91 results about "Negative feedback amplifier" patented technology

A distance image sensor for removing the background light and improving the charge transfer efficiency in a device for measuring the distance to an object by measuring the time-of-flight of the light.In a distance image sensor for determining the signals of two charge storage nodes which depend on the delay time of the modulated light, a signal by the background light is received from the third charge storage node or the two charge storage nodes in a period when the modulated light does not exist, and is subtracted from the signal which depends on the delay time of the two charge storage nodes, so as to remove the influence of the background. Also by using a buried diode as a photo-detector, and using an MOS gate as gate means, the charge transfer efficiency improves. The charge transfer efficiency is also improved by using a negative feedback amplifier where a capacitor is disposed between the input and output.

A distance image sensor for removing the background light and improving the charge transfer efficiency in a device for measuring the distance to an object by measuring the time-of-flight of the light. In a distance image sensor for determining the signals of two charge storage nodes which depend on the delay time of the modulated light, a signal by the background light is received from the third charge storage node or the two charge storage nodes in a period when the modulated light does not exist, and is subtracted from the signal which depends on the delay time of the two charge storage nodes, so as to remove the influence of the background. Also by using a buried diode as a photo-detector, and using an MOS gate as gate means, the charge transfer efficiency improves. The charge transfer efficiency is also improved by using a negative feedback amplifier where a capacitor is disposed between the input and output.

An imaging device for sensing an image of an object includes a negative feedback amplifier, a substrate, a sense electrode, a couple electrode and an insulation protection layer. The sense and couple electrodes are disposed above the substrate. The insulation protection layer covers the sense and couple electrodes. The sense electrode and the object form a sense capacitor. The couple electrode and the object form a couple capacitor. A negative input terminal of the negative feedback amplifier is electrically connected to the sense electrode, and the couple electrode is electrically connected to a signal output terminal of the negative feedback amplifier and a signal input terminal of the imaging device.

A feedback controller comprises first and second feedback circuits. The first feedback circuit is connected between an input node and an output node and has an error node. The first feedback circuit comprising a feedback amplifier for comparing a feedback signal to a reference signal and providing an error signal, and a comparator for comparing the error signal to a second reference signal and providing an output signal. The second feedback circuit is connected between the input node and the error node and comprises a current source coupled to the error node and a controller coupled to the input node for controlling the current source in response to a value of the feedback signal being above or below a threshold value.

The variable gain amplifier includes a bias circuit (BC) 1, a matching circuit (MC) 2, a variable gain resistive feedback amplifier (FA) 3 and an output follower (EA) 4. The resistance values of the load resistance Rc and feedback resistance Rf are changed in cooperation. In a case of making the load resistance Rc a high resistance to set the low noise amplifier to a high gain, the feedback resistance Rf is also made a high resistance, the feedback time constant τfb(c1)≈2π·RfCbe / (1+gmRc) of the closed loop of the resistive negative feedback amplifier 3 becomes substantially constant, and then the amplifier has a gain small in frequency dependency over a wide bandwidth. In a case of making the load resistance Rc a low resistance to set the low noise amplifier to a low gain, the feedback resistance Rf is also made a low resistance. The feedback resistance Rf with the low resistance increases the negative feedback quantity, and thus the amplifier is set to a low gain. Also, the load resistance Rc is made a low resistance, and the feedback time constant τfb(c1) becomes substantially constant. The gain is not lowered further in a high frequency region.

A programmable gain amplifier with three stages uses fine steps, has a large gain range, and is monotonic. The first stage comprises several amplifiers, each including a resistive feedback loop. The feedback loop comprises a series of resistors, with each resistor acting as a tap. Since the number of resistors in the loop is unchanging, monotonicity and stability is guaranteed when resistance is increased using successive taps. A switch system connects two taps at a time to an interpolation stage. Each of these taps corresponds to a specific resistor level, and thus a gain level. The interpolation stage uses a plurality of current sources inside a feedback amplifier to control the interpolation, in order to provide fine gain steps.

A negative feedback amplifier has input portions for receiving input signals, adder circuits, a quadrature modulator for performing a quadrature modulation on outputs of the adder circuits, a first signal level variable control circuit for adjusting a level of an output signal from the quadrature modulator, an amplifier circuit for amplifying an output of the first signal level variable control circuit, a feedback circuit for negative feedbacking an output of the negative feedback circuit to the adder circuit, and a second control circuit for controlling an adjusting amount in the first signal level variable control circuit based on the output signal levels of the adder circuits so that the output signal levels of the adder circuits becomes predetermined values. The feedback circuit includes a first control circuit for controlling a signal level of the feedback circuit so that the output signal level of the amplifier circuit becomes a predetermined value.

