2764 results about "Operational amplifier" patented technology

The invention discloses a high-precision current detection circuit calibration system, and belongs to the technical field of current detection circuit calibration. Comprising a shunt resistor, a Hall sensor array, a chopping amplifier, a low-noise operational amplifier, a temperature sensor, an ADC acquisition unit, an RC low-pass filter, a signal conditioning unit, a main control unit, an environmental parameter adaptive compensation module and a gain adaptive adjustment module. After an original signal is obtained from a multi-channel sensor, a dynamic error model is constructed in combination with temperature data, a long-term imbalance trend is extracted by using a moving average or median filtering algorithm, and real-time compensation is performed through a pre-calibrated temperature-drift function, so that the system maintenance period is remarkably prolonged.

The embodiment of the invention provides a closed-loop control method for power driving and protection, and the method comprises the steps: constructing a voltage feedback type circuit through a high-speed operational amplifier, and forming a closed-loop gain structure through a feedback network of the voltage feedback type circuit; the load current of the output end of the voltage feedback type circuit is monitored in real time, and when the load current exceeds a first set threshold value, a protection mechanism is triggered to turn off the output stage; the power-on surge current is limited through the soft start control circuit; phase information of a load reflection coefficient is obtained, an inductance / capacitance combination of the variable dynamic impedance matching network is selected according to phase information table look-up, inductance / capacitance parameters are switched through a relay, and the transmission standing-wave ratio between the power amplifier and a load is optimized; monitoring the temperature of the radiating fin of the power tube, and dynamically adjusting the resistance value of the feedback network; and performing cooperative control of short-circuit protection, over-temperature protection and surge suppression according to the priority. According to the embodiment of the invention, the performance bottleneck in a load fluctuation scene is broken through.

The invention discloses a high-voltage power amplifier with an over-temperature and over-current protection circuit, and relates to the technical field of integrated circuits. The high-voltage operational amplifier comprises a high-voltage operational amplifier core unit and a self-adaptive protection circuit unit, the high-voltage operational amplifier core unit comprises a rail-to-rail input stage, a gain amplification stage and an AB type push-pull output stage which are sequentially cascaded, and the AB type push-pull output stage comprises a PMOS upper power tube and an NMOS lower power tube; the self-adaptive protection circuit unit comprises a PMOS (P-channel Metal Oxide Semiconductor) current-limiting protection circuit, an NMOS (N-channel Metal Oxide Semiconductor) current-limiting protection circuit and an over-temperature protection circuit; the PMOS current-limiting protection circuit is used for generating a high-voltage domain over-current control signal when the power tube on the PMOS is over-current; the NMOS current-limiting protection circuit is used for generating a low-voltage domain overcurrent control signal when the NMOS lower power tube is in overcurrent; the over-temperature protection circuit is used for generating high-voltage domain over-temperature turn-off signals and low-voltage domain over-temperature turn-off signals when the amplifier is over-temperature; and finally, carrying out logic synthesis on the corresponding over-current control signal and the over-temperature turn-off signal to generate a gate clamping signal.

The invention discloses a band-gap reference source high-order curvature compensation method based on an operational amplifier, and belongs to the technical field of high-precision analog integrated circuit design, and the method comprises the steps: generating an absolute temperature proportion PTAT current and an absolute temperature complementary CTAT current; generating a high-order curvature compensation voltage based on the PTAT current and the CTAT current; amplifying the generated high-order curvature compensation voltage through an operational amplifier, and superposing the amplified high-order curvature compensation voltage to a band-gap reference output stage to obtain compensated band-gap reference output voltage; and carrying out band-gap reference output calibration on the compensated band-gap reference output voltage so as to ensure that the temperature drift coefficient of the output band-gap reference voltage in the preset temperature range is smaller than a preset threshold value. According to the invention, high-order elimination of base-emitter voltage nonlinearity can be realized in a wide temperature range, and a relatively low temperature coefficient and low noise are achieved.

