17results about "Dc amplifiers with modulator-demodulator" patented technology

A signal processing device and a signal transceiver device are provided. The signal processing device includes a first amplifier, two first choppers, a second chopper, and a third chopper. The first amplifier is configured to generate a second signal from a first signal. The two first choppers are embedded between an input and an output of the first amplifier and are configured to perform a first frequency shift and a first frequency shift back, respectively. The second chopper is coupled to the input of the first amplifier and is configured to perform a second frequency shift. The third chopper is coupled to the output of the first amplifier and is configured to perform a second frequency shift back. The first frequency and the second frequency are different.

A delta sigma type ADC (1) is provided with a quantizer (30) operating at a prescribed sampling frequency (fs), an FIR filter (40) connected to the quantizer (30), and a DAC (50). A feedback path for the quantizer (30) is structured by the FIR filter (40) and the DAC (50). A reference signal for the DAC (50) is supplied from a reference signal source (60) chopping at a frequency lower than the prescribed sampling frequency (fs).

This application relates to methods and apparatus for clipping prevention. A driver apparatus for driving a load with an output signal has a switching driver with a switch network and a modulator configured to control the switch network to switch output nodes between different switching voltages with a controlled duty-cycle. A quantizer controller receives a quantizer input signal based on an input signal and a feedback signal and controls the duty-cycle of the switch network. A clipping prevention controller is configured to control a gain applied to the input signal so as to provide limiting of the input signal to avoid clipping, wherein the clipping prevention controller is configured to dynamically control at least one limiting threshold used to determine when to apply limiting of the input signal based on an indication of said quantizer input signal.

The present application discloses an isolation amplifier circuit. The isolation amplifier circuit comprises a modulation circuit, an isolation circuit, and a demodulation circuit. The modulation circuit receives an input signal and a first clock signal, and generates a first modulation signal and a second modulation signal according to the first clock signal and the input signal. The isolation circuit receives a second clock signal, the first modulation signal, and the second modulation signal, generates a first clock signal according to the second clock signal, generates a first demodulation signal according to the first modulation signal, and generates a second demodulation signal according to the second modulation signal. The demodulation circuit receives the first demodulation signal, the second demodulation signal, and the second clock signal, and generates an output signal according to the second clock signal, the first demodulation signal, and the second demodulation signal. In the present application, quantization noise generated by a first modulation circuit is canceled by performing, in a demodulation circuit, weighted summation of a second demodulation signal, generated according to the second modulation signal, with the demodulated first modulation signal, thereby achieving low noise in an isolation amplifier circuit.

To provide electronic circuitry and a power converter, capable of suppressing degradation in performance due to transmission of a signal through electromagnetic field coupling.SOLUTION: Electronic circuitry according to the present embodiment includes: a clock generation circuit configured to generate a first clock signal; a first conversion circuit configured to convert an input signal into a first signal having a frequency corresponding to the first clock signal on the basis of the first clock signal; a first electromagnetic field coupler configured to transmit the first signal by electromagnetic field coupling; a second electromagnetic field coupler configured to transmit the first clock signal by the electromagnetic field coupling; and a second conversion circuit configured to convert the first signal transmitted by the first electromagnetic field coupler into a second signal having a frequency corresponding to the input signal, on the basis of the first clock signal transmitted by the second electromagnetic field coupler.SELECTED DRAWING: Figure 1

Provided is an implementation method of a novel low-distortion digitally modulated direct-drive power amplifier apparatus. The method can achieve acquisition of modulated waveform signals by Δ-Σ oversampling technique, and further improves a sampling rate of the modulated waveform signals by an interpolated filter. An exciter can generate multiphase PDM modulated waveform pulses and carrier drive pulses to directly drive power amplifier modules to complete carrier generation and waveform modulation. However, to reduce complexity of a system and take the modulated waveform THD indicators into account, the multiphcontrolled within 12 phases.

An optical light sensing device includes a detector operable to detect a light wave. The optical light sensing device also includes an integration circuit that includes an operational amplifier that is operable to reduce or cancel dark currents generated at the detector.

A sensor readout system (100) is provided. The sensor readout system (100) comprises a signal generator (101) configured to generate a biasing signal (102), a first chopper (103) configured to modulate the biasing signal (102) using a chopping signal (117) with a chopping frequency fchop to generate a modulated biasing signal (104) . It also comprises a Wheatstone bridge circuit (105) comprising four resistive branches (R1, R2, R3, R4), at least one of the four resistive branches comprises an impedance-based sensor (Rs1, Rs2, Rs3). The Wheatstone bridge circuit (105) is configured to receive the modulated biasing signal (104) and to generate a sensing signal (106) based on the modulated biasing signal (104). A second chopper (107) is configured to modulate the sensing signal (106) using the chopping signal (117) with the chopping frequency fchop to generate a modulated sensing signal (108) .

The application relates to a chopping operational amplifier circuit applied to voltage isolation, which mainly comprises transconductance amplifiers amp1, amp2, amp3, amp4, amp5, chopping modulation circuits CHIN, CHOUT, CHfb, CHRRL, capacitors Cin1, Cin2, Cfb1, Cfb2, Cs1, Cs2, Cm1, Cm21a, Cm21b, Cm22a, Cm22b, resistors res1, res2, and a chopping modulation signal f chop The chopping modulation circuit CHIN modulates the analog voltage signal input from the high-voltage end into a voltage signal with a frequency of f chop , and couples the voltage signal to the low-voltage end through the isolation capacitors Cin1 and Cin2; the bias resistors res1 and res2 of the low-voltage end provide the transconductance amplifier amp1 of the low-voltage end with a direct current bias signal again; the CHOUT modulates the offset voltage V OFFSET of the transconductance amplifier amp1 and the 1 / f noise into high frequency, and re-modulates the output current signal of the amp1 into the frequency input from the high-voltage end; finally, the size of the output voltage is input signal Vout=Vin x (Cfb / Cin), and the ripple elimination ring eliminates the ripple generated by the offset voltage of the transconductance amplifiers amp1, amp2 and amp3.