The variable gain amplifier includes a bias circuit (BC) 1, a matching circuit (MC) 2, a variable gain resistive feedback amplifier (FA) 3 and an output follower (EA) 4. The resistance values of the load resistance Rc and feedback resistance Rf are changed in cooperation. In a case of making the load resistance Rc a high resistance to set the low noise amplifier to a high gain, the feedback resistance Rf is also made a high resistance, the feedback time constant τfb(c1)≈2π·RfCbe / (1+gmRc) of the closed loop of the resistive negative feedback amplifier 3 becomes substantially constant, and then the amplifier has a gain small in frequency dependency over a wide bandwidth. In a case of making the load resistance Rc a low resistance to set the low noise amplifier to a low gain, the feedback resistance Rf is also made a low resistance. The feedback resistance Rf with the low resistance increases the negative feedback quantity, and thus the amplifier is set to a low gain. Also, the load resistance Rc is made a low resistance, and the feedback time constant τfb(c1) becomes substantially constant. The gain is not lowered further in a high frequency region.

A negative feedback amplifier which alleviates reduction in band width and effectively protects an amplifier from electrostatic discharge (ESD). A node is provided at the midpoint of a feedback resistor connected between an output terminal and an input terminal of an amplifier. Each of ESD protective diodes are connected between the node and respective power terminals. ESD threshold voltage and band width vary in accordance with the resistance of a resistor between the input terminal and the node. Setting the resistance of the resistor at 10 to 100Ω makes it possible to secure the necessary ESD threshold voltage while hardly reducing band width.

The invention discloses an analog input circuit for engineering-machinery-dedicated controller. The analog input circuit comprises a voltage-current transformation circuit, which is a current series negative feedback amplifier circuit, and an analog voltage input circuit, which includes orderly connected a first RC filter circuit having an input thereof connected with a current output of said voltage-current transformation circuit, a noninverting amplifying circuit, and an isolating circuit having an output thereof connected with an A / D sampling port of a control unit. The analog resistor input circuit of the invention has the characteristics of strong anti-interference capability, high reliability, good compatibility, flexible applicability, and convenient operation, is also adaptable to wretched field environment and applied to the control circuit of engineering machinery equipment.

A negative feedback amplifier for a transmitter, in which a vector corrector outputs the corrected signals, an adder adds the feedback signals of the in-phase component and the quadrature component to the in-phase component and the quadrature component of the output of the vector corrector, respectively, a modulator performs a quadrature modulation with respect to the in-phase component and the quadrature component of the outputs from the adder, a power amplifier amplifies the output of the modulator, a demodulator performs a quadrature demodulation to a part of the output of the power amplifier and outputs the feedback signals of the in-phase component and the quadrature component, and the vector corrector performs a correcting operation of canceling an error of at least one of the phases and the amplitudes of the in-phase component and the quadrature component occurring in the demodulator.

The invention relates to a module parallel type high power direct current switch power device which comprises a plurality of direct current switch power modules which are parallel and a plurality of outer ring negative feedback modules of total output current and voltage after being parallel. One of the direct current switch power modules is internally provided with a current negative feedback inner ring control loop, and one of the outer ring negative feedback modules is internally provided with a total output current negative feedback outer loop and a total output voltage outer ring loop. The invention eliminates the master-slave installation operation of the prior master-slave installation method parallel power device, thereby causing the use to become simple, saving components and lowering the cost. At the same time, the device is added with the total output current negative feedback outer ring loop to cause the total output current after being parallel to also get negative feedback control, thereby greatly enhancing the output stability of the device.

An active resistor and its use in a negative feedback amplifier allow wide voltage swings on the input and output signals. One embodiment includes parallel pass-gate MOS transistors of opposite conductivity types connected between the input and output nodes. Bootstrapping transistors are connected between the gates of the pass-gate transistors and respective bias voltages. Coupling capacitors are connected between the gates and the output node. Additional coupling capacitors may be connected between the gates and the input node to make the resistor symmetric. In other embodiments, only one pass-gate transistor is used.

The photocurrent monitoring circuit (PMC) includes non-linear sampling circuit, negative feedback amplifier, sampling mirror image circuit, current mirror, and I / V switching circuit etc. The non-linear sampling circuit consists of transistor Q1 and resistance R2. The negative feedback amplifier is composed of amplifier A2 and field effect tube M8. The sampling mirror image circuit is composed of transistor Q2 and resistance R3. Current mirror, and I / V switching circuit include field effect tubes M4, M5, M6, M7 and resistance R4. Being able to monitor the input photocurrent in large dynamic range, PMC still keeps high precision. When PMC monitors the input photocurrent in large dynamic range, normal operation of main body of magnifier is not influenced.

