73 results about "Voltage controlled resistor" patented technology

The invention discloses a pixel circuit for a silicon-based AMOLED driving chip, which comprises a driving tube MN2, a switching tube MP2, a voltage controlled resistor and a storage capacitor C2. Resistance of the voltage controlled resistor is increased along with decreasing of pixel data voltage Vdata, OLED anode voltage in a dark state is reduced, pixel output current becomes small, and thus the minimal brightness is lower; resistance of the voltage controlled resistor is decreased to be ignored along with increasing of pixel data voltage Vdata, the OLED anode voltage is increased due to increasing of the pixel data voltage, and the maximal brightness remains unchanged. Compared with the prior pixel circuit, contrast of OLED light emitting can be significantly increased. Particularly, when common cathode voltage Vcom needs to be adjusted to acquire high current output in order to acquire high brightness, the circuit does not significantly increase the minimal current outputted by the pixel, and thus, high contrast of the OLED in a high brightness state can be realized.

The invention relates to an automatic gain control circuit of multistage high dynamic range used in an ultrasonic distance measurement, which comprises n stages of sequentially and serially connected amplifying circuits; the input terminal of a first stage is connected with an input signal; the nth output forms an output signal which goes through sequentially a serially connected sampling circuit, a PID circuit and an amplitude limiter circuit, and then is respectively connected with each technotron; and the signal input terminal of the PID circuit is also connected with a given circuit. Each stage of amplifying circuit comprises an operational amplifier, non-inverting input terminals and inverting input terminals of all the operational amplifiers are respectively connected with the drain electrode of one technotron, the source electrode of each technotron is grounded, the grid electrode of the technotron connected with the inverting input terminal of the operational amplifier is connected with the output terminal of the amplitude limiter circuit, and the grid electrode of the technotron connected with the non-inverting input terminal of the operational amplifier is grounded. The control circuit can lead the amplification times to be stabilized in a given value. Simultaneously, the dynamic range is improved by adopting multistage amplification, and the gain is controlled by adopting a voltage controlled resistor so as to lead the gain to be stepless adjustable.

The invention discloses a universal memory device simulator. The universal memory device simulator is characterized by comprising a voltage-control floating ground impedance conversion module and a current integration module; the voltage-control floating ground impedance conversion module is used for implementing linear voltage-control resistance, voltage-control capacitance and voltage-control inductance, the current integration module is used for implementing current integration operation, the voltage-control floating ground impedance conversion module comprises a first current feedback operational amplifier, a second current feedback operational amplifier, a third current feedback operational amplifier, a fourth current feedback operational amplifier, a field-effect transistor, a first resistor, a second resistor, a first impedance component and a second impedance component, and the current integration module comprises a fifth current feedback operational amplifier, a capacitor and a direct-current voltage source. The universal memory device simulator has the advantages that the impedance components with different properties can access the universal memory device simulator under the conditions that circuit topological structures are unchanged, accordingly, memristor, memcapacitor and meminductor can be respectively implemented, and the integral universal memory device simulator can be implemented by the aid of only few devices and is simple in structure, low in production cost and wide in application range.

An oscillator produces an oscillator output signal usable as a clock signal, otherwise as a frequency reference on an integrated circuit. The oscillator includes an RC network with a voltage-controlled element, such as a voltage-controlled resistor, voltage-controlled capacitor or a combination including a voltage-controlled resistor and voltage-controlled capacitor. Also, a tunable element having an adjustable resistance determined by a first static parameter is included in the RC network. The oscillator also includes a feedback circuit which can include a frequency-to-voltage converter. The feedback circuit generates a control signal for the voltage-controlled element. The feedback circuit includes a feedback reference circuit having a reference output determined by a second static parameter, and a loop amplifier responsive to the reference output and the oscillator output signal.

