inner current loop, wherein the outer voltage loop is controlled by PI, and the inner current loop is controlled by dead beat. Therefore, the system is high in stability and high in dynamic response speed.

A reference voltage circuit includes first circuitry that generates a thermal voltage that is approximately proportional to absolute temperature, a first voltage multiplier, second circuitry that generates an inverse thermal voltage that is approximately inversely proportional to absolute temperature, a second voltage multiplier and a summer. The first voltage multiplier multiplies the thermal voltage to obtain a first multiplied voltage. The multiplied voltage is not equal to the thermal voltage. The second voltage multiplier multiplies the inverse thermal voltage to obtain a second multiplied voltage. The summer sums the first multiplied voltage with the second multiplied voltage to obtain a reference voltage.

An organic light emitting diode pixel driving circuit includes a pixel capacitor for storing a received voltage and coupling a change valve of the voltage at a first electrode thereof to a second electrode thereof; a first transistor for providing a reference voltage to the first electrode of the pixel capacitor under the control of a first light emitting signal; a third transistor for transmitting a data voltage to second electrode of the pixel capacitor under the control of the first scanning signal; and a fourth transistor; thereby overcoming the uneven display of the entire image, which is caused by the drift of the threshold voltage of the driving transistor and the different driving current driving the different OLEDs to emit light when the different OLEDs receive the same image data signal, the different driving current is caused by the difference the high-level power supply voltages.

Devices and methods for operating devices are provided, such as those that include a memory device having a reference voltage (Vref) circuit that has substantially similar paths and impedances as an on-die termination (ODT) circuit. One such Vref circuit tracks supply variations and temperature changes in a manner substantially similar to the ODT circuit. In some embodiments an update scheme is provide for the ODT circuit and the Vref circuit to enable simultaneous update of each circuit through the same digital codes.

A battery voltage measuring system includes an analog/digital converter configured to receive a higher reference voltage and a lower reference voltage which is lower than the higher reference voltage and to outputs a digital output value based on an input voltage which is lower than the high voltage reference voltage and is higher than the low voltage reference voltage. A battery supplies a battery voltage as the higher reference voltage to the analog/digital converter; a first power supply supplies a first reference voltage as the input voltage to the analog/digital converter; and a second power supply supplies a second reference voltage as the lower reference voltage to the analog/digital converter.

A TTL and CMOS compatible type input buffer comprises a reference voltage generator and an input buffer which comprises at least one stage input invertor which include a PMOS tube P1 and an NMOS tube N2, the grids of which are connected as an input end for inputting signal Vin, a source pole of the PMOS tube P1 is connected with a reference voltage VREF provided by the reference voltage generator; when the circuit works in the TTL mode, the reference voltage generator provides reference voltage VREF for the input invertor between 3.3 and 3.5 V, the turning point voltage of the input invertor is 1.4 V to make input noise margin maximum; when the circuit works in the CMOS mode, the reference voltage generator has no quiescent power dissipation, the reference voltage generator provides reference voltage VREF for the input invertor between 4.6 and 5 V, the turning point voltage of the input invertor is 2.5 V to obtain the maximum noise margin.

A square-law clamping circuit (99, 120) sinks a current from an input/output terminal proportional to a square of a difference between a voltage thereon and a reference voltage. A first MOS transistor (130) has a source for receiving the reference voltage, a gate, and a drain coupled to its gate. A current source (134) coupled to the drain of the first MOS transistor (130) sources a predetermined current therefrom. A second MOS transistor (132) has a source providing the input/output terminal (100, 121), a gate coupled to the drain of the first MOS transistor (130), and a drain. A current sink (135) coupled to the drain of the second MOS transistor (132) sinks a current therefrom.

