262 results about "Differential amplifier" patented technology

The ultralow frequency sensor comprises a vibration detection unit, a power supply voltage stabilization unit and a signal conditioning unit, the power supply voltage stabilization unit is provided with a low dropout linear voltage regulator U20, a voltage converter U19 and a negative voltage regulator U21, and the low dropout linear voltage regulator U20 stabilizes an external power supply as a positive power supply VCC; the voltage converter U19 is used for converting positive voltage of an external power supply into negative voltage and outputting stable negative power supply VEE through the negative voltage stabilizer; the positive power supply VCC and the negative power supply VEE supply power to the signal conditioning unit; the signal conditioning unit comprises a high common mode rejection differential amplifier, a differential-to-single-ended amplifier, a band-pass filter and a differential output driver, a differential signal output by the vibration detection unit sequentially passes through the high common mode rejection differential amplifier, the differential-to-single-ended amplifier, the band-pass filter and the differential output driver, and then a differential voltage signal is output; the method has the advantages of high stability and reliability and the like.

Amplifiers incorporating equalizer and bias offset correction circuits are described. An example amplifier circuit with equalizer and bias offset correction includes an amplifier with an input, an equalizer circuit coupled to the input of the amplifier, and a bias offset correction circuit coupled to the input of the amplifier. The bias offset correction circuit is configured to adjust a bias potential at the input of the amplifier. In one example, the amplifier is a differential amplifier with differential inputs, the equalizer circuit is coupled to the differential inputs of the amplifier and is configured to adjustably modify a gain of the amplifier over frequency, and the bias offset correction circuit is coupled to the differential inputs of the amplifier and is configured to compensate for modifications to bias potentials at the differential inputs of the amplifier due to operation of the equalizer circuit.

The invention relates to the technical field of photoelectric detection, and provides a single-photon counter circuit for weak light detection based on a photomultiplier, and the single-photon counter comprises a photoelectric conversion circuit, a differential amplification circuit, a threshold comparison circuit and a signal shaping circuit. The photoelectric conversion circuit is composed of a photomultiplier, a high-voltage power supply circuit and a voltage division circuit, detects weak light signals and outputs two paths of current signals through photoelectric conversion. The differential amplification circuit carries out differential amplification on the two current signals through a differential amplifier. The threshold comparison circuit compares two input signals, filters out signals with the amplitude lower than 1 / 2 of a set threshold, and outputs a single-path effective signal. And the signal shaping circuit shapes the effective signal and finally outputs the effective signal in a TTL pulse mode. According to the single photon counter circuit for weak light detection, the background dark counting rate is low, the sensitivity is high, and the counting unit module specially used for digital pulse statistics is connected behind the single photon counter circuit for counting single photons.

A dynamic vision sensor (DVS) system includes a pixel array composed of a plurality of pixels; a multi-channel differential amplifier composed of a plurality of differential amplifiers coupled to respectively receive plural pairs of pixel signals from one or more frames read out of the pixel array, thereby generating a plurality of difference signals respectively; a multi-channel comparator composed of a plurality of comparators configured to respectively compare the difference signals with a predetermined threshold, thereby generating a plurality of flags respectively; and an event detection circuit that generates an event signal according to the flags.

An electronic circuit comprising a first transistor coupled between a voltage supply and a first node, a second transistor coupled between the voltage supply and a second node, and a differential amplifier comprising first and second input terminals and an output terminal. The differential amplifier is coupled to an input terminal of the first transistor and to an input terminal of the second transistor. The first node is coupled to the first input terminal of the differential amplifier. The second node is coupled to the second input terminal of the differential amplifier.

This invention belongs to the field of wireless communication technology. It provides a differential amplifier system and a method for improving common-mode stability. The invention uses a large decoupling capacitor C1 at the transformer center tap to provide AC ground, and a common-mode resistor R1 to improve the circuit's common-mode stability. Since the common-mode resistor R1 is not in the differential signal loop path, the use of common-mode resistor technology does not affect differential-mode performance. Because the required common-mode resistor value is small, this design occupies a small layout area. This invention solves the problem of low common-mode stability in differential amplifiers.

Embodiments include herein are directed towards a circuit having a core bandgap reference circuit including a first transistor, a second transistor, and a differential amplifier. The circuit may further include a cascoded bandgap reference circuit in electrical communication with the core bandgap reference circuit, wherein the cascoded bandgap reference circuit includes a first supply noise path that includes a plurality of transistors that are electrically connected and a flipped voltage follower configuration that reduces an impedance at a transistor associated with a second supply noise path.