The present invention provides one kind of surge current preventing and time sequence controlling device and method for plug-and-play electronic equipment. The device includes voltage controlled resistance unit connected serially to the power source input end of the electronic equipment; and controller with control end connected to the control end of the voltage controlled resistance unit to control the equivalent resistance, which is controlled to be relatively great while the electronic equipment is accessed to the power source and relatively small after preset time. The controller includes resistor and capacitor and controls the control voltage of the control end via controlling the charge and discharge of the capacitor. The method includes the following steps: determining the sequence of applying different power voltages to the electronic equipment; judging the plugging of electronic equipment; and lowering the limiting resistances serially connected to the input power sources in the sequence.

The invention discloses an annular high-speed voltage-controlled oscillator. The annular high-speed voltage-controlled oscillator is formed by series connection of four levels of delay units, wherein the negative output end (Vout-) of each level of delay unit is connected with the positive input end (Vin+) of a corresponding next level of delay unit, the positive output end (Vout+) of each level of delay unit is connected with the negative input end (Vin-) of a corresponding next level of delay unit, the negative output end (Vout-) of the last level of delay unit is connected with the negative input end (Vin-) of the first level of delay unit, and the positive output end (Vout+) the last level of delay unit is connected with the positive input end (Vin+) of the first level of delay unit. According to the annular high-speed voltage-controlled oscillator, an active electrical inductance structure is additionally arranged based on traditional delay units, a pair of PMOS tubes with grid electrodes connected to the ground are additionally arranged at a load end, therefore, oscillation of a circuit within the whole voltage range is guaranteed, extra electric currents can be provided for the circuit, and the oscillation frequency is improved; a control voltage is connected to the grid electrodes of the pair of PMOS tubes so that the frequency of the delay units can be controlled, and the PMOS tubes serve as voltage-controlled resistors and are used for adjusting the oscillating frequency.

The invention relates to a multifunctional internal combustion arc welding generator. The generator comprises an internal combustion engine, a generator rotor, a trigger circuit, a silicon controlled rectifier switch, a three-phase bridge rectifier, an auxiliary power supply rectifier circuit, an excitation current adjusting circuit, a generator stator, a first switch tube T1, a second diode D2, a first capacitor C1, a first diode D1 and a chopping main loop. The invention provides a structure of a voltage controlled resistor and a control mode aiming at the problem of difficulty in parallel current sharing of a chopping switch tube; the controlled resistor is controlled by an outer ring negative feedback control loop consisting of a photoelectric coupler, an outer ring control circuit, an outer ring given circuit, an outer ring hall current sensor and a voltage sampling circuit; a constant current, constant current and out-pulling and flat hard external characteristic curve is outputby selecting and switching a feedback signal output by the outer ring hall current sensor and the voltage sampling circuit; thus the requirements of argon arc welding, low-hydrogen electrode manual arc welding and cellulose electrode vertical down welding on the external characteristic curve and the welding process performance of a welding machine are met.

A current source for providing a current proportional to absolute temperature (a PTAT current) with high precision is implemented using only one off-chip component. The current source utilizes a bandgap voltage, a voltage related to a current proportional to absolute temperature and a constant current to bias a pair of voltage controlled resistive devices. In operation, a known resistance is derived by applying a constant voltage across and a constant current through a first voltage controlled resistive device. A control voltage for maintaining the constant current through the first voltage controlled resistive device is applied to control the second voltage controlled resistive device, thereby generating the highly precise PTAT current at the second voltage controlled resistive device. In one embodiment, the current source uses only one off-chip resistor in a constant current source for generating the constant current.

A current regulating apparatus capable of regulating an electrical current with a high level of precision and over a wide range of voltages includes a first depletion mode field-effect transistor (FET), a second depletion mode FET, and a fixed resistor. The second depletion mode FET and fixed resistor are connected in series and across the gate-source terminals of the first depletion mode FET. The first depletion mode FET operates as an adjustable current source while the second depletion mode FET is controlled to operate as a voltage controlled resistor. The magnitude of current regulated by the current regulating apparatus is determined based on both the resistance of the fixed resistor and a current-setting control voltage applied to the gate of the second depletion mode FET. Various precision values of regulated current can be realized by simply changing the current-setting control voltage.