The invention relates to an image sensing device which is used for sensing an image of an object. The image sensing device at least comprises a negative feedback amplifier, a substrate, a sensing electrode, a coupling electrode and an insulation protection layer, wherein the sensing electrode and the coupling electrode are arranged above the substrate; the insulation protection layer covers the sensing electrode and the coupling electrode; the sensing electrode and the object form a sensing capacitor; the coupling electrode and the object form a coupling capacitor; a negative input end of the negative feedback amplifier is electrically connected with the sensing electrode; and the coupling electrode is electrically connected to a signal output end of the negative feedback amplifier or a signal input end of the image sensing device.

A preamplifier includes a negative-feedback amplifier circuit that converts a current signal from a photodetector into a voltage signal; and a conversion-gain control circuit that simultaneously controls a resistance value of a feedback resistor portion of the negative-feedback amplifier circuit and a resistance value of a load resistor portion of the negative-feedback amplifier circuit, based on the voltage signal from the negative-feedback amplifier circuit. Each of the feedback resistor portion and the load resistor portion includes a fixed resistor element, a MOSFET element, and a diode-connected transistor, connected in parallel.

In a double-loop negative feedback low noise amplifier having double negative feedback paths by a feedback transformer and a feedback resistor added to a cascode amplifier comprising transistors and a resistor, a phase compensation circuit comprising a capacitor and a resistor is added between the output terminal of the double-loop negative feedback low noise amplifier and the input terminal of the cascode amplifier, i.e., the input terminal of the input transistor, and a phase compensation circuit comprising a capacitor and a resistor is added to the upper-stage transistor of the cascode amplifier, i.e., the input terminal of the upper-stage transistor. Those phase compensation circuits enable a low noise negative feedback amplifier which maintains a high feedback loop gain to a high frequency band, has a wider bandwidth than a conventional one, and has a high dynamic range.

In a double-loop negative feedback low noise amplifier having double negative feedback paths by a feedback transformer and a feedback resistor added to a cascode amplifier comprising transistors and a resistor, a phase compensation circuit comprising a capacitor and a resistor is added between the output terminal of the double-loop negative feedback low noise amplifier and the input terminal of the cascode amplifier, i.e., the input terminal of the input transistor, and a phase compensation circuit comprising a capacitor and a resistor is added to the upper-stage transistor of the cascode amplifier, i.e., the input terminal of the upper-stage transistor. Those phase compensation circuits enable a low noise negative feedback amplifier which maintains a high feedback loop gain to a high frequency band, has a wider bandwidth than a conventional one, and has a high dynamic range.

The present invention provides a semiconductor integrated circuit device equipped with a negative feedback amplifier circuit or a step-down circuit which realizes stabilization of an output voltage effectively in response to a variation in power supply voltage. A constant current source is used to cause a bias current for setting current consumption to flow in a differential amplifying MOSFET. A capacitor is provided between an external power supply voltage and a predetermined circuit node to thereby detect a reduction in the external power supply voltage. An operating current of the differential amplifying MOSFET is increased through the use of a current flowing in the capacitor due to such an external power variation, thereby executing the operation of stabilizing an output voltage corresponding to the reduction in the external power supply voltage.

The invention relates to an open loop amplifier with stable output common-mode voltage. The open loop amplifier comprises a main amplifier unit and an auxiliary amplifier unit. Compared with a conventional negative feedback amplifier with stable output common-mode voltage, the open loop amplifier has the beneficial effects that the differential output common-mode voltage of the main amplifier unit under an open loop structure is stable; the differential output end of the main amplifier unit does not adopt a common-mode feedback circuit, so that the output load is lowered, the working conversion speed of the amplifier is increased, and the frequency of an analog input signal can exceed 1GHz when the dynamic indicator SFDR (Spurious Free Dynamic Range) of the main amplifier unit exceeds 70dB. The circuit provided by the invention is applied to the field of ultrahigh-speed sampling / retaining circuits in low-voltage CMOS (Complementary Metal-Oxide-Semiconductor Transistor) process circuits with a high dynamic performance requirement.

A feedback architecture for ionizers that allows simultaneous adjustment of positive and negative ionizer power supplies. Balance and swing data are fed back to the ionizer through an intermediate module, which permits an extra level of signal processing. Swing information is returned to both power supplies in negative feedback mode. If swing is too high, both power supplies lower output. Balance is fed back in both negative and positive feedback mode. This architecture is compatible with multiple sensors and multiple ionizers.