The techniques described herein relate to a circuit including an operational amplifier that includes a differential amplifier, a capacitor, and an output stage. The differential amplifier includes a first input and a second input. The output stage is configured to generate an output voltage. The circuit includes a slew-rate boost circuitry connected to the operational amplifier. The slew-rate boost circuitry is configured to detect a voltage differential between the first input and the second input and apply, at an output of the differential amplifier, a boost current to charge the capacitor during a period of time in which the output voltage increases or decreases to a target voltage level.

The application discloses a kind of control circuit and method of server standby power supply, including main power drive unit, analog PI regulator, current sampling conditioning circuit and OringFET tube;Main power MOS tube realizes main loop on-off control, and triode is used to change the gate voltage of main power MOS tube to control its conduction, cut-off;Analog PI regulator is composed of reference source and operational amplifier, reference source provides accurate reference voltage, and operational amplifier compares and adjusts current detection signal with reference voltage, dynamically corrects the control level signal of output, and then controls the on-off of main power MOS tube through driving circuit;Current sampling conditioning circuit includes sampling resistance and differential amplifier, and real-time acquisition main loop current is converted into identifiable voltage signal, to provide accurate data support for analog PI regulator.The application is applied when server is in shutdown state, and can be remotely executed by network to start, restart, install operating system or monitor hardware health state and the like operation.

The invention discloses a tumor detection device and method based on a diamond quantum sensor, and belongs to the technical field of biomedical detection. The device comprises an optical fiber laser, an optical fiber beam splitter, an optical fiber attenuator, an optical fiber circulator, an optical filter, two photoelectric detectors, a differential amplifier, an electronic filter, a computer, a signal generator, two microwave antennas and an optical fiber probe. The optical fiber probe comprises an optical fiber packaged in a plastic shell, a diamond quantum sensor which is fixed at the tail end of the optical fiber and comprises an NV color center, and a first microwave antenna integrated beside the optical fiber. The laser excites the diamond to generate fluorescence, meanwhile, the signal generator drives the two microwave antennas to apply a microwave field, and the dielectric property of the sample to be detected modulates the fluorescence intensity of the diamond by influencing the microwave field. Laser noise is eliminated through a differential amplification and filtering technology, and fluorescence signal change is analyzed by a computer, so that dielectric constant distribution of a sample is reconstructed, and non-invasive and high-sensitivity detection of tumors is realized.

The present application relates to the technical fields of dynamic reverse bias test, and relates to a circuit and a method for detecting dynamic leakage current in dynamic reverse bias of silicon carbide power devices, the circuit comprises a circuit for detecting dynamic leakage current in dynamic reverse bias of silicon carbide power devices, including a gate resistor, a half-bridge topology circuit, a Schottky barrier diode, a differential amplifier and a direct current power supply, the half-bridge topology circuit comprises an upper bridge auxiliary measurement silicon carbide power device, a lower bridge measured sample and a lower bridge sampling resistor, the gate of the auxiliary measurement silicon carbide power device and the gate of the measured sample are respectively connected with a gate drive input signal through the gate resistor; a plurality of Schottky barrier diodes are connected in parallel with the lower bridge sampling resistor to form an active low-pass filter, the non-inverting input and the inverting input of the differential amplifier are respectively connected with the anode and the cathode of the Schottky barrier diode; the present application can effectively filter out current spikes, solve the problem of related high dV / dt current spikes, and ensure the high precision of the leakage current monitoring signal.

Disclosed is a semiconductor integrated circuit device including: a switching transistor; a terminal to receive a control signal from outside; and a control circuit that controls the switching transistor based on the control signal. The control circuit includes: a reference voltage source that generates a reference voltage from the DC voltage; a differential amplifier to receive the reference voltage and a voltage of the voltage output terminal, and output a voltage applied to a control terminal of the switching transistor; and a logic circuit that generates a signal to control an operation state of the differential amplifier based on the control signal. According to an output signal of the logic circuit, the differential amplifier controls the switching transistor to be on in response to the control signal being a first logic level, and to be off in response to the control signal being a second logic level.

The invention discloses a crawler-type pipeline detection device and method based on a magnetic eddy current principle, and belongs to the technical field of pipeline defect detection.The crawler-type pipeline detection device comprises a crawler-type moving vehicle, a detection module, a detection module and a control module, and the crawler-type moving vehicle is provided with a power source and electrically connected with the power source; the camera is arranged at the upper end of the crawler-type mobile vehicle; the camera is electrically connected with the power supply and the control module; the magnetic eddy current probe is arranged at the front end of the advancing direction of the crawler-type mobile vehicle and is electrically connected with the power supply and the control module; the magnetic eddy current probe comprises three detection coils, one detection coil is a central excitation coil, and the other two detection coils are differential receiving coils; the center excitation coil is connected to the output end of the signal generator through a signal excitation line, the two differential receiving coils are connected to the input end of the differential amplifier through signal receiving lines, and the whole circuit is connected to the control module. According to the invention, real-time image transmission, dotting positioning, video monitoring, data acquisition, small crack detection and effective early warning can be carried out, and various defects of manual detection are avoided.

