23 results about "Fully differential amplifier" patented technology

The invention relates to the technical field of conversion circuits, and provides a converter drift suppression front-end circuit and a drift suppression method, and the circuit comprises a first signal processing circuit and a second signal processing circuit which are symmetrically distributed, and a high-frequency path and a low-frequency path which are arranged between the first signal processing circuit and the second signal processing circuit; wherein a normal-phase input signal forms a first node signal after passing through the first signal processing circuit, and a reverse-phase input signal corresponding to the normal-phase input signal forms a second node signal after passing through the second signal processing circuit; the first node signal and the second node signal are respectively input into a normal-phase input end and an inverted-phase input end of a converter CTLE through the high-frequency path or the low-frequency path; and the low-frequency path comprises a fully differential amplifier with resistance proportion negative feedback. According to the invention, baseline drift can be effectively suppressed, so that the stability of converter receiving end signals is improved.

A fully differential amplifier is provided, comprising one or more stages and a class AB output stage. The one or more stages amplify a differential pair of input signals to produce an amplified differential pair of signals, and the class AB output stage further amplifies the amplified differential pair of signals to produce a differential pair of output signals. The class AB output stage includes a pair of differential outputs. For each of the differential outputs, the class AB output stage includes a folded network of transistors and a feedback circuit. Transistors in the folded network form a control amplifier for regulating the control inputs of the output pair, and the feedback circuit controls this control amplifier. The folded network biases a pair of output transistors in class AB.

A circuit with calibration function includes a fully differential amplifier circuit, two voltage generation circuits, two multiplexers, a comparator and a digital logic circuit. The fully differential amplifier circuit amplifies a pair of differential input voltages to generate a pair of differential output voltages. One voltage generation circuit utilizes a first current to flow through a capacitor to generate a first voltage. The other voltage generation circuit utilizes a second current to flow through a resistor to generate a second voltage. The multiplexers provide the pair of differential output voltages or the first and second voltages to the comparator according to a digital control signal. The digital logic circuit generates a first digital code to adjust a capacitance of the capacitor or a second digital code to adjust DC voltage levels of the pair of differential output voltages according to the comparison signal provided by the comparator.

The invention discloses a fully differential amplifier circuit with rail-to-rail output. The fully differential amplifier circuit comprises a main amplifier circuit, a first-stage common-mode feedback circuit, a second-stage common-mode feedback circuit and a voltage regulation circuit. The main amplifier circuit comprises a first-stage main amplifier and a second-stage main amplifier which are cascaded; the first-stage common-mode feedback circuit comprises an amplifier Af1, a first input end of the amplifier Af1 is connected to the first-stage differential output end, a second input end of the amplifier Af1 is connected with a first reference voltage end, and the amplifier Af1 compares common-mode voltage output by the first-stage main amplifier with first reference voltage VREF1 and feeds back error quantity to the first-stage main amplifier; the second-stage common-mode feedback circuit comprises an amplifier Af2; the input end of the voltage adjusting circuit is connected with the output end of the amplifier Af2, and the output end of the voltage adjusting circuit provides adjustable first reference voltage for the first reference voltage end. According to the circuit, it can be guaranteed that the output common-mode level is fast and stable, and rail-to-rail output is achieved.

A capacitive sensor detection circuit has a sensor element with a displaceable electrode, a first electrode, and a second electrode. The circuit includes a signal generation circuit that provides a modulated signal to the displaceable electrode. A fully differential amplifier is included, with input terminals connected to the first and second electrodes and output terminals for first and second output signals. The circuit has feedback capacitors between the amplifier's input and output terminals, and capacitors between the electrodes and the amplifier's input terminals. A calculation circuit is included to process the amplifier's output signals. A controller acquires the first and second output signals and, in response, provides a feedback signal. This feedback signal is supplied through the input capacitors, has the same frequency but opposite phase as the modulated signal, and is determined based on the acquired output signals.

This application discloses an acoustic Doppler receiving signal processing method and apparatus. The method includes: performing a first-stage analog coarse-tuning filtering on the received underwater acoustic signal using a low-noise tunable amplifier circuit; performing bandwidth compression filtering on the signal after the first-stage analog coarse-tuning filtering using a fully differential amplifier circuit; performing a second-stage analog fine-tuning filtering on the signal after the bandwidth compression filtering using a programmable bandpass filter; converting the analog signal after the second-stage analog fine-tuning filtering into a digital signal using a fully differential analog-to-digital converter circuit; and performing a third-stage digital fine-locking filtering on the digital signal in the digital domain using an FPGA processing circuit. Using the scheme of this application, a signal processing architecture with deep integration of analog and digital domains, step-by-step focusing, and adaptive tracking is constructed, significantly improving the efficiency and performance of capturing and accurately analyzing weak Doppler signals in complex underwater acoustic environments.

