32results about "DC-isolation amplifier" patented technology

Certain aspects of the present disclosure provide techniques for pre-distortion training feedback via inductive coupling. An example apparatus includes a receive path; a transmit path comprising an amplifier having a first output that is inductively coupled to the receive path; a memory; and a processor coupled to the memory. The processor is configured to cause the apparatus to obtain a first signal, based on a second signal output by the amplifier, via the receive path being inductively coupled to the first output of the amplifier; determine a parameter for pre-distortion associated with the amplifier based at least in part on the first signal; pre-distort a third signal based at least in part on the parameter; amplify the pre-distorted third signal via the amplifier; and transmit the amplified third signal.

The present disclosure relates to chopper amplifier circuits featuring inherent chopper ripple suppression. A chopper amplifier circuit includes a modulator circuit tuned to a chopper frequency, and configured, in accordance with the chopper frequency, to convert a voltage into an AC voltage; an amplifier circuit having inverting and non-inverting inputs for the AC voltage, and having inverting and non-inverting outputs for an amplified AC voltage; a demodulator circuit tuned to the chopper frequency, and configured to convert the amplified AC voltage into an amplified DC voltage, the inverting output being coupled, via a first capacitance in a first signal path, to a first input of the demodulator circuit, the non-inverting output being coupled, via a second capacitance in a second signal path, to a second input of the demodulator circuit; and a discharge resistor circuit coupled on an output side of both capacitances between the first and second signal paths.

Chopper amplifiers with tracking of multiple input offsets are disclosed herein. In certain embodiments, a chopper amplifier includes chopper amplifier circuitry including an input chopping circuit, an amplification circuit, and an output chopping circuit electrically connected along a signal path. The amplification circuit includes two or more pairs of input transistors, from which a control circuit chooses a selected pair of input transistors to amplify an input signal. The chopper amplifier further incudes an offset correction circuit that senses the signal path to generate an input offset compensation signal for the amplification circuit. Furthermore, the offset correction circuit separately tracks an input offset of each of the two or more pairs of input transistors.

Embodiments of an interface circuit, a MicroElectroMechanical system (MEMS) interface circuit, and a method for operating an interface circuit are disclosed. In an embodiment, an interface circuit includes an input chopper circuit configured to apply an excitation voltage to a transducer by pre-charging the transducer with bias voltages in alternating sensing cycles to generate a transducer difference charge, an input common-mode control circuit configured to generate a common-mode voltage in response to the applied excitation voltage, and a capacitance-to-voltage (C / V) and output chopper circuit configured to, in response to the common-mode voltage, integrate transducer difference charge on capacitors to produce an output voltage.

To provide a circuit structure capable of improving reliability of a power line communication.SOLUTION: A circuit structure includes a power line, and an electric energy wave and a network signal are transmitted onto the power line. The circuit structure contains: a first isolator 201; and a first coupler 202. The first isolator is arranged to each power consumption end E of the circuit structure or an inlet of a part of the power consumption end, separates the power line into the power consumption end and a transmission end T, and is used for removing the network signal so that the electric energy wave is entered into the power consumption end. The first coupler is used for generating a first coupling path P1, the network signal does not pass the first isolator by the first coupling path, and enters into the transmission end via the first coupling path.SELECTED DRAWING: Figure 2B

Isolated circuit systems are provided. The systems include a primary side circuit and a secondary circuit, electrically isolated from each other. The primary side and secondary side circuits each utilize a direct current (DC) reference signal. The primary side circuit may use the DC reference signal in a modulation operation. The secondary side circuit may use the DC reference signal in a demodulation operation. The DC reference signal may be sent from the primary side circuit to the secondary side circuit, or from the secondary side circuit to the primary side circuit.

An isolated circuit system is provided. The system includes a primary side circuit and a secondary side circuit that are electrically isolated from each other. The primary side circuit and the secondary side circuit each utilize a direct current (DC) reference signal. The primary side circuit may use the DC reference signal in a modulation operation. The secondary side circuit may use the DC reference signal in a demodulation operation. The DC reference signal may be transmitted from the primary side circuit to the secondary side circuit or from the secondary side circuit to the primary side circuit.

The present disclosure relates to a charge amplifier circuit (10) for a capacitive sensing arrangement (80), the charge amplifier circuit (10) comprising: - an first amplifier stage (20) comprising a first amplifier input (22), a second amplifier input (23) connectable to the capacitive sensing arrangement (80), and comprising a first amplifier output (24) and a second amplifier output (25), - a second amplifier stage (30) comprising a first amplifier input (32), a second amplifier input (33), a first amplifier output (34) and a second amplifier output (35), and - a switched capacitor arrangement (40) between the first amplifier stage (20) and the second amplifier stage (30), the switched capacitor arrangement (40) comprising a first integration capacitor (42), a second integration capacitor (43), a number of first switches (66, 67) and a number of second switches (68, 69).

