20 results about "Open-loop gain" patented technology

The position-torque double closed-loop servo system parameter optimization control method provided by the invention is stable and rapid in dynamic response. On the basis that a position regulator is composed of first-order advanced feedback of a unit proportionality coefficient and regulation with proportion and integration as main components, a simplest expectation mathematical model of a closed-loop single-zero-point type 3 (a forward channel of the system has three integration links) control system is provided, and the maximum phase angle margin of the system is used as an optimization target. And deriving an analytic formula of system open-loop gain optimization setting, and further providing a position regulator parameter optimization setting control method which enables the position-torque double-closed-loop servo system to have low-overshoot, stable and rapid performance on step response. The method has important guiding significance on design of the position-torque double-closed-loop servo system requiring stable and rapid dynamic response, product development (including experimental equipment), on-site commissioning, debugging and the like, and meanwhile, the design theory of the motor position-torque double-closed-loop servo system is also perfected.

The application relates to a voltage follower-based addressable sensitive amplifier test circuit, which comprises: a sensitive amplifier array to be tested, the array comprising a plurality of sensitive amplifiers to be tested; an addressing circuit for providing an address signal to select a target sensitive amplifier; a switch selection circuit connected between the sensitive amplifier array to be tested and an external test node, controlled by the addressing circuit, for coupling the signal of the external test node to the selected sensitive amplifier; and a voltage follower module with an input end connected to the switch selection circuit, for transmitting the test voltage output by the switch selection circuit to the corresponding end of the selected sensitive amplifier. The application can realize efficient and accurate SA performance testing. The node voltage curve is only affected by the gain of the operational amplifier, and the design open-loop gain is above 60 dB, so that an error below 0.1% can be realized.

A supply voltage may be set using a local voltage regulator, such as a Digital Linear Voltage Regulators (DLVR). A DLVR may include a compensator, and the performance of the compensator may be affected by a dropout (DO) voltage. To improve the performance of a compensator, a number of compensator calculations may be pre-calculated to reduce the complexity of remaining real-time computations and enable compensator calculations to be completed within a single DLVR clock cycle. A DLVR may include a sense filter, and the DLVR transfer function (TF) may be modified using dynamic shaping of open loop gain and pole locations of a sense filter. The DO range associated with the DLVR TF may be changed according to a monitored DO(t) to reduce the sensitivity of a domain VMIN on dropout, which reduces power consumption, increases performance, and enables simplification of test flows.

The invention discloses an analog fast automatic gain control circuit for a transimpedance amplifier, which belongs to the field of optical communication transimpedance amplifiers, and adopts the technical scheme that a gain compensation unit is introduced into a feedback loop, the analog fast automatic gain control circuit comprises an operational amplifier A2, a resistor R2, an MOS (Metal Oxide Semiconductor) tube M1, an MOS tube M2, a resistor R1, a current source, an MOS tube M3, a resistor R3 and a capacitor C2, the equivalent resistance of the MOS tube M1 is reduced when the MOS tube M1 works in a linear region, and the equivalent resistance of the MOS tube M2 is reduced when the MOS tube M2 works in a linear region; under the synergistic effect of the source negative feedback circuit, the transconductance reduction of the controlled gain adjusting element is compensated, so that the open-loop gain stability of an automatic gain control loop is maintained; according to the scheme, the problem that the response time is inconsistent when the amplitude of the input signal is changed in the traditional analog automatic gain control is solved, the loop response time is consistent under different input amplitudes, the design upper limit of the circuit response speed is remarkably improved, meanwhile, the defect that the output amplitude is suddenly changed when a digital gain control scheme is switched is avoided, and the circuit reliability is improved. And the output stability and the high-speed performance are ensured.

A supply voltage may be set using a local voltage regulator, such as a Digital Linear Voltage Regulators (DLVR). A DLVR may include a compensator, and the performance of the compensator may be affected by a dropout (DO) voltage. To improve the performance of a compensator, a number of compensator calculations may be pre-calculated to reduce the complexity of remaining real-time computations and enable compensator calculations to be completed within a single DLVR clock cycle. A DLVR may include a sense filter, and the DLVR transfer function (TF) may be modified using dynamic shaping of open loop gain and pole locations of a sense filter. The DO range associated with the DLVR TF may be changed according to a monitored DO(t) to reduce the sensitivity of a domain VMIN on dropout, which reduces power consumption, increases performance, and enables simplification of test flows.