A detecting device for a fuel injector includes a sensor unit and an ECU. The sensor unit is provided with a fuel pressure detection circuit which outputs a pressure detection signal in response to a fuel pressure. The ECU computes the fuel pressure based on a voltage value of the pressure detection signal relative to a reference voltage. The ECU obtains a comparative voltage according to an applied-voltage to the fuel pressure detection circuit and computes a deviation between the comparative voltage and the reference voltage. The sensor unit adjusts the applied-voltage in such a manner as to decrease the deviation. Thus, the computation accuracy of the fuel pressure is improved.

The invention provides an automatic calibration device for a multi-parameter physiological signal simulator. The automatic calibration device is designed in order to solve the technical problems that when measurement calibration is performed on an electrocardiosignal simulator or a multi-parameter physiological signal simulator at present, as a makeshift way is adopted, the signal is not stabilized, amplification factors cannot be adjusted, efficiency and precision are low, performance is unstable, and tracing is not available. According to the automatic calibration device, a signal input interface is directly connected with the calibrated simulator, and measurement calibration is performed on the calibrated simulator through a calibration output interface; tracing can be performed on time and voltage reference, multiple parameters such as the frequency and voltage of the calibrated simulator are traced to national measurement standards, and a communication interface is connected with an upper computer so that calibration data can be directly converted into a calibration record and saved. The automatic calibration device has the advantages that the structure of the device is compact, the calibration process is simple, and various auxiliary devices such as an oscilloscope and a counter do not need to be used; the device is of a high integration degree, high accuracy, high measurement precision, full-automatic operation and the like; in this way, the overall measurement calibration and tracing on the multi-parameter physiological signal simulator are completely achieved.

An output level stabilization circuit being an output level stabilization circuit for a CML circuit, the output level stabilization circuit includes: a replica circuit constituted of transistors respectively having the same characteristics as one of differential-pair transistors of the CML circuit and a current source transistor; a comparison circuit which compares an output of the replica circuit with a reference voltage and supplies the comparison result as a control voltage for the current source transistor of the replica circuit; and a variable impedance circuit arranged between the output of the replica circuit and an input of the comparison circuit.

A circuit that detects the power supply voltage requirement of each voltage domain in an IC includes 1) a ring oscillator in each voltage domain, and 2) a power module. Two different circuit implementations of the power module may provide a precise reference voltage to on-chip voltage regulators (LDO or DC-DC switching buck converter). The power module supports DVFS and can provide the desired power supply voltage for advanced CMOS technology nodes (45 nm and beyond) in less than 100 ns. The voltage detection circuit clamps the voltage to the desired level to address power supply voltage variations due to PVT and ageing. The proposed technique has minimal power and area overhead to compensate for the power supply voltage variation, thus reducing power supply voltage margins which yields higher power saving.

A reference voltage generator for improving setup voltage characteristics without an increase in a standby current and a method of controlling the same, in which the reference voltage generator includes: a reference voltage generation unit including a resistor connected between a power supply voltage and an output node, for dividing the power voltage, and generating a reference voltage fed to the output node thereof; a voltage detector receiving a feedback of the reference voltage and detecting a level of the reference voltage; and a bypass circuit connected in parallel to the resistor of the reference voltage generation unit and bypassing the resistor in response to an output signal of the voltage detector.

A method of driving a LED chip includes the following steps: generate a reference voltage, and accordingly control a driving unit to output electrical energy at a power corresponding to the strength of the reference voltage; obtain an operating current required by the LED chip; control the driving unit to output the operating current to the LED chip under the power corresponding to the reference voltage. Whereby, with different strengths of the reference voltage, the driving unit is capable of outputting electrical energy to the LED chip at different powers. Therefore, one single driving apparatus applied with the method is sufficient to replace multiple conventional driving apparatuses for LED chips.

