44 results about "Fully differential amplifier" patented technology

The invention relates to the technical field of integrated circuit design, and particularly discloses a low-noise programmable amplifier, which comprises a first fully-differential amplifier, a second fully-differential amplifier, a third fully-differential amplifier and a fourth fully-differential amplifier, the second fully differential amplifier comprises a pair of differential input ends and is electrically connected with the first fully differential amplifier through an interstage chopper switch; a pair of input chopping switches, wherein the input end of each input chopping switch is electrically connected with a differential input signal; the output end of each output chopping switch is electrically connected with the output end of the second fully differential amplifier; the input capacitance network is positioned between the pair of input chopping switches and the two pairs of differential input ends; the feedback capacitance network is positioned between the pair of output chopping switches and the two pairs of differential input ends; and the plurality of zeroing switches are positioned between the input and the output of the first fully differential amplifier. The two transconductance amplifiers in the first fully-differential amplifier share the same current, the overall transconductance is doubled compared with single-pair differential input, and the noise of the amplifier is reduced.

A fully differential switched capacitor amplifier receives a differential analog signal from a differential input terminal, amplifies the differential analog signal, and outputs an amplified signal from a differential output terminal. The fully differential switched capacitor amplifier includes: a sampling capacitor that respectively samples the differential analog signal input from the differential input terminal; a differential input switch connected to a path for inputting the differential analog signal between the differential input terminal and the sampling capacitor; a fully differential amplifier that amplifies the differential analog signal input to the sampling capacitor; and a differential input resistor connected between the differential input switch and the sampling capacitor.

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.

The invention discloses a low-noise audio acquisition circuit based on an underwater glider. The low-noise audio acquisition circuit comprises a controller module used for controlling all modules and data transmission; the data storage module is used for storing effective data transmitted by the controller module and the processor module; the data interaction module is used for collecting state information of the underwater glider and sending the state information to the data storage module; the data processing module comprises an operational amplifier, a gain amplifier, a fully differential amplifier and a hydrophone for collecting audio information; audio information collected by the hydrophone is firstly subjected to preliminary amplification and impedance matching through the operational amplifier, then enters the gain amplifier to be subjected to flexible gain adjustment and signal optimization, is further amplified through the fully differential amplifier and inhibits common-mode interference, and finally, the audio information is transmitted to the analog-to-digital converter to complete analog-to-digital conversion. The processor module processes the received audio information and transmits the processed audio information to the data storage module.

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.

The present invention provides a fast common-mode detection circuit for a fully differential amplifier, comprising: a switch circuit, a comparator circuit, and an operational amplifier; the non-inverting input of the operational amplifier is connected to the differential output of the fully differential amplifier and the comparator circuit, the inverting input of the operational amplifier is connected to a first reference voltage, and the output of the operational amplifier is connected to the common-mode control terminal of the fully differential amplifier; the switch circuit is connected to the comparator circuit and the differential output of the fully differential amplifier. Through the above-described method, the present invention can quickly start the fully differential amplifier and reduce the stabilization time of the common-mode voltage.

The invention discloses a fully differential amplifier and electronic equipment, the fully differential amplifier comprises a first single-ended amplification link and a second single-ended amplification link, in the first single-ended amplification link, the grid electrode of a first MOS transistor is coupled with the input end of the first single-ended amplification link, and the drain electrode of the first MOS transistor is coupled with the source electrode of a second MOS transistor and the source electrode of a fifth MOS transistor; the drain electrode of the second MOS tube is coupled with the drain electrode of the third MOS tube, and a second bias voltage is input into the grid electrode of the second MOS tube; a source electrode of the third MOS transistor is coupled with a drain electrode of the fourth MOS transistor, a first bias voltage is input into a grid electrode of the third MOS transistor, and a drain electrode of the third MOS transistor is coupled with an output end of the first single-ended amplification link; the source electrode of the fourth MOS transistor inputs the power supply voltage, and the drain electrode of the fourth MOS transistor is coupled with the input end of the first single-ended amplification link; a second bias voltage is input into the grid electrode of the fifth MOS tube, and the drain electrode of the fifth MOS tube is coupled with the drain electrode of the sixth MOS tube and the input end of the first single-ended amplification link; and the grid electrode of the sixth MOS tube inputs the first bias voltage, and the source electrode of the sixth MOS tube is coupled with the drain electrode of the fourth MOS tube. According to the scheme, the noise generated by the first MOS transistor can be effectively reduced.

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 an ultra-wideband silicon-based phase shifter chip working at 0.2-2GHz, which is applied to the technical field of radio frequency microwave integrated circuits. The architecture of the chip consists of a fully differential amplifier, an orthogonal signal generator, a vector synthesis network and a digital-to-analog conversion control circuit. According to the chip, within the working frequency band of 0.2-2 GHz, the phase shifting precision can be 5.625 degrees, the phase shifting range can be 360 degrees, the phase RMS error is smaller than 2.7 degrees, the amplitude RMS error is smaller than 0.6 dB, the input and output return losses are smaller than 12 dB, the gain is larger than-0.5 dB, and the area of the chip is 0.88 mm < 2 >.

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 common-mode feedback circuit for a fully differential amplifier comprises first (MB), second (MTP), and third (MTN) transistors, each having a respective drain, source, gate, and back-gate terminals. The drain terminal of the first transistor (MB) and the gate terminals of the first, second, and third transistors (MB, MTP, MTN) are connected together at a bias current terminal. The drain terminals of the second and third transistors are connected together at a tail current terminal. The source terminals of the first, second, and third transistors are connected together. The back-gate terminal of the first transistor (MB) is arranged to receive a common-mode reference voltage input (VCM), the back-gate terminal of the second transistor (MTP) is arranged to receive a positive output voltage (VP) from the fully differential amplifier, and the back-gate terminal of the third transistor (MTN) is arranged to receive a negative output voltage (VN) from the fully differential amplifier.