A charge amplifier circuit (10) for a capacitive sensing arrangement (80), the charge amplifier circuit (10) including: an first amplifier stage (20) including a first amplifier input (22), a second amplifier input (23) connectable to the capacitive sensing arrangement (80), and including a first amplifier output (24) and a second amplifier output (25), a second amplifier stage (30) including a first amplifier input (32), a second amplifier input (33), a first amplifier output (34) and a second amplifier output (35), and a switched capacitor arrangement (40) between the first amplifier stage (20) and the second amplifier stage (30), the switched capacitor arrangement (40) including a first integration capacitor (42), a second integration capacitor (43), a number of first switches (66, 67) and a number of second switches (68, 69).

The present disclosure relates to a dynamic inductive parametric amplifier comprising an input port arranged to receive a pump tone, a DC bias and an input signal, an output port arranged to provide an amplified version of the input signal, a tunable stepped impedance component arranged to attenuate and / or filter a predetermined frequency band, and a high dynamic inductor line. The tunable stepped impedance component is tuned at a frequency that allows the amplifier to resonate at a predetermined frequency, and the pump tone has a frequency higher than the input signal, and the DC bias signal is sent to the high dynamic inductor line.

An optical receiver includes an optical amplifier that is optically connected to a local oscillator (LO) of the optical receiver and a plurality of optical hybrid mixers and is electrically connected to a controller. The optical amplifier is configured to receive an optical LO signal from the LO, receive a voltage value associated with an optical input signal of the optical receiver, control the power of the optical LO signal based on the voltage value, and, after adjusting the power of the optical LO signal, provide the optical LO signal to the plurality of optical hybrid mixers. The controller is configured to determine the voltage value associated with the optical input signal and cause the voltage value to be provided to the optical amplifier.

Embodiments of the present disclosure relate to a chopper amplifier circuit and a method for operating a chopper amplifier circuit. The present disclosure relates to a chopper amplifier circuit with inherent chopper ripple rejection.

A circuit structure to improve reliability of power line communication has a power line, on which a power energy wave and a network signal are transmitted. The circuit structure includes: a first isolator, which is disposed at an entrance of a power consumption terminal of the circuit structure, separates the power line into the power consumption terminal and a transmission terminal, and filters the network signal, so that the power energy wave enters the power consumption terminal; and a first coupler for generating a first coupling path, through which the network signal enters the transmission terminal via the first coupler without passing through the first isolator. Power line impedance at a side of the transmission terminal is not affected by a side of the power consumption terminal.

Provided is an amplifier capable of outputting a signal component that is not affected by distortion caused by a filter, without reducing the accuracy of removing an error component contained in an input signal. The amplifier includes: a signal polarity inversion circuit; an amplifier circuit which is connected to the signal polarity inversion circuit, generates a current based on the voltage, and outputs the current from an output terminal; a signal polarity inversion circuit having input terminals connected to the output terminals, respectively, and outputting the current output from the amplifier circuit with a normal-phase polarity or a reversed-phase polarity; a capacitor that obtains a voltage based on the current output from the signal polarity inversion circuit; and a compensation circuit which is connected between nodes, extracts an input error component current including the input error component of the amplifier circuit from a voltage between the two terminals of the capacitor, and supplies the extracted input error component current to the nodes.

The present invention discloses a differential signal amplification circuit as well as a digital isolator and a digital receiver applying the differential signal amplification circuit, wherein the differential signal amplification circuit includes a multi-stage differential amplifier and a common-mode transient adaptive biasing circuit. The common-mode transient adaptive biasing circuit is configured to detect a positive or negative common-mode transient interference signal at a positive input terminal and a negative input terminal, and provide a biasing current of a differential amplifier of at least one stage above a second stage when the positive or negative common-mode transient interference signals are detected. With the technical solutions of the present invention, abnormal signal transmission caused by the common-mode interference signals can be suppressed.

The present invention is a Class-D amplifier including: a capacitively-coupled amplifier, configured to receive an input signal and a feedback signal and generate an error signal; and a loop filter, coupled to input capacitor and the feedback capacitor, configured to generate a processed signal according to the error signal; and a pulse-width modulation (PWM) generator, coupled to the loop filter, configured to generate a plurality of PWM signals according to the processed signal and a control signal; and a voltage boosting power stage, coupled to the PWM generator, configured to generate a boosted output signal according to the plurality of PWM signals, the control signal and a power supply, and to feedback the boosted output signal to the loop filter, wherein the maximum voltage of the boosted output signal is greater than the voltage of the power supply.