The oscillation circuit 1 comprises: an oscillator X1; a first capacitance CF having one end connected to the oscillator X1; a second capacitance CO having one end connected to the other end of the first capacitance CF; an output terminal Vo connected to a connection point N2 of the first capacitance CF and the second capacitance CO; an amplifier circuit A1 connected between a node between the oscillator X1 and the first capacitance CF and a connection point N2 of the first capacitance CF and the second capacitance CO to form an oscillation loop together with the first capacitance CF; a differential amplifier circuit A2 arranged on the oscillation loop; and a feedback path 3 configured to feed a part of an output on the output terminal Vo to the differential amplifier circuit A2.

In described examples, a low dropout voltage regulator includes an input voltage terminal, a resistive element, first and second transistors, an output terminal, a differential amplifier, and first and second saturation prevention circuits. The resistive element is coupled between the input voltage terminal and a gate of the first transistor. The output terminal is coupled to the drain of the first transistor and the source of the second transistor. A first input of the differential amplifier receives a reference voltage, and a second input is coupled to the output terminal. The first saturation prevention circuit provides a first clamp current to the differential amplifier output if the gate-source voltage of the first transistor is less than a first threshold voltage. The second saturation prevention circuit provides a second clamp current to the differential amplifier output if the gate-source voltage of the second transistor is greater than a second threshold voltage.

Oscillator device (10) comprising: - a ring oscillator circuit (20) with at least one delay stage (50), wherein an output of a last delay stage is fed back to an input of a first delay stage, wherein each of the delay stages (50) is configured to receive a charging current and provide a delay which depends on the charging current, and wherein at least one of the delay stages (50) comprises a metal-oxide-semiconductor field-effect transistor; - a bias circuit (30) comprising an output terminal coupled to an input terminal of the ring oscillator circuit (20), wherein the bias circuit (30) is configured to receive a temperature-independent reference voltage (Vref) and comprises a current source with a primary n-channel metal-oxide-semiconductor NMOS transistor (M0), wherein the current source is configured toto supply a control current (Iptat) to the ring oscillator circuit (20) which is proportional to a difference between the temperature-independent reference voltage (Vref) and a gate-source voltage (Vgs) of the primary NMOS transistor (M0), wherein the gate-source voltage (Vgs) of the primary NMOS transistor (M0) includes a negative temperature coefficient, wherein the bias circuit (30) further comprises: - a differential amplifier (A) configured to compare the temperature-independent reference voltage (Vref) with a measurement voltage, - a feedback transistor (M3) with a gate-drain path of the feedback transistor (M3) arranged in a negative feedback loop of the differential amplifier (A), - a resistor network (R),wherein a drain of the feedback transistor (M3) is coupled to a first terminal (1) of the resistor network (R) and a drain of the primary NMOS transistor (M0) is coupled to a second terminal (2) of the resistor network (R) and the measurement voltage is tapped at the first terminal (1) of the resistor network (R), and a capacitor coupled to an output of the differential amplifier (A) and the first terminal (1).

Some embodiments of this application provide a voltage detector including an input gate configured to receive an input voltage and a reference voltage, and an input device and a protection device, each having a low threshold voltage. The voltage detector also includes a current source, a load connected to a first diode, a load connected to a second diode, a first pre-charge device and a second pre-charge device, and an input differential amplifier composed of devices whose threshold voltage is significantly higher than the low threshold voltage. This voltage detector is capable of operating at a supply voltage approximately twice the upper limit of the operating voltage range of the input device. The voltage detector in the "on" state is configured to pull up or pull down the output voltage at the output of the differential amplifier when the input voltage is higher or lower than the reference voltage, respectively. This application also provides a voltage regulator including the above-described voltage detector.

An example apparatus includes: a differential amplifier circuit having a pair of first and second input transistors, the first input transistor having a control electrode supplied with an input signal, the second input transistor having a control electrode supplied with a reference potential; and a replica circuit having first, second, and third replica transistors coupled in series. The differential amplifier circuit is configured to be activated responsive to a first timing signal. The first and second input transistors and the first and second replica transistors have a first conductivity type. The third replica transistor has a second conductivity type opposite. Each of the first and third replica transistors has a control electrode supplied with the second timing signal. The second replica transistor has a control electrode supplied with the reference potential.