The invention provides a signal acquisition system of a photoelectric detector. In the signal acquisition system, a transimpedance pre-amplification circuit is arranged at the output end of the photoelectric detector, and a passive high-pass filter circuit is connected between the transimpedance pre-amplification circuit and a post-voltage amplification circuit. And a feedback network is formed in the transimpedance pre-amplification circuit and is used for converting a current signal output by the photoelectric detector into a proportional first voltage signal and outputting the proportional first voltage signal. The filter circuit is a third-order LC high-pass filter circuit and is used for suppressing direct current, low frequency and self-beat frequency components and keeping a 10-90MHz pass band flat. The rear voltage amplification circuit adopts a voltage amplification structure of a voltage operational amplifier, the voltage gain Av is 6-10, and the super-band gain is limited through a shunt capacitor. According to the embodiment of the invention, through the structure and parameter setting, the noise gain peak value is suppressed, and the system stability is improved.

The invention discloses an ultrahigh-precision low-noise band-gap reference circuit, and relates to the technical field of integrated circuit design, the ultrahigh-precision low-noise band-gap reference circuit comprises a starting turn-off circuit, a reference core circuit, a high-order temperature compensation circuit and a digital trimming circuit, the starting turn-off circuit is connected with the reference core circuit, and the high-order temperature compensation circuit is connected with the digital trimming circuit through a Brokaw type band-gap reference topological structure. Accurate compensation of the voltage is achieved through deep negative feedback of the operational amplifier and a high-order temperature compensation circuit, and the temperature drift of the reference voltage is as low as 0.5-2 ppm / DEG C (-40 DEG C to 130 DEG C) and is increased by 5-10 times compared with a traditional band-gap reference (5-10 ppm / DEG C). The power consumption of the system can be saved by turning off the circuit when the circuit is not used, meanwhile, the digital trimming module is added to replace laser trimming in traditional engineering, the upper limit of the trimming range is improved, high-order temperature compensation and the digital trimming circuit are introduced, the precision of output voltage is improved, different devices are replaced, and the noise of the circuit is reduced. The problems that a traditional high-voltage band-gap reference temperature coefficient is high and noise is large are solved.

The invention relates to the technical field of pulse electric field measurement, and discloses a time drift compensation method of a pulse electric field measurement system based on model parameterization. According to the method, a parameterized model is constructed in simulation software, and the parameterized model is additionally provided with two servo zeroing compensation circuits on the basis of an original measurement system, and the two servo zeroing compensation circuits are connected to the output ends of two in-phase operational amplification circuits respectively to form a negative feedback loop used for dynamically suppressing low-frequency baseline drift; acquiring electric field time domain waveform data of the output end of the third in-phase operational amplifier circuit; calculating a transfer function of a pulsed electric field measurement system in the parameterized model, converting the transfer function from a frequency domain state to a time domain state through inverse Fourier transform, and then performing deconvolution on the transfer function of the time domain state and electric field time domain waveform data to obtain real electric field intensity; according to the invention, time drift caused by operational amplifier input imbalance, power supply fluctuation and temperature change is automatically compensated in real time, and the stability and precision of system measurement are improved.

The invention belongs to the technical field of analog integrated circuit design and memory read-write, and provides a multi-valued RRAM read-write circuit with a write-and-read function. The multi-valued RRAM read-write circuit is a multi-port device capable of performing read-write simultaneously, in write operation, a low dropout regulator is utilized to provide voltage for the RRAM circuit and the standard resistance circuit, mirror current is generated, the resistance value of the RRAM is set to be the total resistance of the standard resistance circuit, an operational amplifier is connected into the circuit through a CMOS switch, and feedback is formed to stabilize the voltage at the two ends of the RRAM; and in the read operation, the CMOS switch is used for disconnecting the operational amplifier, and the voltage at the two ends of the RRAM device is directly read. Compared with an existing multi-valued read-write circuit, the multi-valued RRAM read-write circuit has the advantages that write-and-read multi-valued RRAM read-write is realized, and meanwhile, the read-write circuit is not separated, so that the write-in speed is increased, and the area of the read-write circuit is saved.