A gain control circuit for generating a differential output signal in response to a differential input signal with a gain controlled by an input control signal employs two asymmetric field effect transistors (FETs) as a linear, voltage-controlled resistor. The FETs are interconnected drain-to-source with the control signal being applied to their gates so that their combined channel current is a substantially linear and symmetric function of the input control signal voltage. The gain control circuit includes two bipolar transistors, with the differential input signal being applied across their bases and the differential output signal being developed across their collectors. A resistor links the emitters of the two transistors, sources are applied to the emitters, and a pair of resistors links each collector to a source of bias voltage. The FET-based voltage-controlled resistor may be connected either between the collectors or between the emitters of the two transistors. When connected between the collectors, output signal distortion due to any input signal common mode component is reduced.

A high voltage power supply for use in a system such as a microfluidics system, uses a DC-DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC-DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

The invention discloses an extremely-simple floating ground charge-controlled memristor circuit simulation model. The model comprises a port a, a port b, a voltage-controlled resistor UR, a resistor R, a current-controlled voltage source IU and a voltage integrator A; the voltage-controlled resistor UR comprises a voltage control end uc and a controlled resistor Ru; the resistance value of the controlled resistor Ru in the voltage-controlled resistor UR is controlled by the voltage value of the voltage control end uc; the current-controlled voltage source IU comprises a current control end i and a voltage source output end ui; the voltage value of the voltage source output end ui in the current-controlled voltage source IU is controlled by the current value of the current control end i; and the voltage integrator A comprises a voltage input end ui and a voltage output end uc. According to the floating ground charge-controlled memristor circuit simulation model provided by the invention, electrical characteristics of the ports a and b are equivalent to the characteristics of the ports A and B of a memristor M; only four elements existing in simulation software need to be used; and besides, the floating ground charge-controlled memristor circuit simulation model is a two-port model, thus the complexity and the number of components of the existing charge-controlled memristor circuit simulation model are further reduced, and the model has the advantages that the grounding of one end is not required, the change range of the memristance is flexible, and the working voltage rangeis wide.

The present invention discloses a limiting oscillation circuit. (110) for generating an oscillation signal; a pulse width modulation circuit (120) for generating a pulse width modulation signal based on the amplitude of the oscillation signal; a low pass filter circuit (130) for generating a pulse width modulation signal, (140) for controlling the voltage-controlled resistance circuit (140) for controlling the voltage-controlled voltage signal based on the control of the DC-controlled voltage signal, and a voltage-controlled voltage signal (140) for controlling the voltage- The resistance value of the voltage-controlled resistance circuit (140) is changed to control the amplitude of the oscillation signal. The limiting oscillation circuit of the embodiment of the present invention can improve the performance of the limiter oscillation circuit.

The invention provides an electronic device provided with several ICs designed to reduce circuit space by reducing data transmission paths for connecting an external apparatus for developing or debugging software written into the several ICs and prevent misoperation of the device due to data collision on the data transmission path to which the external apparatus is connected. By connecting a connector for connection of a PC to a data reception line and data transmission line which connect a main microcontroller, DVD microcontroller and HDD microcontroller, data transmission paths to connect the PC are reduced and by controlling through voltage control resistors so that the signal level generated at an RXD terminal differs between times of data collision and normal operation and any one of signals of the DVD microcontroller, HDD microcontroller and PC can be read, misoperation in the event of data collision is prevented.

Voltage-controlled semiconductor structures, voltage-controlled resistors, and manufacturing processes are provided. The semiconductor structure comprises a substrate, a first doped well, and a second doped well. The substrate is doped with a first type of ions. The first doped well is with a second type of ions and is formed in the substrate. The second doped well is with the second type of ions and is formed in the substrate. The first type of ions and the second type of ions are complementary. A resistor is formed between the first doped well and the second doped well. A resistivity of the resistor is controlled by a differential voltage. A resistivity of the resistor relates to a first depth of the first doped well, a second depth of the second doped well, and a distance between the first doped well and the second doped well. The resistivity of the resistor is higher than that of a well resistor formed in a single doped well with the second type of ions.