The present disclosure relates to a semiconductor device and a cell potential measuring device capable of improving measurement accuracy of a potential of a solution. A semiconductor device includes a read electrode that reads a potential of a solution, a differential amplifier, a first capacitor connected in series in a loop feeding back an output of the differential amplifier to a second input different from a first input from the read electrode, a resistance element connected in parallel with the first capacitor, and a second capacitor connected between a reference electrode indicating a reference potential and the second input. The present disclosure can be applied to, for example, a cell potential measuring device.

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.

This application relates to the field of microphone technology, and discloses a differential amplifier circuit and a desktop microphone. The circuit is used to amplify and process the differential audio signal of the desktop microphone. Its features include an input signal receiving and DC bias module, a differential transistor amplifier module, a fully differential operational amplifier module, a cross-feedback network module, a power supply and reference voltage module, and an output signal processing module connected in sequence. A common-mode negative feedback network for suppressing common-mode signals is provided between the emitters of the two corresponding symmetrical amplification paths of the differential transistor amplifier module. A cross-feedback network module is provided between the differential output terminal and the differential input terminal of the fully differential operational amplifier module to form an AC differential negative feedback loop. The power supply and reference voltage module includes at least two reference voltage units, which respectively provide DC bias for the differential transistor amplifier module and set the output common-mode level for the fully differential operational amplifier module.

The present disclosure relates to apparatuses and methods for limiting current. An apparatus for limiting current includes a differential amplifier configured to equalize a voltage across a power transistor and a sense transistor and a regulation circuit of an output current of the apparatus for limiting the current. The regulation circuit includes a transconductance amplifier configured to limit the output current when an output potential of the differential amplifier is higher than or equal to a reference potential proportional to a reference current, the value of the reference current being equal to I LIMIT / (N.M), where I LIMIT corresponds to a current limit value, N corresponds to a width-to-length ratio between the power transistor and the sense transistor, and M corresponds to a width-to-length ratio between transistors of a current mirror coupled to the sense transistor.

The invention discloses a CMOS (Complementary Metal Oxide Semiconductor) broadband low-noise amplifier with compact size and low power consumption. The CMOS broadband low-noise amplifier comprises a first matching transformer, a first-stage differential amplifier, an intermediate matching transformer, an intermediate resonant network, a second-stage differential amplifier and a second matching transformer, the first matching transformer is used for receiving a radio frequency input signal and realizing impedance matching; the first-stage differential amplifier is used for performing first-stage amplification on the radio frequency input signal; the intermediate matching transformer is used for transmitting the radio frequency signal after the first-stage amplification; the intermediate resonance network is used for carrying out resonance processing on the amplified radio frequency signal; the second-stage differential amplifier is used for performing second-stage amplification on the radio frequency signal after resonance processing; and the second matching transformer is used for realizing output impedance matching and outputting the radio frequency signal after second-stage amplification. According to the differential low-noise amplifier, high-gain broadband can be realized, and meanwhile, the area is compact and the power consumption is low.

The invention provides a receiver front-end circuit, a control chip and electronic equipment, and belongs to the technical field of artificial intelligence chips, and the receiver front-end circuit comprises a first module, a second module, a reference voltage generation module, a common-mode voltage generation module and a state machine; the first module comprises a differential amplifier, a common-mode feedback circuit, a first resistor, a second resistor, a first switch tube, a second switch tube and a current mirror; the positive phase output end of the differential amplifier is connected with the control end of the first switching tube; the negative phase output end of the differential amplifier is connected with the control end of the second switching tube; the normal phase input end of the second comparator is connected with the first end of the second switch tube through the first RC filter; the state machine is connected with the common-mode voltage generation module and used for controlling the register to generate a control code according to the comparison result of the second comparator, and the control code is used for controlling the common-mode voltage generated by the common-mode voltage generation module. According to the receiver front-end circuit provided by the invention, duty ratio correction is fused at the RX front end, and an additional DCC circuit does not need to be introduced.