The invention discloses a left auricle plugging device provided with a real-time atrial pressure monitoring chip, and particularly relates to the technical field of left auricle plugging, the left auricle plugging device comprises a plugging device body and a connector, the top end of the connector is provided with a signal supply module, and the signal supply module is located in the plugging device body; according to the left atrial appendage plugging device, after the inductor in the nut generates a voltage signal, the signal can be transmitted to the low-noise operational amplifier and amplified, meanwhile, the electromagnetic interference between the noise of a circuit and the outside world is restrained, and the plugging device can be used for plugging the left atrial appendage of the left atrial appendage of the left atrial appendage. The physical deformation is converted into corresponding electric signals, the electric signals are transmitted to an in-vitro receiving terminal through an antenna, and a doctor can indirectly judge the recovery condition of the atrial contraction function of the patient according to the pressure signal trend.

The utility model relates to the technical field of battery management, and discloses an ideal diode circuit and a battery management system, and the ideal diode circuit comprises a current collection module which is connected between the negative electrode of a battery interface and the negative electrode of a charging interface and is used for collecting current; one end of the operational amplifier module is connected between the cathode of the battery interface and the current acquisition module, and the other end of the operational amplifier module is connected between the current acquisition module and the cathode of the charging interface; the input end of the MOS driving module is connected with the operational amplification module and the current acquisition module, and the output end of the MOS driving module is connected with the negative electrode of the charging interface; wherein the operational amplification module amplifies and processes an acquisition signal of the current acquisition module, and controls the MOS driving module to act. By designing the current acquisition module, the operational amplification module and the MOS driving module, after the mode is adopted to replace a power diode, the occupied space is compact, and the overall design cost is low.

The invention discloses a method for effectively simulating general quantum computing based on a classical circuit network, and relates to the technical field of quantum computing simulation, and the method comprises the following specific steps: converting data into a voltage signal through input voltage coding, constructing a single-bit gate and a two-bit gate by using an operational amplifier and an analog multiplier, and constructing a single-bit gate and a two-bit gate; according to the invention, the general quantum computation is simulated by a classical circuit network, an n-bit unitary matrix is decomposed and reconstructed by means of input voltage coding quantum state and voucher / two-bit gate modular design, and the high-efficiency simulation of general quantum computation is realized. Quantum gate linear transformation is reproduced, quantum calculation universality is achieved, voltage signals and data are converted through a reflection formula, signal distortion is avoided, multi-level gate circuit cascading is supported, and a flexible and stable platform is provided for quantum algorithm verification and the like.

The invention discloses an environment-emotion gradient association memristive neural network circuit based on a TAP cell regulation mechanism. The environment-emotion gradient association memristive neural network circuit is composed of a hippocampus module and an amygdala kernel module. The hippocampus module comprises an environment recognition neuron module and an emotion generation neuron module; the environment recognition neuron module and the emotion generation neuron module are each composed of a weight regulation and control module adj based on a TAP cell regulation mechanism, an adder, a memristor, a resistor, an operational amplifier, a function module ABM1 and a sampling holder. Wherein the weight regulation and control module adj is composed of a voltage-controlled switch, a summator, a function module ABM2 and a function module ABM3. The almond kernel module is composed of a weight regulation and control module adj, a memristor, a resistor, an operational amplifier and a sampling holder. The provided circuit simulates the hippocampus and amygdala nucleus of the brain in structure, the regulation principle of TAP cells on neural stem cells is used for reference in a weight regulation mechanism, and bidirectional gradient associated memory of the environment and the emotion can be achieved.

The invention is suitable for the technical field of electronic circuits, and provides a wide-load-capacitance low-dropout linear regulator circuit, a power supply device and electronic equipment. The wide load capacitance low dropout linear regulator circuit comprises a bias module, a first operational amplifier module, a second operational amplifier module, a third operational amplifier module, a first compensation module and a second compensation module, and the first operational amplifier module is electrically connected with the bias module, the second operational amplifier module and the first compensation module. The third operational amplifier module is electrically connected with the second operational amplifier module, the second compensation module and the first operational amplifier module. A first zero point generated by the first compensation module is used for compensating the second pole, and a second zero point generated by the second compensation module is used for compensating the third pole. Therefore, according to the design architecture of the wide-load-capacitance low-dropout linear voltage regulator circuit provided by the embodiment of the invention, the two zero points effectively compensate the corresponding poles, the phase margin of the circuit is remarkably improved under the wide-range load capacitance, and the stability of the circuit is enhanced.