The invention discloses an addressable test circuit based on a voltage follower, and the circuit comprises an addressing circuit which is used for receiving an address signal and decoding according to the address signal; the switch circuit array comprises a VD signal switch array and a VG signal switch array; the VD signal switch array gates a corresponding switch unit according to a decoding result, and the gated switch unit couples a VD signal to a drain electrode of a selected to-be-tested unit in the to-be-tested unit array through a voltage follower; the VG signal switch array gates the corresponding switch unit according to the decoding result, and the gated switch unit couples the VG signal to the grid electrode of the selected to-be-tested unit in the to-be-tested unit array. According to the invention, the voltage drop of the VD signal in the transmission process can be greatly reduced, the voltage drop is only influenced by the gain of the operational amplifier, and the designed open-loop gain is more than 40dB, and the voltage drop below 1% can be realized.

The application discloses a kind of broadband solid-state power amplifier and pulse modulation method, belong to amplifier technical field, including amplifier unit, detection control unit, power module and power detection module, it solves the technical problem of improving the protection of GaN power device in high-power power amplifier, accurate control amplitude and improve the maintainability of modularity, the local grid negative voltage management of the present application is realized, power-on power-down timing control, drain pulse modulation and temperature monitoring, effectively avoid GaN chip damage due to power timing error or local overheating, significantly improve the reliability of the whole machine, support open-loop gain control and closed-loop automatic level control ALC two modes, effectively reduce the impact of pulse current on power bus, improve the flatness of output pulse top, ensure the consistency of each unit radio frequency phase and power supply timing, improve the synthesis efficiency, can be quickly positioned and replaced, greatly reduce the average repair time, improve the availability and usability of equipment.

A variable transimpedance amplifier may include first and second amplifiers. Each of the first and second amplifiers may include a transistor amplifier with a feedback resistor and a capacitor. The output node of the first amplifier may be an output node of the variable transimpedance amplifier. The output node of the second amplifier is not part of the output node of the variable transimpedance amplifier. The open loop gains of the transistor amplifiers may be variable, but the feedback resistor values can be fixed. The transimpedance may be determined by the feedback resistors and a scaling factor proportional to ratio of open loop gains. The transistor amplifiers may share an input transistor. The configuration can provide a high dynamic range of variable transimpedance that is stable over process and operating condition variations, minimize input capacitance loading and noise contribution to small input signals.

A distributed power management circuit is provided. The distributed power management circuit includes a main power management integrated circuit (PMIC) and a distributed PMIC separated from the main PMIC. The main PMIC is coupled to the distributed PMIC via a conductive path. Notably, a parasitic capacitance of the main PMIC can interact with a trace inductance of the conductive path to cause an equivalent notch that can degrade linearity performance of the distributed PMIC. In this regard, in embodiments disclosed herein, a deQ circuit is provided in the distributed power management circuit to reduce a quality factor (Q-factor) of the equivalent notch to thereby improve linearity performance of the distributed PMIC. Further, the deQ circuit can be so configured to increase an open loop gain of the distributed PMIC to help reduce current flow in the distributed PMIC to thereby improve overall energy efficiency of the distributed power management circuit.

The application provides a power semiconductor circuit and chip, the circuit comprises a chip, a channel is arranged in the chip, the circuit further comprises a flip voltage follower (FVF) used as a voltage buffer to ensure stable current output in the circuit, a compensation unit electrically connected to the two ends of the flip voltage follower (FVF) to ensure loop stability without output capacitor, and a non-inverting gain stage electrically connected to a power input end (VIN), a ground wire (GND) and the flip voltage follower (FVF) respectively to offset the channel length modulation effect during operation of the chip by increasing open-loop gain. The power semiconductor circuit and chip can effectively optimize the structure of the power semiconductor circuit, so that the circuit can meet the condition of no output capacitor and has the characteristics of high stability and high gain.

The application discloses a rail-to-rail input and output reference voltage buffer circuit for a SAR ADC. The circuit comprises a rail-to-rail input stage circuit, a gain bootstrap structure, a transconductance linearity loop structure and an AB class output stage circuit. The input stage adopts a double-folded common-gate structure to realize rail-to-rail input; the output stage adopts an AB class amplifier of a common-source transistor to realize rail-to-rail output; the transconductance linearity loop structure is used for stabilizing the static working point of the output stage and reducing crossover distortion; and the gain bootstrap structure is used for greatly improving open-loop gain. The application realizes high open-loop gain, low noise, high conversion speed and output short-circuit protection while ensuring rail-to-rail input and output swing, and is suitable for driving an analog-to-digital converter.