A differential sensing system for sensing a current through a circuit element of a circuit, the differential sensing system comprising: a first current sense path having an input for coupling to a first node of the circuit element, the first current sense path comprising a first plurality of replica devices; a second current sense path having an input for coupling to a second node of the circuit element, the second current sense path comprising a second plurality of replica devices, wherein the second plurality is equal to the first plurality; a first cross-coupling switch operable to couple the input of the first current sense path to the second plurality of replica devices; a second cross-coupling switch operable to couple the input of the second current sense path to the first plurality of replica devices; differential amplifier circuitry having first and second inputs, wherein the differential amplifier circuitry is configured to output a differential replica current pair indicative of the current through the circuit element; and a controller, wherein the differential sensing system is operable in a chopping mode to perform a chopping operation in which: the first cross-coupling switch and a replica device of the first current sense path are controlled by the controller to couple the first input of the differential amplifier circuitry to the input of the first current sense path in a first phase of a chopping operation and to the input of the second current sense path in a subsequent phase of the chopping operation; and the second cross-coupling switch and a replica device of the second current sense path are controlled by the controller to couple the second input of the differential amplifier circuitry to the input of the second current sense path in the first phase of the chopping operation and to the input of the first current sense path in the subsequent phase of the chopping operation.

The invention provides a current sampling circuit with a switchable range. The current sampling circuit comprises a sampling circuit, a voltage following circuit, a differential amplification circuit and a range switching circuit. Automatic sampling is realized through a circuit in a self-sampling mode, and meanwhile, the resistance of an amplifying circuit is automatically switched for different ranges by utilizing a range-switchable circuit, so that the sampling requirements of different ranges are met.

The utility model provides a high-bandwidth Hall current sensor chip and a circuit structure thereof. The circuit structure comprises a first Hall element and a second Hall element which are used for sensing a detection current and generating a differential voltage signal; the three-stage low-frequency amplification chopping module is used for carrying out high-precision amplification and ripple and offset elimination on the differential signals and comprises a high-bandwidth fully-differential amplifier input stage and a high-bandwidth fully-differential amplifier output stage, and the high-bandwidth fully-differential amplifier input stage comprises two operational amplifiers; the comparator is used for comparing the amplified signal output by the three-stage low-frequency amplifying and chopping module with a reference signal to generate a final output signal; and the programmer is used for adjusting the output sensitivity and / or the static output voltage. According to the high-bandwidth current sensor, a dual-channel signal transmission structure and a three-stage low-frequency amplification chopping module are adopted, high bandwidth can be achieved, the ever-increasing frequency requirement is met, the compromise between residual offset and residual ripple amplitude is solved, and quick response of the high-bandwidth current sensor can be achieved.

The invention discloses an isolation monitoring device for a grounding conductor, and the device comprises an isolation part which is made of insulating plastic and is in a semicircular shape; the fixing device is used for fixing the separator in the deep pit; the resistivity monitoring sensor is arranged on the isolation piece, and the resistivity monitoring sensor comprises a built-in measuring electrode pair and at least two pairs of high-conductivity material electrodes, and the built-in measuring electrode pair and the at least two pairs of high-conductivity material electrodes are kept in electric contact with the surface of the grounding conductor at a constant interval; the miniaturized intelligent signal processing and communication unit integrates a microprocessor, a constant current source, a differential amplifier and an analog-to-digital converter and is used for controlling a measurement time sequence and calculating resistivity; the integrated wireless communication and remote power supply module supports a LoRaWAN or NB-IoT protocol, and adopts a lithium thionyl chloride battery and a micro energy collector for hybrid power supply. According to the invention, the fixing, isolating and state monitoring functions of the grounding conductor are integrated, the structure is compact, and the construction and maintenance process is simplified.

An overcurrent protection integrated circuit includes: a current input including a first resistor receiving an input current; a current sense amplifier circuitry including a differential amplifier, a switching element, a second resistor, and a current mirror circuit; and an overcurrent determiner including a third resistor and an overcurrent protection comparator. The current sense amplifier circuitry controls, through the differential amplifier, a voltage of the second resistor to be equal to a voltage of the first resistor, and sends out, from the switching element toward the current mirror circuit, a current decreased to a predetermined ratio relative to the input current. The overcurrent determiner compares a voltage of the third resistor and a voltage of a direct-current power supply, and outputs a signal when the voltage of the third resistor exceeds the voltage of the direct-current power supply. The first resistor and the second resistor include the same metal material.

The application discloses a low-dropout voltage regulator. The low-dropout voltage regulator comprises a differential amplifier circuit, a self-stabilized second-stage amplifier circuit, an output circuit and a frequency compensation circuit. The differential amplifier circuit is electrically connected with the self-stabilized second-stage amplifier circuit. The self-stabilized second-stage amplifier circuit is electrically connected with the output circuit. The frequency compensation circuit is arranged between an output end of the self-stabilized second-stage amplifier circuit, a second end of an output switch component of the output circuit and a third end of the output switch component of the output circuit.