The invention belongs to the technical field of analog integrated circuit design automation, and discloses an analog integrated circuit cross-process performance prediction method and system based on Transform transfer learning, and the method comprises the steps: 1, carrying out the preprocessing of analog integrated circuit sample data; 2, serializing the sample data according to a preset sequence, mapping each parameter into vector representation, adding a global abstract vector, and splicing according to a fixed sequence to form an input sequence; 3, encoding the input sequence to obtain an output sequence; 4, inputting the global features into the regression head network, and outputting a performance index prediction value; 5, training is carried out, network parameters obtained through pre-training of the source technology are migrated to the target technology, fine adjustment is carried out on part of network parameters of a target technology data set, and cross-technology performance prediction is achieved; and 6, performing forward reasoning on operational amplifier design parameters under a given target process according to the steps 2-4 to obtain a performance prediction result. The method improves the stability and efficiency of performance prediction.

The invention discloses a high-precision R-2R voltage type digital-to-analog converter based on a binary weighted code and a thermometer code, the digital-to-analog converter comprises a weighted resistance network, a thermometer decoder circuit and an operational amplifier module with a self-calibration function, the output of the weighted resistance network is connected with the operational amplifier module with the self-calibration function, and the output of the thermometer decoder circuit is connected with the operational amplifier module with the self-calibration function. The output of the thermometer decoder circuit is connected with a thermometer code part of the weighted resistance network, an external clock CLK signal and a common-mode voltage serve as input signals of the operational amplifier module with the self-calibration function, and an output signal of the weighted resistance network passes through the operational amplifier module with the self-calibration function to obtain final analog voltage output. The resistance network adopts a mixture of thermometer codes and an R-2R structure, static indexes of the DAC can be effectively optimized, the impedance matching problem of the resistance network is reduced, a self-calibration operational amplifier technology is further applied, the influence of offset voltage of an operational amplifier on output precision can be eliminated, and the output driving capacity of the DAC is improved.

The invention discloses an LDO (Low Dropout Regulator) circuit based on a level conversion and pre-adjustment module. The LDO circuit comprises a reference source, an error amplifier, a pre-adjustment module, a level conversion module, a power switch tube P1, a power circuit tube N1 and resistance feedback networks R1 and R2. The pre-adjustment module carries out voltage reduction processing on an input high-voltage power supply, and the level conversion module generates bias voltage according to an enable signal and the high-voltage power supply, controls a power switch and a switch in the operational amplifier, and ensures that the circuit is resistant to high voltage and extremely low in drain. The error amplifier adjusts the grid voltage of the power circuit according to the feedback and reference voltage difference value, and controls the current to stably output the voltage. And the resistance feedback network realizes closed-loop regulation of the output voltage. Under the condition that the LDO is enabled to be closed, the power tube can be ensured to be completely closed no matter the LDO is under the working voltage of 3V or 5V, so that the electric leakage condition of the LDO is greatly improved, and the LDO has the characteristic of low electric leakage.

The utility model discloses an output power detection circuit capable of accurately judging the output power of a power supply. The output power detection circuit comprises an input end positive electrode, an input end negative electrode, an output end positive electrode, an output end negative electrode, an operational amplifier and a reference voltage circuit, the input end positive electrode is connected with the output end positive electrode, the input end negative electrode is connected with the output end negative electrode through a current detection resistor R1, and the input end negative electrode is grounded; the reference voltage circuit outputs a reference voltage to the inverted input end of the operational amplifier, the positive input end of the operational amplifier is connected with the negative electrode of the output end through a resistor R2, and the positive input end of the operational amplifier is connected with the positive electrode of the output end through a resistor R3. And the operational amplifier outputs a corresponding control signal according to a comparison result of the normal-phase input end voltage and the inverted-phase input end voltage of the operational amplifier.