Provided is a semiconductor circuit that includes a plurality of amplifiers that is connected in series and individually amplify and supply a signal on an input side to an output side. A first chopper switch is connected to an input side of a first amplifier connected first among the plurality of amplifies, and a second chopper switch is connected to an output side of the first amplifier. The first and second chopper switches act in synchronism with a first chopper clock. A third chopper switch is connected to an input side of a second amplifier, and a fourth chopper switch is connected to an output side of the second amplifier. The third and fourth chopper switches act in synchronism with a second chopper clock. A phase compensation capacitor is connected at one end to an input portion of the third chopper switch.

An amplification device in an electro-optical receiver is used to amplify a signal. An amplification device for amplifying a signal having a DC signal component is provided, which includes a coupling and filtering circuit having an input terminal and an output terminal. The coupling and filtering circuit attenuates the DC signal component of the input signal to obtain a filtered output signal. The coupling and filtering circuit includes: a first capacitor circuit connecting the input terminal to the output terminal, the first capacitor circuit including a first capacitor; a second capacitor circuit connected in parallel with the first capacitor circuit, the second capacitor circuit including a second capacitor, a first resistor, and a second resistor, the second capacitor, the first resistor, and the second resistor being connected in series; and a resistor circuit connected to the input terminal and the output terminal and including a third resistor connected to the input terminal and a fourth resistor connected to the output terminal. The amplification device includes an amplification circuit connected to the output terminal, and the amplification circuit amplifies the filtered signal.

Embodiments of an interface circuit, a MicroElectroMechanical system (MEMS) interface circuit, and a method for operating an interface circuit are disclosed. In an embodiment, an interface circuit includes an input chopper circuit configured to apply an excitation voltage to a transducer by pre-charging the transducer with bias voltages in alternating sensing cycles to generate a transducer difference charge, an input common-mode control circuit configured to generate a common-mode voltage in response to the applied excitation voltage, and a capacitance-to-voltage (C / V) and output chopper circuit configured to, in response to the common-mode voltage, integrate transducer difference charge on capacitors to produce an output voltage.

An instrumentation amplifier can include: an input port configured to receive a sensor signal; a first-stage amplifier configured to amplify the sensor signal to obtain a first intermediate signal; a first high-pass filter circuit, having input terminals coupled to output terminals of the first-stage amplifier, and being configured to eliminate a signal that is in the first intermediate signal and associated with an offset voltage of the first-stage amplifier, in order to obtain a second intermediate signal; a first chopper, having input terminals coupled to output terminals of the first high-pass filter circuit, and being configured to perform chopper modulation and demodulation on the second intermediate signal to obtain a third intermediate signal; and a second-stage amplifier, having input terminals coupled to output terminals of the first chopper, and being configured to amplify the third intermediate signal to generate an output signal.

An integrated biopotential chopper amplifier with improved input impedance provided by the present invention reduces the size of the input pair transistors of the fully differential differential amplifier located between the chopper switches and the input capacitors, so as to reduce the equivalent input capacitance. Different from the traditional equivalent input capacitance which is mainly determined by the input capacitance, the equivalent input capacitance of the present invention is determined by the gate parasitic capacitance of the input pair transistors of the DDA structure. Therefore, the equivalent input capacitance can be reduced exponentially to the fF level, thereby greatly increasing the equivalent input impedance of the amplifier.

To provide an amplifier capable of reducing spike noise caused by clock feedthrough of a switch without increasing a chip size.SOLUTION: An amplifier includes: a signal polarity inversion circuit 11 modulating an input signal and outputting a modulation signal; an amplifier circuit 12 constituted from an OTA, amplifying the modulation signal and outputting an electric current based on the amplified modulation signal; and a sample hold circuit 13 that includes a capacitor 135 which can be switched between a state where one end thereof is connected to a first output terminal of the amplifier circuit and the other end thereof is connected to a second output terminal of the amplifier circuit and a state where the one end thereof is connected to the second output terminal of the amplifier circuit and the other end thereof is connected to the first output terminal of the amplifier circuit, and a capacitor 138 which can be connected to the capacitor 135.SELECTED DRAWING: Figure 1

Extended dynamic range of a Micro-Electro-Mechanical System (MEMS) microphone circuit is accomplished in low-noise amplifier circuits and their methods of operation. The circuits are amplifier circuits receive an input signal from a MEMS microphone, and include an input terminal for connection the microphone, a low-noise amplifier having an input coupled to the input terminal, and a capacitively-coupled instrumentation amplifier (CCIA) having an input coupled to an output of the low-noise amplifier. The circuit also includes at least one additional signal path having inputs coupled to the output of the low-noise amplifier and that bypasses the CCIA to provide an alternative signal path, and a switching circuit for clamping the inputs of the CCIA to a common-mode voltage of the circuit while the signal level is greater than the threshold signal level.