The present invention relates to the technical field of integrated circuit design, and specifically discloses a low-noise programmable amplifier, comprising: a first fully differential amplifier, comprising two pairs of differential input terminals; a second fully differential amplifier, comprising a pair of differential input terminals, electrically connected to the first fully differential amplifier through an interstage chopper switch; a pair of input chopper switches, the input terminal of each input chopper switch is electrically connected to a differential input signal; a pair of output chopper switches, the output terminal of each output chopper switch is electrically connected to the output terminal of the second fully differential amplifier; an input capacitor network, located between a pair of input chopper switches and the two pairs of differential input terminals; a feedback capacitor network, located between a pair of output chopper switches and the two pairs of differential input terminals; and a plurality of zeroing switches, located between the input and output of the first fully differential amplifier. The two transconductance amplifiers inside the first fully differential amplifier of the present invention share the same current, and the overall transconductance is doubled compared to a single pair of differential inputs, thereby reducing the noise of the amplifier.

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 circuit for increasing common-mode transient immunity of a digital isolator for edge modulation and demodulation. The circuit comprises a transmitting end TX and a receiving end RX, the transmitting end TX comprises a negative common-mode voltage change rate detection circuit, the negative common-mode voltage change rate detection circuit is composed of a transistor MN11, a transistor MN12, a transistor MN13, a transistor MN14 and a fifth resistor R5, and the output ends of the transistor MN11 and the transistor MN12 are connected with the control ends of the transistor MN13 and the transistor MN14. The output end of the transistor MN13, the output end of the transistor MN14 and the fifth resistor R5 are connected with the grounding end GND1 of the transmitting end TX; the receiving end RX comprises a latch, a fully differential amplifier, an envelope comparator and a forward common-mode voltage change rate detection circuit; the forward common-mode voltage change rate detection circuit is composed of a transistor MN5, a transistor MN6, a transistor MN7, a transistor MN8 and a sixth resistor R6, the control ends of the transistor MN5 and the transistor MN6 are connected with the output end of the transmitting end TX, and the output ends of the transistor MN5 and the transistor MN6 are connected with the control ends of the transistor MN7 and the transistor MN8. And the output end of the transistor MN7, the output end of the transistor MN8 and the sixth resistor R6 are connected with the grounding end GND2 of the receiving end RX.

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.

The invention provides a signal conversion circuit, an analog-to-digital converter and electronic equipment. A fully differential amplifier in the signal conversion circuit is provided with a positive input end, a negative input end, a positive output end and a negative output end; the first capacitor is arranged between the positive input end and the negative output end or between the negative input end and the positive output end; the positive pole input end or the negative pole input end is used for receiving a single-ended signal, and the positive pole output end and the negative pole output end output differential signals under the condition that the single-ended signal is received. A rail-to-rail transmission fully differential amplifier is arranged, so that a relatively large common-mode input and output range is realized; in addition, the first capacitor in the application can process the input signal in an integral mode, so that high-frequency noise can be filtered.

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 relates to the technical field of differential amplifiers, and discloses a four-stage common-mode loop fully differential amplifier and an application method. The four-stage common-mode loop fully-differential amplifier comprises a two-stage fully-differential main amplifier for receiving a differential-mode signal, performing two-stage amplification on the differential-mode signal and then outputting a differential signal; the common-mode level sensing unit is used for capturing a common-mode level output by the two-stage fully-differential main amplifier; and the two-stage common-mode feedback amplifier receives the common-mode level and the common-mode reference signal at the same time, and is used for amplifying an error signal between the common-mode level and the common-mode reference signal and outputting the amplified error signal to a grid electrode of a current source load of the input stage of the two-stage fully differential main amplifier. According to the four-stage common-mode loop provided by the invention, the numerical value of the CMRR is remarkably increased, meanwhile, good isolation of the common-mode feedback loop and the differential loop is realized, and the gain of the main amplifier is not constrained.

The current detection circuit comprises a shunt resistor, a fully differential amplifier, a reference voltage output module and a subtracter, the fully differential amplifier performs primary amplification on voltages at two ends of the shunt resistor to obtain a first output voltage, and the first output voltage is used for outputting the first output voltage; the reference voltage output module is used for providing a reference voltage for the subtracter, the subtracter performs secondary amplification based on the first output voltage and the reference voltage to obtain a second output voltage, and the second output voltage is smaller than or equal to the first power supply voltage. Therefore, the reference voltage output module provides the reference voltage of which the numerical value is equal to one half of the first power supply voltage for the subtracter, so that the absolute value of the voltage at the two ends of the shunt resistor after twice amplification is smaller than or equal to one half of the first power supply voltage, and the measurement of the bidirectional current is realized; and the application scene of current detection is enlarged.

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 discloses a high and low frequency separation signal conditioning circuit for a peak power probe, and belongs to the technical field of testing. The circuit comprises a signal amplification circuit and a filter circuit. The problems of gain, bandwidth and noise are solved; higher common-mode rejection capability is obtained by using the fully differential amplifier, the symmetry of differential signals can be better ensured, and the signal output common-mode voltage can be conveniently adjusted; the bandwidth of the whole circuit is not limited by the first-stage operational amplifier, high bandwidth is obtained under high gain, and noise is as low as possible; common-mode interference can be better suppressed by adopting the fully differential amplifier, output common-mode voltage can be conveniently adjusted, and the driving capability is high.

A programmable gain amplifier provided in a semiconductor device includes a fully differential amplifier configured to amplify differential input voltages having an offset voltage. First and second correction voltages are input to a non-inverting input node and an inverting input node of the fully differential amplifier via first and second resistance elements, respectively.