Embodiments of this application provide a display driver circuit, a control method for a display driver circuit, a display module, and an electronic device, and relate to the field of display technologies, to resolve a problem that an over-designed driver circuit cannot meet a low power consumption requirement. The display driver circuit is used in a display module, and may include at least one dynamic bias generator, a plurality of gamma operational amplifiers, a resistor string, and a plurality of source driving channels. The dynamic bias generator is configured to output a dynamically adjustable bias current. At least one of the plurality of gamma operational amplifiers may be electrically connected to the dynamic bias generator, and the gamma operational amplifier is configured to output a gamma reference voltage based on the bias current. The resistor string performs voltage division on output terminals of two adjacent gamma operational amplifiers.

The utility model provides a detection control circuit, a battery management circuit and a battery pack. The detection control circuit is used on a sampling line of a battery cell and connected between a positive electrode or a negative electrode of the battery cell and a sampling resistor on the sampling line, the detection control circuit comprises a resistor, a switching tube, an operational amplifier circuit and a control circuit, and when a first voltage value is larger than a preset value, the control circuit controls the switching tube to be switched off; after the switch tube is switched off for a preset time, the control circuit controls the switch tube to be switched on again; when the second voltage value is larger than the preset value, the control circuit controls the switch tube to be disconnected again, and when the second voltage value is smaller than or equal to the preset value, the control circuit controls the switch tube to be kept on. Whether abnormal surge current or short-circuit large current is generated on the sampling line is actively monitored, meanwhile, on-off control over the sampling line is achieved, the sampling line is cut off when the abnormal surge current or the short-circuit large current is generated, and the problem of device damage such as abnormal fusing of a fuse is prevented.

The utility model provides a sampling circuit, an analog circuit and electronic equipment, and the sampling circuit comprises an input processing unit which is connected with the output end of a target circuit, and is used for collecting the common-mode output voltage of the target circuit, and carrying out the sampling input processing of the common-mode output voltage, and obtaining a first operational amplifier in-phase sampling signal and a first operational amplifier anti-phase sampling signal; the signal amplification unit is connected with the input processing unit and is used for respectively amplifying the first operational amplifier in-phase sampling signal and the first operational amplifier anti-phase sampling signal to obtain a second operational amplifier in-phase sampling signal and a second operational amplifier anti-phase sampling signal; and the signal stabilization unit is connected with the signal amplification unit and the control circuit, and is used for keeping the second operational amplifier in-phase sampling signal and the second operational amplifier anti-phase sampling signal, generating a feedback signal according to the second operational amplifier in-phase sampling signal and the second operational amplifier anti-phase sampling signal, and outputting the feedback signal to the control circuit. In this way, the input impedance and the sampling precision are improved.

The invention discloses a system reference clock frequency accuracy automatic calibration circuit and a calibration method thereof, and belongs to the technical field of frequency sources, the calibration circuit comprises a first crystal oscillator, a first power divider, a second power divider, a second crystal oscillator, an analog switch, a radio frequency switch, a detector, a comparator, an FPGA controller, a digital analog converter, an operational amplifier and a temperature sensor. When an external high-precision reference clock is accessed, the FPGA controller automatically switches a frequency measurement reference, performs high-precision frequency measurement on a 100MHz signal output by the first crystal oscillator, and judges whether calibration is needed or not according to frequency offset; if calibration is needed, the output voltage of the digital-to-analog converter is adjusted, the Vc end of the first crystal oscillator is controlled after operational amplification, and frequency closed-loop adjustment is achieved. According to the method, the crystal oscillator does not need to be disassembled, calibration is rapidly completed on site, and system availability and long-term frequency stability are remarkably improved.

A compensation circuit and a display device. The compensation circuit includes a timing controller, a power management circuit, an operational amplifier circuit, and a delay circuit. The delay circuit is configured to prolong a time duration of the operational amplifier circuit in the operating state in a first stage, and the delay circuit controls the operational amplifier circuit to stop operation when the delay circuit is able to stably output a common voltage to the display panel. A time duration of outputting the common voltage to the display panel is prolonged in a second stage. When the operational amplifier circuit is in the operation state, the delay circuit stops outputting the common voltage to the display panel.