The invention relates to the technical field of power electronics, in particular to a stable-loop power system. The stable-loop power system comprises a pulse width modulation driver, a P-channel metal-oxide-semiconductor (PMOS) tube, an N-channel metal-oxide-semiconductor (NMOS) tube, a first comparator, a voltage control resistor and a current-limiting protection circuit, wherein the voltage control resistor comprises a first connection end, a second connection end and a central tap control end, the first connection end is connected with a comparison output end, the second connection end isconnected with a first capacitor, the central tap control end is connected with the comparison output end, the voltage control resistor is used for adjusting a resistance value between the first connection end and the second connection end according to a comparison result voltage signal received by the central tap control end, and the resistance value is in negative relation with a voltage value of the comparison result voltage signal. By the stable-loop power system, relatively high loop stability can be ensured, and high reliability is achieved.

A gate driving circuit is connected to a main switching element. The gate driving circuit includes a gate resistor. The gate resistor includes a voltage controlled resistor of which a resistance value is able to be continuously changed. A switching power supply device includes a gate driving circuit, a main switching element, and a freewheeling diode connected in reverse parallel to the main switching element.

A limiting current circuit that has output short circuit protection is connected to an external voltage source and comprises an output terminal, an input current unit, a driving transistor, a voltage control resistor, a voltage control transistor and a delay unit. The output terminal is connected to a load and has an output current. The driving transistor has an internal resistance, a drain current and a gate voltage. The voltage control resistor has a resistor voltage. The voltage control transistor has an internal resistance and a parasitic capacitance. The delay unit makes the resistor voltage charging the parasitic capacitance to extend the period of lower internal resistance of the voltage control transistor and the period of higher internal resistance of the driving transistor, makes the internal resistance of the voltage control transistor is less than the internal resistance of the driving transistor when the load is shorted.

The invention discloses a voltage fractional order integral control memristor. The memristor comprises a Pin a, a Pin b, voltage-controlled resistor UR. a resistor R and a voltage fractional integrator A, a voltage control resistor UR comprising a voltage control terminal uc and a controlled resistor Ru, a resistor value of the controlled resistor Ru in the voltage control resistor UR being controlled by a voltage value of the voltage control terminal uc, and a voltage fractional integrator A comprising a voltage input terminal u and a voltage output terminal uc. This voltage fractional-orderintegral controls the memristor pin a. The electrical characteristics of B are equivalent to the characteristics of A and B pins of the magnetron memristor W. It is two pins, and further reduces the complexity and the number of components of the existing voltage fractional-order integral control memristor. It has the advantages of flexible range of memory resistance value, no ground limit, wide operating voltage range and easy to understand.

The invention discloses a voltage-controlled resistor circuit which comprises a resistor R1, a resistor R2, a current transmitter U1 and a multiplier M1. The invention aims to solve the problem that the existing adjustable resistor contains a mechanical structure or the resistance value cannot be continuously changed or the adjustable range of the resistance value is narrow. The electrical characteristics of the ports a and b are equivalent to the resistance characteristics, the change of the resistance value is controlled by the voltage uc(t), only four components need to be used, and the device has the advantages of being simple in structure, convenient to implement, free of mechanical parts, capable of continuously changing the resistance value and large in resistance value adjusting range. The voltage-controlled resistor circuit can be widely applied to various circuit design occasions needing the adjustable resistor (especially a voltage-controlled resistor).