The amplifier comprises an inverting negative feedback amplifier circuit using an operational amplifier, a comparator for comparing the potential of the negative phase input terminal of the operational amplifier with the reference potential Vref of the comparator, and a low-pass filter. The imaginary short state of the operational amplifier is lost when clipping occurs on the output signal. It is thus possible to detect clipping by monitoring the potential of the negative phase input terminal.

A feedback amplifier having an improved feedback network including two cross coupled switches that isolate the amplifier from extraneous undesired electrical signals present in a system or network when the amplifier is turned off (i.e., in an off-state). The cross coupled switches interconnect two feedback paths of a feedback network to enable out-of-phase differential signals to be summed and effectively canceled. Further, the feedback amplifier provides on-stage advantages to enable different amplifier characteristics and parameter to be selectively engaged by turning on or turning off certain feedback networks.

A method for double sampling loop negative feedback comprising: obtaining a low-frequency feedback signal from the output of the amplifier; obtaining a high-frequency feedback signal from part of the amplifier of which high-frequency phase shift is low, wherein two-ways sampling signals have the same amplifying phase; combining the two-ways sampling signals together using a series capacitor-inductor double signal combining circuit to form one signal, the signal having low phase shift at both high and low-frequency and being used for negative loop feedback. The invention also provides a double negative feedback amplifier using the method.

The invention provides a low-delay temperature compensation biasing circuit for time division duplexing mode, comprising: switch tube; potentiometer, one end connected with output end of the switch tube, voltage dividing output end passing through series-connected resistor and filter decoupling circuit and acting as output bias voltage, and another end earthed through temperature compensation diodes; the temperature compensation diodes comprise series-connected first and second diodes; the input voltage is inputted into a voltage stabilizing tube and then outputted to the switch tube, the earth end of the voltage stabilizing tube is connected in between the first and second diodes; a negative feedback amplifier is connected in series between the series-connected resistor and filter decoupling circuit. And it compensates bias voltage of the amplifier, makes the static current of the amplifier keep constant and electric performance not influenced.

The invention discloses a high precision portable electrochemical detection terminal. In the prior art, the conventional electrochemical detector has the disadvantages of complicated structure, bad interference resistant performance, bade stability, and low detection precision, and the provided detection terminal solves the problems mentioned above. The detection terminal is characterized by comprising a forward voltage follower circuit, a RE electrode and CE electrode based on the forward voltage follower circuit, a current / voltage conversion circuit, a WE electrode based on the current / voltage conversion circuit, and a three-circle opposite vertex intersected negative feedback amplifier, which is connected to the current / voltage conversion circuit. The provided detection terminal has the advantages of simple circuit, good circuit stability, strong interference resistant property, low energy consumption, and high testing precision, and thus is suitable for promotion and application.

To satisfy a specified frequency band over a wide range by regulating the phase characteristics of an input signal using an operational amplifier arranged differently from a feedback amplifier at an error amplifier section, and to prevent oscillation while having a sufficient phase margin in the frequency characteristics of an open loop. An error amplifier section 32 for amplifying the input signal of the entire circuit depending on a feedback signal from an output current voltage converting section 34 for voltage converting the output current of the entire circuit is provided with a voltage control / current output type operational amplifier 6 having a transfer conductance gm and outputs a current of an amplified input signal. The operational amplifier 6 has a constant current source and the characteristics of a differential amplification circuit based on the transfer conductance gm. Consequently, a phase regulation circuit corresponding to the operational amplifier 6 comprises a resistor R31 and a capacitor C31 being connected in series between the output terminal of the operational amplifier 6 and the earth potential.

The present invention provides a semiconductor integrated circuit device equipped with a negative feedback amplifier circuit or a step-down circuit which realizes stabilization of an output voltage effectively in response to a variation in power supply voltage. A constant current source is used to cause a bias current for setting current consumption to flow in a differential amplifying MOSFET. A capacitor is provided between an external power supply voltage and a predetermined circuit node to thereby detect a reduction in the external power supply voltage. An operating current of the differential amplifying MOSFET is increased through the use of a current flowing in the capacitor due to such an external power variation, thereby executing the operation of stabilizing an output voltage corresponding to the reduction in the external power supply voltage.

A feedback amplifier having an improved feedback network including two cross coupled switches that isolate the amplifier from extraneous undesired electrical signals present in a system or network when the amplifier is turned off (i.e., in an off-state). The cross coupled switches interconnect two feedback paths of a feedback network to enable out-of-phase differential signals to be summed and effectively canceled. Further, the feedback amplifier provides on-stage advantages to enable different amplifier characteristics and parameter to be selectively engaged by turning on or turning off certain feedback networks.