The invention relates to a current comparison circuit, a memory and a current comparison method. The current comparison circuit comprises a first charging and discharging circuit, a first comparator, a second charging and discharging circuit, a second comparator and an edge detecting circuit, wherein the first charging and discharging circuit is suitable for charging a first charging and discharging node under the control of a control signal, or discharging the first charging and discharging node, and the current during the discharging is first current; the first input end of the first comparator receives reference voltage; the second input end of the first comparator is coupled with the first charging and discharging node, and outputs a first comparison result; the second charging and discharging circuit is suitable for charging a second charging and discharging node under the control of the control signal, or discharging the second charging and discharging node, and the current during the discharging is second current; the first input end of the second comparator receives reference voltage; the second input end of the second comparator is coupled with the second charging and discharging node, and outputs a second comparison result; the edge detection circuit is suitable for detecting the turning edges of the first comparison result and the second comparison, and a first and second current comparison result is obtained according to the time difference of the first comparison result and the second comparison result. The scheme has the advantage that the influence of the current comparison circuit on tested current can be avoided.

The invention discloses a modulation and voltage stabilization control method suitable for a single-power binary hybrid cascaded H-bridge multilevel inverter. In modulation, a modulated wave vm obtained through taking an absolute value of a sinusoidal modulated wave vref is compared with triangular carriers vca, vcb', vcr1' and vcr2' and a voltage constant value 2E to obtain five logic pulse signals A, B, R1, R2 and P; the sinusoidal modulated wave vref is compared with zero voltage to obtain a polar pulse signal D; and an optimized PWM drive signal is generated from the logic pulse signals and the polar pulse signal through a drive logic operational circuit. In voltage stabilization control, real-time adjustment is carried out on amplitudes of triangular carriers vcb, vcr1 and vcr2 through a signal obtained through operation of DC side voltage sampling signals Vdc1 and Vdc2 and voltage reference signals Vdc1* and Vdc2* of auxiliary units, thereby achieving voltage stabilization control on the auxiliary units through combining modulation. According to the control method disclosed by the invention, the stability of capacitor voltage can be controlled, output levels and the equivalent switching frequency of output voltage of the inverter can be improved and the output characteristics of a system are improved.

The invention relates to the field of particle imaging and relates to a particle imaging method and a particle imaging device. The particle imaging device mainly comprises a cluster source, a vacuum chamber, a flow divider, an ionic lens I, a gate valve I, an ionic lens II, a gate valve II, a mass filter, a microchannel disk I, a shielding cover, a voltage reference tube, a velocity imaging electrode set, a microchannel disk II, a detector, a laser I and a vacuum pump set, wherein the cluster source comprises a liquid storage tank, a flow controller, a sample feeding tube, an air pipe, an airstorage tank, a protection cavity, a condensing cavity, a heater, a sample cavity, a nozzle and a laser II. An air accumulation and laser evaporation combined method is utilized to generate doped macromolecule clusters, so that the sizes of the clusters are evener; furthermore, the doped measurement in the clusters is accurate and controllable, and the generated clusters can be quickly cooled; a method of switching voltage on an electrode is utilized to effectively gather the clusters, so that the light reaction strength is improved, and the light reaction efficiency is improved.

The invention discloses a main/standby power conversion detection circuit capable of switching off a power supply IC for a power supply module. The main/standby power conversion detection circuit comprises an input voltage module, a reference voltage module, a comparator, an optocoupler module and a power supply IC control module, wherein the input voltage module is connected with the AC input endof the power supply module and is used for filtering and dividing the voltage of the AC input end, the comparator compares the output voltage of the input voltage module with the output voltage of the reference voltage module, the optocoupler module is disconnected when the output voltage of the input voltage module is too low, and the power supply IC is controlled to be disconnected through thepower supply IC control module. The main/standby power conversion detection circuit can continuously detect the input voltage of the AC input end, automatically turn off the power supply IC when the input voltage is under-voltage, and turn on the power supply IC when the input voltage is normal, thereby realizing the under-voltage protection of the power supply IC, and avoiding the problems of heating and even burnout caused by the long-term operation of the power supply IC under the condition of low voltage.