A microphone module includes: a microphone element outputting a microphone signal representing collected sound; an amplifier circuit outputting an amplified signal obtained by amplifying a difference between the microphone signal and a reference voltage; a high-pass filter outputting a high-band amplified signal obtained by filtering the amplified signal; a buffer circuit outputting an audio signal obtained by buffering the high-band amplified signal; a first low-pass filter outputting a low-pass bias voltage obtained by filtering the audio signal superimposed on a DC power supply, and a separation circuit outputting an internal bias voltage obtained by removing the influence of an external circuit from the low-pass bias voltage. The second low-pass filter outputs the reference voltage obtained by filtering the internal bias voltage. A circuit from the high-pass filter to the amplifier circuit is set such that an open loop gain is smaller than 0 dB.

The application provides a full-differential hysteresis comparator temperature compensation system and method with resistance as a load, and belongs to the field of hysteresis comparators.The application provides a full-differential hysteresis comparator temperature compensation system and method with resistance as a load, and provides a method for calculating the temperature coefficient of each end of a differential amplifier with a smaller load when the temperature coefficient of each type of unit resistance meets a linear constraint condition in the application.Meanwhile, the application provides a method for using two or more types of resistances through a series / parallel connection mode, adjusting the proportion of different types of unit resistances, and finally obtaining an ideal temperature coefficient of the load resistance.The application overcomes the defect that the resistance value of the load resistance of the hysteresis comparator structure follows the temperature change, solves the disadvantage that the open-loop gain of the hysteresis comparator changes with the temperature due to the problem, improves the signal processing rate of the comparator, improves the overall performance of the comparator, and makes the output result closer to the ideal effect.

The application discloses an analog fast automatic gain control circuit for a transimpedance amplifier, and belongs to the field of optical communication transimpedance amplifiers. The technical scheme introduces a gain compensation unit in a feedback loop, and comprises an operational amplifier A2, a resistor R2, a MOS tube M1, a MOS tube M2, a resistor R1, a current source, a MOS tube M3, a resistor R3, and a capacitor C2. When the MOS tube M1 works in a linear region, the equivalent resistance is reduced, and the source stage negative feedback circuit cooperates to compensate for the transconductance reduction of the controlled gain adjustment element, so that the open loop gain of the automatic gain control loop is maintained stable. The scheme solves the problem that the response time of the traditional analog automatic gain control is inconsistent when the input signal amplitude changes, realizes consistent loop response time under different input amplitudes, significantly improves the upper limit of the circuit response speed design, avoids the defect that the output amplitude suddenly changes when the digital gain control scheme is switched, and ensures the output stability and high-speed performance.

The application claims an operational amplifier with programmable compensation capacitor array, comprising a chopper module, a sleeve type gain enhancement operational amplifier and a programmable compensation capacitor array. The chopper module is used for periodic modulation of the input signal to suppress low frequency 1 / f noise and bias drift, thereby improving the input accuracy and linearity of the operational amplifier; the gain enhancement preamplifier provides high open loop gain through the sleeve type structure, while maintaining the trade-off between bandwidth and stability, and improving the small signal amplification capability; the programmable compensation capacitor array is composed of multiple switched capacitor units, which are selectively connected or disconnected by control signals, used to adjust the frequency response and phase margin of the operational amplifier, and realize the optimization of closed loop stability under different process, temperature and voltage conditions. The operational amplifier of the application not only maintains good stability at high gain, but also reduces input noise and drift, realizes high precision, low noise analog signal amplification.