The invention belongs to the technical field of integrated circuits, and particularly discloses a numerical control programmable gain amplifier chip, which adopts an SIP (Session Initiation Protocol) packaged operational amplifier, a digital potentiometer, an input end Vin and an output end Vout, and is characterized in that an alternating current signal is input from the Vin end and is connected to an inverted input end of the operational amplifier through a capacitor C1 and an input resistor R1; a positive power supply pin of the operational amplifier is connected with a power supply positive electrode VDD, a negative power supply pin is grounded, and a VDD / 2 direct current bias voltage is obtained by an in-phase input end through a precision resistance voltage dividing network and is accessed after low-pass filtering; the high end of the digital potentiometer is connected with the Vout end, the low end is connected with the inverting input end of the operational amplifier, and a feedback path is formed through a sliding end. The digital potentiometer and the operational amplifier are integrated, high integration and modularization of the programmable gain amplification circuit are achieved, and the problems that in a traditional discrete scheme, due to analog switch conduction resistance, gain precision is insufficient, reliability of a multi-element system is lowered, and the circuit size is large are solved.

The invention discloses a ClassAB output stage bias structure based on a negative feedback loop, which belongs to the technical field of integrated circuit design and comprises a ClassAB output stage structure and a negative feedback loop floating current source structure. The ClassAB output stage structure is used for realizing the rail-to-rail output performance of the operational amplifier, and the negative feedback loop floating current source structure is used for determining the static bias current of the ClassAB output stage structure; the negative feedback loop floating current source structure comprises a floating current source structure, a static bias structure, a loop bias structure, a current reference structure and a state conversion structure. According to the invention, static bias is carried out on the ClassAB output stage through a negative feedback loop, the bias precision and good temperature drift resistance are ensured, and the problems of static bias point error, drift and the like caused by the fact that the output stage of the rail-to-rail, low-power-consumption and zero-drift operational amplifier applies traditional linear transconductance ring bias are solved.

The embodiment of the invention provides a signal processing circuit and an integrated circuit. The signal processing circuit includes: a first amplification branch including a first operational amplifier and a first resistance network connected to the first operational amplifier; a detection branch coupled to an input of the first amplification branch, the detection branch comprising a variable resistor and configured to detect a common mode component input to the first amplification branch and generate a compensation signal based on the common mode component and a resistance value of the variable resistor; and an adjustment branch coupled between the detection branch and the first amplification branch and configured to adjust the compensation signal and apply the adjusted signal to the first amplification branch to reduce an input deviation of the first operational amplifier, the input deviation being associated with a resistance mismatch and a common mode component of the first resistance network.

The invention relates to the technical field of switching power supply analog control, in particular to a control method and system for a small-duty-ratio BOOST module based on digital control, and the method comprises the following steps: S1, carrying out the sampling of the equal-proportion reduced output voltage of an operational amplifier through an ADC analog-to-digital converter, processing the sampled voltage value through a filtering algorithm to obtain an output voltage VO; and S2, carrying out calculation processing on the output voltage VO through a PID control algorithm, and obtaining an expected output voltage through a fixed-frequency adjustment duty ratio PWM and a fixed-duty ratio frequency modulation PFM. Efficient and stable voltage boosting is achieved through double-closed-loop digital control, dynamic response and anti-interference capacity are achieved, the core lies in collaborative design of power conversion and a control strategy, input direct-current voltage is boosted to higher stable output voltage, a double-closed-loop (voltage loop + current loop) control strategy is adopted, and the voltage boosting effect is achieved. And closed-loop adjustment is realized by combining PWM driving and ADC sampling.