Structures and methods for providing a temperature independent constant current reference are provided. A constant Gm circuit is disclosed with embodiments including a voltage controlled resistor providing a current into a current mirror, the current mirror sinking a reference current at its output. By providing a feedback loop that controls the voltage controlled resistor, a temperature compensated circuit may be obtained. The temperature dependence of the voltage controlled resistor is positive and the feedback circuitry maintains this resistor at a value that compensates for the negative temperature dependence of the current mirror circuit. The reference current is thus obtained at a predetermined level independent of temperature. A method for providing a reference current is disclosed wherein a voltage dependent resistor is provided supply current to a current mirror, the voltage dependent resistor receiving a feedback voltage from the current mirror and the feedback controlling the resistor so that a temperature independent reference current is obtained.

The invention discloses a current fractional order integral control type memristor, which includes a pin a, a pin b, a voltage-controlled resistor UR, a resistor R, a current controlled voltage sourceIU and a voltage fractional integrator A, the voltage-controlled resistor UR includes a voltage control terminal uc and a controlled resistor Ru, A resistance value of a controlled resistor Ru in a voltage controlled resistor UR is controlled by a voltage value of a voltage control terminal uc, the current control voltage source IU comprises a current control terminal i and a voltage source output terminal ui. The voltage value of the voltage source output terminal ui in the current control voltage source IU is controlled by the current value of the current control terminal i. The voltage fractional integrator A comprises a voltage input terminal ui and a voltage output terminal uc. The electrical characteristics of the pins a and b of the current fractional-order integral control memristor are equivalent to those of the pins A and B of the memristor M. The current fractional-order integral control memristor is two pins, which further reduces the complexity and the number of components of the existing current fractional-order integral control memristor. The current fractional-order integral control memristor has the advantages of not requiring one end of the pins to be grounded, flexible variation range of the memristor value, and wide working voltage range.

The invention discloses a new and original voltage variable resistor VVR with input and output ports and a first input and second input for control signals to set the impedance between the input and output ports as desired over a certain range and, thus, to optimize the operation of the VVR from the transmitter device control viewpoint as regards both the linearity and minimum impedance. The invention further discloses a method for controlling a VVR and a cellular radio system terminal.

The invention discloses a silicon carbide Schottky diode-based Spice model and a construction method thereof. The model comprises a voltage-controlled capacitor, a voltage-controlled resistor, a voltage-controlled body resistor, and a contact resistor, wherein the voltage-controlled capacitor is used for indicating the depletion layer capacitance of the silicon carbide Schottky diode; the voltage-controlled resistor is connected with the voltage-controlled capacitor in parallel and used for indicating the depletion layer current of the silicon carbide Schottky diode; the voltage-controlled body resistor is in series connection with parallel connection nodes of the voltage-controlled capacitor and the voltage-controlled resistor, and used for indicating the body resistance of the silicon carbide Schottky diode; the contact resistor is connected with the voltage-controlled body resistor in series. The silicon carbide Schottky diode-based Spice model disclosed by the invention has the advantage that the obtained diode dynamic curve is well matched with the experimental data. The model can be used for evaluating dynamic performance of the diode accurately and also used for guiding design and application of the silicon carbide Schottky diode.

The invention discloses a very simple floating magnetic control memristor circuit simulation model which comprises a port a, a port b, a voltage controlled resistor UR, a resistor R and a voltage integrator A. The voltage controlled resistor UR comprises a voltage control end uc and a controlled resistor Ru; a resistance value of the controllable resistor Ru in the voltage controlled resistor UR is controlled by a voltage value of the voltage control end uc; and the voltage integrator A comprises a voltage input end u and a voltage output end uc. Electrical characteristics of the ports a and bof the floating magnetic control memristor circuit simulation model are equivalent to characteristics of A and B ports of a magnetic control memristor W, only needs to use existing three elements insimulation software, and is a two-port model; complexity and the element number of an existing magnetic control memristor circuit simulation model are further reduced; and the very simple floating magnetic control memristor circuit simulation model has the advantages of flexible memristive value changing range, no grounding limitation, wide working voltage range and easiness for understanding.