A method for determining the stability of a multi-voltage-level DC distribution system containing multiple DC microgrids is disclosed. The method first confirms that the equivalent admittance of each microgrid subsystem has no right-half-plane poles based on the specific control mode of the interconnecting converter and the equivalent open-loop gain of each microgrid operating independently. Second, based on the two-port network matrix of the interconnecting converter, the multi-voltage-level DC distribution system containing multiple DC microgrids is simplified to a single-bus DC system containing only the distribution bus. The stability of the entire system is then determined using the equivalent impedance ratio. Under the premise that each unit within the system can operate stably independently, the stability of the entire system is guaranteed when the equivalent open-loop gain of each microgrid operating independently and the equivalent impedance ratio on the distribution bus side both satisfy the Nyquist criterion. This invention utilizes the equivalent open-loop gain of each DC microgrid operating independently and the equivalent impedance ratio of the system on the distribution bus side to analyze the stability of a multi-voltage-level DC distribution system containing multiple DC microgrids. It has good flexibility and applicability, and can provide a reliable theoretical basis for the design of multi-voltage-level DC distribution systems.

The invention discloses a novel high-precision low-dropout linear voltage regulator, and belongs to the technical field of analog integrated circuits, the novel high-precision low-dropout linear voltage regulator comprises an amplification stage, an output stage, a power stage, a pre-regulator and a frequency compensation technology, the amplification stage, the output stage and the power stage provide high open-loop gain, and the linear regulation rate and the load regulation rate are effectively improved; the pre-voltage stabilizer prevents power supply voltage ripples or noise from being transmitted to output voltage, so that the power supply rejection ratio is increased; the frequency compensation technology can ensure the stability of the amplifier to different capacitive loads under high open-loop gain. The high-precision reference driver has the advantage of high precision and is suitable for high-precision reference drivers.

This invention belongs to the field of integrated circuit technology, specifically relating to an open-loop residual amplifier circuit for pipelined successive approximation ADCs; it includes: a differential input circuit, a tail current circuit, a third PMOS transistor Mp3, a fourth PMOS transistor Mp4, a third NMOS transistor Mn3, and a fourth NMOS transistor Mn4; the third PMOS transistor Mp3, the fourth PMOS transistor Mp4, the third NMOS transistor Mn3, and the fourth NMOS transistor Mn4 are all connected to the differential input circuit; the tail current circuit is connected to the third NMOS transistor Mn3 and the fourth NMOS transistor Mn4; it does not require a very high open-loop gain, nor does it require a complex common-mode voltage detection circuit, resulting in a simple circuit structure and reduced circuit design difficulty; moreover, this invention is a dynamic circuit, which greatly reduces circuit power consumption and is suitable for low-power ADC design; this invention uses a push-pull input method, which greatly improves the input transconductance and has a large bandwidth, making it suitable for high-speed ADC design.

The invention discloses a low-noise high-gain operational amplifier circuit, which belongs to the technical field of analog integrated circuits and mainly comprises a main operational amplifier module, an auxiliary operational amplifier module, a biasing circuit module and a chopper circuit module. The main operational amplifier adopts a two-stage operational amplifier structure, the first stage is a folded cascode structure, and the second stage is a class AB structure; the auxiliary operational amplifier A1 and the auxiliary operational amplifier A2 are respectively composed of folding cascode input by a P tube and a N tube, so that the overall gain is improved; the bias circuit provides proper bias voltage for the main operational amplifier and the auxiliary operational amplifier; the chopper circuit significantly reduces the offset voltage and low-frequency noise of the operational amplifier. The amplifier has good stability and relatively high output swing, realizes extremely high direct-current open-loop gain, relatively low input reference noise and good frequency stability, and is suitable for being used in analog front-end programmable gain amplifier circuits and analog signal processing systems with extremely high requirements on signal precision and signal-to-noise ratio.

In order to provide a high voltage amplifier that operates stably at high speed, and a mass spectrometry device that comprises the same, the present invention is configured in the following manner.　This high voltage amplifier comprises: an error amplification circuit that outputs a control signal on the basis of an input signal and a feedback signal; a voltage conversion circuit that adjusts the potential of the control signal outputted from the error amplification circuit; a multistage transistor output circuit that, on the basis of the output of the voltage conversion circuit, outputs a high voltage for supply; a feedback circuit that, on the basis of the high voltage for supply, outputs the feedback signal to be inputted to the error amplification circuit; and an open loop gain control circuit that has a plurality of resistance elements and a capacitance element, said capacitance element being connected in parallel with at least one resistance element among the plurality of resistance elements and adding a pole and a zero point to the open loop gain, and generates a gain control signal for controlling the voltage conversion circuit on the basis of the high voltage for supply outputted from the multistage transistor output circuit. This mass spectrometer comprises said high voltage amplifier.