The invention discloses an intelligent insulation parameter dynamic monitoring and regulation system based on a GD32 microcontroller, and belongs to the field of power electronic insulation monitoring. According to the system, a distributed monitoring network is constructed by taking GD32 as a core processor, a multi-channel time-sharing sampling and dynamic impedance measurement algorithm is integrated, GA / GB dual-channel independent sampling is realized by virtue of a state machine, and the sampling efficiency is improved by 80% compared with that of a traditional scheme. A programmable resistance network and a low-noise operational amplifier are adopted, 1 pF to 100 nF impedance matching and 5-200-time dynamic gain adjustment are achieved, an optical coupler switching dynamic impedance measurement method is originally created, four sets of voltage are adopted for time-sharing conduction of a solid-state relay, and 1.5% high precision is achieved through an improved voltage division model. LC-pi type filtering is adopted at a signal input end, and the high-frequency noise suppression ratio is larger than 20 dB; and a CAN module is newly added, so that a CAN2.0B extension frame and an adjustable Baud rate of 10k-1Mbps are supported. Actual measurement shows that the system can measure 10-65M omega insulation resistance in new energy and rail transit scenes, the dynamic response is smaller than or equal to 200ms, the system is suitable for the fields of medical equipment, industrial sensors and the like, and the overall performance is improved by three times compared with that of a traditional scheme.

A circuit includes a supply node receiving a supply voltage; an output node providing a regulated voltage; startup circuitry coupled to the supply node; current generator circuitry coupled to the startup circuitry and producing a current; a bandgap node coupled to bandgap circuitry to receive a bandgap voltage; multiplier circuitry coupled to the bandgap node and the current generator circuitry to receive and apply scaling to the current; a first transistor providing a threshold voltage drop across the first and second transistor nodes; a first resistive element interposed between the first transistor and the bandgap node; a second resistive element coupled between ground and the second node of the first transistor; and an operational amplifier receiving a pre-regulated voltage as a function of the bandgap voltage, the threshold voltage across the first transistor, and a voltage drop across the first and second resistive elements.

The invention provides a power supply regulating device and a voltage-adjustable power supply circuit thereof, and relates to the technical field of power supply regulation, the circuit is additionally provided with a sampling resistor, an operational amplifier unit and an MCU on the basis of keeping the original sampling partial voltage, and adjustable analog level output by the MCU is injected into a DC-DC feedback pin after being subjected to operational amplifier gain, so that the voltage-adjustable power supply circuit is formed. The potential of a feedback node is biased in a voltage superposition mode, so that the output voltage and the analog level are in an approximately linear relation; according to the invention, higher resolution adjustment can be obtained in a preset full range only by changing the DAC level or the PWM duty ratio, the gear intervals are uniform, digital potentiometers or segmented switching are not needed, the calculation is simple, the hardware cost is low, and the control is convenient. The high-precision power supply can be widely applied to occasions requiring a software controllable high-precision power supply, such as a thermal printing head test fixture, ink-jet head ink quantity control, motor torque adjustment and the like. The invention aims to solve the problems that the resolution of a low-voltage section is suddenly reduced and the fineness is insufficient due to resistance-voltage nonlinearity during wide-range voltage regulation of a traditional digital potentiometer type DC-DC feedback network.

The invention provides a logic control-based self-adaptive optocoupler compensation circuit and a switching power supply. The logic control-based self-adaptive optocoupler compensation circuit comprises a first operational amplifier circuit, a second operational amplifier circuit, a third operational amplifier circuit and a fourth operational amplifier circuit, the switching tube circuit is used for switching on or switching off a corresponding switching tube according to the level signal to match impedance access of a corresponding size; the output end of the impedance matching circuit is connected with the first input end of the photoelectric coupler, the second input end of the photoelectric coupler is connected with the output end of the feedback compensation circuit, and the current of the input end of the photoelectric coupler and the total impedance of the self-adaptive feedback compensation loop are adjusted by automatically matching different impedances. Therefore, automatic switching of different gain and bandwidth working modes of the photoelectric coupler under wide-range output is realized. According to the invention, the working current of the optocoupler is adaptively switched through the logic control circuit, and the compensation parameter of the feedback loop is dynamically optimized, so that the switching power supply can achieve the effect of high stability under the working condition of full-range output adjustment.