Methods and devices for termination of an envelope frequency and harmonics in an RF amplifier are presented. A multifunctional filter is coupled to an RF node of the RF amplifier to provide first and second conduction paths between the RF node and first / second low impedance nodes. The first conduction path provides a low impedance at the envelope frequency and high impedances at an operating frequency of the RF amplifier and corresponding higher order harmonics. The second conduction path provides a low impedance at the higher order harmonics and high impedances at the envelope frequency and at the operating frequency. The multifunctional filter includes first / second inductors in series connection between the RF node and the first low impedance node. According to one aspect, the first / second inductors are coupled to first / second capacitors to respectively form a tank circuit and a trap circuit operating at the frequencies of the harmonics.

A system and method for a drift reset circuit for updating the input offset voltage in an ionization smoke detector are disclosed. The method may include monitoring an ionization chamber of a smoke detector for an alert. The method may also include periodically powering on a drift reset circuit to update an input offset voltage of an operational amplifier. The method may additionally include outputting the input offset voltage to the operational amplifier. The method may further include powering off the drift reset circuit.

A chopper amplifier circuit includes a modulator circuit tuned to a chopper frequency, the modulator circuit being configured, in accordance with the chopper frequency, to convert a voltage into an AC voltage; an amplifier circuit having an inverting input and a non-inverting input for the AC voltage, and having an inverting output and a non-inverting output for providing an amplified AC voltage; and a demodulator circuit tuned to the chopper frequency, the demodulator circuit being configured to convert the amplified AC voltage into an amplified DC voltage. The demodulator circuit is configured to, during different switching phases, couple each of the inverting and non-inverting outputs of the amplifier circuit, both directly and capacitively, to each inverting and non-inverting input of a summing circuit.

Described embodiments include an apparatus with a first amplifier having first inputs and first outputs. A second amplifier has second inputs and a second output. A first chopper circuit is coupled between third inputs and the first inputs. A second chopper circuit is coupled between the first outputs and the second inputs. A balanced filter is coupled to the second inputs.

The invention discloses a precise chopping instrument amplifier realized by utilizing automatic zero calibration. The precise chopping instrument amplifier comprises an automatic zero calibration module, a chopping modulation and demodulation module and a precise operational amplifier module. The whole circuit structure is a chopping stabilized amplifier. Before the amplifier works, the input of a high-frequency path and the input of a low-frequency path are short-circuited, and an output voltage value is fed back to the IDAC through automatic zero calibration logic, so that random mismatch caused by production and system mismatch existing in the circuit are eliminated, and residual input offset voltage after chopping is effectively eliminated; the precision of the amplifier is improved, and the area of the circuit is reduced. The method is suitable for high-precision measurement application.

To provide an amplifier capable of outputting a signal component, which is not affected by distortion caused by a filter, without reducing removal accuracy of an error component included in an input signal.SOLUTION: An amplifier 100 comprises: a signal polarity inversion circuit 200; an amplifier circuit 301 which is connected to the signal polarity inversion circuit 200 and in which a current based on a voltage Vb is generated and outputted from output terminals OUTP1 and OUTN1; a signal polarity inversion circuit 201 which includes input terminals respectively connected to the output terminals OUTP1 and OUTN1 and outputs the current outputted from the amplifier circuit 301 with a polarity of a positive phase or a reverse phase; a capacitor CL which obtains a voltage based on the current outputted from the signal polarity inversion circuit 201; and a compensation circuit 350 to which a node 12 and a node 10 are connected and a node 13 and a node 11 are connected and which extracts an input error component current including an input error component of the amplifier circuit 301 from a voltage between both terminals of the capacitor CL and supplies the extracted input error component current to the node 10 and the node 11.SELECTED DRAWING: Figure 1

An amplifier includes: a signal polarity inversion circuit; an amplifier circuit, connected with the signal polarity inversion circuit, generating a current based on a voltage, and outputting the current from output terminals; a signal polarity inversion circuit, having input terminals respectively connected with the output terminals, and outputting, in a non-inverted or inverted polarity, the current output from the amplifier circuit; a capacitor, obtaining a voltage based on the current output from the signal polarity inversion circuit; and a compensation circuit, wherein a node 12 and a node 10 are connected and a node 13 and a node 11 are connected, an input error component current comprising an input error component of the amplifier circuit is extracted from a voltage between terminals of the capacitor, and the input error component current that is extracted is supplied to the node 10 and the node 11.