The application relates to the technical field of electronic circuits, in particular to a signal processing circuit for a high-precision leakage protector. The signal processing circuit comprises a switched capacitor full-differential amplifier unit, a voltage effective value sampling and holding unit, a zero-crossing comparator unit, a double-end to single-end amplifier unit, an overcurrent threshold comparator unit and a current source charging and discharging circuit unit. The direct current deviation caused by the full-differential amplifier can be filtered out through the switched capacitor in the application, so that the amplification precision of the signal can be effectively improved, the detection deviation can be reduced, the error of the leakage current detection can be reduced, the working temperature range of the circuit can be widened, the problem that the leakage current detection value fluctuates greatly with temperature can be solved, the circuit works more stably, meanwhile, the switched capacitor can effectively avoid high-frequency interference signals outside the switching frequency, and the electromagnetic compatibility of the circuit is improved.

The present application belongs to the technical field of analog circuit, and particularly relates to a programmable gain amplifier suitable for a high-precision ADC front end. The programmable gain amplifier of the present application adopts a whole differential structure, and comprises a whole differential amplifier. The amplifier completes the function of signal amplification, and has the characteristics of high gain and high linearity. The switches of the network of the switching feedback resistance and capacitance all adopt transmission gate switches, so as to reduce the channel charge injection effect of the switches and the nonlinearity of the on-resistance of the switches. The feedback network of the programmable gain amplifier changes the size of the feedback resistance and capacitance through the transmission gate and the resistance-capacitance combination, so as to realize the control of the gain. The input signal is amplified by the accurate amplification multiple, and meanwhile the size of the feedback resistance and capacitance is impedance-matched, so as to ensure that the-3dB bandwidth of the whole programmable gain amplifier remains basically unchanged, so that the working speed of the programmable gain amplifier under different gain conditions remains consistent, and the linearity is greatly improved.

The invention discloses a high-precision electrochemical detection system and a detection method. The system comprises a front-end circuit, a middle-end circuit and a rear-end loop, a front-end circuit converts a working electrode weak current into a voltage signal through a trans-impedance amplifier, and then the voltage signal is processed by a fully differential amplifier with a high common-mode rejection ratio; the middle-end circuit generates an adjustable bias voltage and applies the adjustable bias voltage to the other input end of the fully differential amplifier so as to compensate the offset voltage and realize single-end-to-differential conversion; the rear-end loop is used for stabilizing the potential of the reference electrode, collecting potential data in real time through the monitoring circuit, processing the potential data by the main control module, sending out a control instruction, and finally dynamically adjusting an excitation signal through the analog excitation circuit to form a stable closed loop. The invention has the advantages of high measurement precision, strong stability and strong anti-interference capability, is suitable for reliable detection of trace substances, and solves the problems of insufficient output voltage stability, low signal-to-noise ratio and susceptibility to ambient temperature interference of the existing electrochemical detection equipment in low-concentration sample detection.

This invention relates to a low-temperature drift, high-precision heat flux conversion circuit, characterized by comprising: using two operational amplifiers U1A and U1B with identical parameters on the same substrate, whose temperature drifts are similar, and setting the two operational amplifiers to be in opposite directions to cancel out the effects of their offset voltages and temperature drifts, first forming a fully differential amplifier circuit to amplify the small signal from the heat flux sensor; the amplified signal is then passed through two other operational amplifiers U2A and U2B on the same substrate to form an additive bias circuit, obtaining a high-precision voltage signal V0 with adjustable bias, low temperature drift, and low offset. The beneficial effect of this invention is that it reduces the output offset voltage, thereby reducing the impact of input offset voltage and temperature drift on the accuracy of heat flux acquisition, and improving the accuracy of heat flux sampling.

The invention discloses a current multiplexing feedback type direct current offset elimination circuit and method, and belongs to the field of direct current offset elimination. The feedback type direct current offset cancellation circuit comprises a fully differential amplifier and a DCOC feedback circuit, the fully differential amplifier is used as an input stage of the three-stage amplifier, is mainly used for amplifying a feedforward signal, and consists of R2, R3, M1, M2 and M3; and the R1, the C1, the M5 and the M6 form a DCOC feedback circuit. According to the direct-current offset elimination circuit, the problem that the direct-current offset of the circuit is too large is solved through fewer components; the feedback circuit and the feed-forward circuit share one path of current, so that extra power consumption cannot be introduced into the direct-current offset elimination circuit. According to the invention, feedback type DC offset elimination of current multiplexing can be realized, the problem of overlarge DC offset of the circuit caused by mismatching of CMOS process devices, temperature drift, process deviation and the like can be solved, and the problems of complex design, extra area introduction and power consumption of a traditional DC negative feedback type DCOC can also be solved.

This disclosure provides a deflector driver for driving a deflector in a charged particle inspection apparatus. The deflector driver may include a fully differential amplifier configured to produce a fully differential output with an absolute value greater than 100V. The fully differential output allows multiple deflector electrodes of the deflector to influence the charged particle beam of the charged particle inspection apparatus based on the fully differential output.

The present invention achieves a technology that makes it possible to independently adjust loop gains of a low-frequency path and a high-frequency path of a CMFB circuit, and that improves ease of design.　This technology provides an amplifier circuit comprising: a fully differential amplifier that amplifies a differential signal; and a common mode feedback (CMFB) circuit that stabilizes an output common mode voltage of the fully differential amplifier. The CMFB circuit has a low-frequency path that generates a first feedback signal, and a high-frequency path that generates a second feedback signal. The fully differential amplifier has a differential input transistor pair, and a tail current source that is connected to a common source of the differential input transistor pair. The tail current source is divided into a first current source and a second current source. The low-frequency path supplies the first feedback signal to the first current source and the second current source. The high-frequency path supplies the second feedback signal to the second current source.

The present invention relates to a current sensor having a differential output, and more specifically to a High-Side current sensor and an offset correction circuit thereof that uses two single-ended amplifiers in a symmetrical structure instead of using a fully differential amplifier.

In a comparator that has the function of supplying a temporary bias current to the differential pair when the output transitions, in addition to a steady bias current, the delay in the timing of the change in the relative magnitudes of the input voltages is suppressed at the timing of generating the temporary bias current. [Solution] The comparator 10 provides a temporary bias current I to the current path of the differential pair, including the input transistors 11 and 12, in accordance with the reversal of the relative magnitudes of the first input voltage V1 and the second input voltage V2 in the fully differential amplifier. B2 The system includes a second current supply circuit 52 that supplies a current. The second current supply circuit includes a first monitor transistor 45 that turns on in response to the voltage at the first node n1, and a second monitor transistor 46 that turns on in response to the voltage at the second node n2 and is connected in series with the first monitor transistor. The second current supply circuit supplies a current generated based on the through-current that occurs when both the first and second monitor transistors are turned on, as a temporary bias current.

The invention discloses a stacked two-way fully-differential amplifier, which is characterized in that the amplifier boosts the voltage of a floating node to twice VDD (Voltage Drain Drain) in a capacitor stacking manner, and two independent working voltage regions, namely 0-VDD and VDD-2VDD, are formed by utilizing a separation capacitor, so that a two-way fully-differential output structure is realized. In the circuit design, a high-gain cascode structure is also introduced, so that the performance of double-path differential output is further enhanced. Besides, the ADC system adopting the stacked double-path fully differential amplifier also realizes a double-path output architecture, and through synthesis processing of two paths of output signals, the amplitude of the output signals is effectively improved, the signal-to-noise ratio of the system is remarkably improved, and the performance of the whole system is enhanced.

The invention relates to a circuit with a correction function and a circuit correction method. The circuit with the correction function comprises a fully differential amplifier circuit, two voltage generation circuits, two multiplexers, a comparator and a digital logic circuit. The fully differential amplifier circuit amplifies a pair of differential input voltages to generate a pair of differential output voltages. A voltage generating circuit causes the first current to flow through the capacitor element to generate a first voltage. Another voltage generating circuit causes a second current to flow through the impedance element to generate a second voltage. The two multiplexers provide the pair of differential output voltages or provide the first voltage and the second voltage to the comparator according to the digital control signal, so that the comparator provides a comparison signal accordingly. The digital logic circuit generates a first digital control code according to the comparison signal to adjust the capacitance value of the capacitor element or generates a second digital control code to adjust the DC voltage level of the pair of differential output voltages.

The invention belongs to the field of temperature detection, and particularly provides a switched capacitor amplifier sampling circuit for converting differential voltage into common-mode voltage, which has the advantages of high precision and low distortion and is used for replacing a fully differential amplifier module in a temperature detection circuit. The sampling circuit of the switched capacitor amplifier comprises a sampling stage and a holding (amplifying) stage, the sampling stage synchronously stores signals and imbalance, the amplifying stage reversely superposes and counteracts, equivalent imbalance is greatly reduced, drift can be neglected, additional calibration is not needed, imbalance is prevented from covering weak signals, and precision is greatly improved; meanwhile, non-overlapping clock control is adopted, switch cross conduction is avoided through an accurate time sequence, and non-ideal factor interference is reduced; moreover, the fixed gain is realized through the capacitance proportion, a precise resistor is not needed, the linearity depends on capacitance matching, the wide gain range is realized, and the performance is stable. And in cooperation with rail-to-rail output, a wider signal range can be covered, and the requirement for full-scene signal amplification is met.

The application relates to the technical field of circuit design, and provides a signal conditioning circuit suitable for bridge output and a high-precision signal sampling circuit, which is designed by selecting a high-performance instrument amplifier and a full-differential amplifier based on the bridge characteristics, a first-stage amplification filtering composed of an instrument amplifier, a first low-pass filter and an inverting amplifier, and a second-stage amplification filtering composed of a full-differential amplifier, two second low-pass filters and an output-stage low-pass filter are designed, the first-stage amplification filtering generates extremely high input impedance, so that the influence of bridge balance can be ignored, voltage difference is effectively extracted from a direct current component for conversion and amplification, a rail-to-rail full-differential amplifier design is adopted to realize stable full-scale output of signals and provide good input matching for an ADC chip, the signal resolution of 10 uV and below can be realized, and the signal sampling of the signal below uV can be realized.

The application discloses a kind of wideband transimpedance amplifiers based on double loop capacitance positive feedback, including first input capacitor C in1 , second input capacitor C in2 , first fully differential amplifier A1, second fully differential amplifier A2, first feedback resistance R F1 , second feedback resistance R F2 , first feedback capacitor loop, second feedback capacitor loop.A kind of wideband transimpedance amplifiers based on double loop capacitance positive feedback provided by the application, only by introducing two feedback capacitor loop can improve the bandwidth of transimpedance amplifier and its core amplifier, also can increase transimpedance gain without changing the bandwidth of transimpedance amplifier, and reduce its noise.The application does not increase the static power consumption of circuit, also does not need to use inductance, is conducive to reduce the power consumption of wideband optical receiving circuit and save chip area.

The present disclosure provides a deflector driver for driving a deflector of a charged particle inspection apparatus. The deflector driver may include a fully differential amplifier configured to generate a fully differential output having an absolute value greater than 100 V. Wherein the fully differential output may enable the plurality of deflector electrodes of the deflector to influence the charged particle beam of the charged particle inspection apparatus based on the fully differential output.

The invention belongs to the technical field of laser driving, and relates to a laser driving system with optical waveform feedback. The system comprises a driving circuit, an optical feedback circuit and a control system, the driving circuit is a multi-phase interleaved BUCK circuit and is used for providing large-current and low-ripple driving pulse current for the laser; the optical feedback circuit comprises a photoelectric detector, a trans-impedance amplifier and a fully differential amplifier, and is used for collecting a laser signal output by the laser and converting the laser signal into an electric feedback signal; the control system comprises an FPGA, a high-speed ADC and an upper computer. The FPGA comprises a waveform processing unit, a DDS (Direct Digital Synthesizer) module, a digital integrator and a SerDes module; and the FPGA realizes laser waveform high-fidelity driving and stable output power control through double closed-loop control. According to the invention, a waveform feedback technology is adopted, high-fidelity driving of a laser output waveform is realized, and the stability of output power can still be maintained after waveform adjustment.

The application belongs to the technical field of laser driver, and relates to a laser driver system with optical waveform feedback. The system comprises a driving circuit, an optical feedback circuit and a control system; the driving circuit is a multi-phase staggered parallel BUCK circuit, which is used for providing a large-current and low-ripple driving pulse current for the laser; the optical feedback circuit comprises a photoelectric detector, a transimpedance amplifier and a full-differential amplifier, which are used for collecting a laser signal output by the laser and converting the laser signal into an electric feedback signal; the control system comprises an FPGA, a high-speed ADC and an upper computer; the FPGA comprises a waveform processing unit, a DDS module, a digital integrator and a SerDes module; the FPGA realizes high-fidelity driving of the laser waveform and stable control of the output power through double-loop control. The application adopts the waveform feedback technology, realizes high-fidelity driving of the laser output waveform, and can still maintain the stability of the output power after the waveform is adjusted.