The present invention relates to the field of plasma generation radio-frequency power supplies, and provides a method for implementing a novel low-distortion digital-modulation direct-drive power amplifier device. In the method, the acquisition of a modulated waveform signal is achieved by using a Δ-Σ oversampling technique, the sampling rate of the modulated waveform signal is further improved by means of an interpolation filter within a PDM pulse distribution unit, and an exciter can generate a multi-phase PDM modulated waveform pulse and a carrier drive pulse, thereby directly driving a power amplifier module to complete carrier generation and waveform modulation. Multi-phase PDM modulation can achieve a better total harmonic distortion (THD) index of a modulated waveform, ensuring that a modulated waveform signal is basically restored without any distortion; however, in order to reduce system complexity and take into account the THD index of the modulated waveform, multi-phase PDM modulation is generally controlled to be within 12 phases. In addition, a modulated waveform signal is divided into multiple equal-amplitude PDM square-wave signals by means of multi-phase PDM modulation and a superposition technique, allowing a power amplifier to operate in a switching state, thereby improving the efficiency of the power amplifier.

To provide an amplifier in which an input offset current is reduced.SOLUTION: The auto-zero amplifier circuit 2122 includes a transconductance amplifier 211221 and sampling capacitors CM1 and CM2. A modulation chopper circuit 31,32 modulates an input signal and inputs the modulated signal to a mutual conductance amplifier 211,221. The auto-zero switch circuit 41 includes auto-zero switches S31 and S32, and the auto-zero switch circuit 42 includes auto-zero switches S33 and S33. An isolation resistor R1 is connected between the connection point of the auto-zero switches S31 and S32 and INM. An isolation resistor R2 is connected between the connection point of the auto-zero switches S33 and S34 and INM.SELECTED DRAWING: Figure 1

Disclosed is a bidirectional amplifier. The bidirectional amplifier includes a first matching circuit, a second matching circuit, an amplifier circuit connected between the first matching circuit and the second matching circuit, that amplifies a first input signal received from the first matching circuit to output the amplified first input signal to the second matching circuit, and that amplifies a second input signal received from the second matching circuit to output the amplified first input signal to the first matching circuit, and the first and second matching circuits have a symmetrical structure and operate complementary to each other.

A signal processing device and a signal transcciving device are provided. The signal processing device includes a first amplifier, two first choppers, a second chopper, and a third chopper. The first amplifier is configured to generate a second signal according to a first signal. The two first choppers are embedded between an input end and an output end of the first amplifier and respectively configured to perform a shifting operation of a first frequency and a shifting back operation of the first frequency. The second chopper is coupled to the input end of the first amplifier and configured to perform a shifting operation of a second frequency. The third chopper is coupled to the output end of the first amplifier and configured to perform a shifting back operation of the second frequency. The first frequency and the second frequency are different.

A device includes a sensor signal input node and a high-pass filter stage. The high-pass filter stage includes an operational amplifier and a feedback integrator. The operational amplifier includes an input node coupled to the sensor signal input node. The feedback integrator is coupled between an output node of the operational amplifier and the input node of the operational amplifier to set a high-pass pole frequency of the high-pass filter stage.

This invention provides a Class AB amplifier that reduces the influence of the chopper switch's on-resistance on the circuit characteristics. [Solution] The Class AB amplifier 100 includes an input chopper switch circuit CSW1 that performs chopping operations in synchronization with the first and second chopper clock signals PHI and PHIB to modulate the first and second differential input signals VINN and VINP, and outputs the first and second modulated signals VA1 and VA2 to the first and second nodes Q1 and Q2; an input amplifier circuit AM1 that receives the first and second modulated signals via the first and second nodes and outputs a differential amplifier signal amplified from the first and second modulated signals; an output chopper switch circuit CSW2 that receives the differential amplifier signal, performs chopping operations in synchronization with the first and second chopper clock signals to modulate the differential amplifier signal, and outputs demodulated signals D1 to D4 demodulated to the frequency band of the first and second differential input signals; and an output amplifier circuit AM2 that outputs a first output signal VOP, which is an amplified demodulated signal, via the first output terminal TOP.

This provides an amplifier circuit configuration that can reduce circuit area and power consumption. [Solution] The input selector switch 110 modulates the input signal Sin into a first signal S1 with a predetermined operating frequency and inputs it to an amplifier 120 which has a built-in frequency conversion switch 125. The amplifier 120 is configured such that, as the frequency conversion switch 125 works in coordination with the input selector switch 110, the first signal S1 is amplified inside the amplifier and the amplified signal is demodulated by the frequency conversion switch 125, thereby outputting a second signal S2 with the same frequency as the input signal Sin. The filter 130 outputs a signal S3 obtained by attenuating or removing the component of the operating frequency of the frequency conversion switch 125 from the second signal S2 output from the amplifier 120.

Example embodiments relate to sensor readout systems and sensor readout methods. One example sensor readout system includes a signal generator configured to generate a biasing signal. The sensor readout system also includes a first chopper configured to modulate the biasing signal using a chopping signal with a chopping frequency fchop to generate a modulated biasing signal. Additionally, the sensor readout system includes a Wheatstone bridge circuit that includes resistive branches. At least one of the resistive branches includes an impedance-based sensor. The Wheatstone bridge circuit is configured to receive the modulated biasing signal and to generate a sensing signal based on the modulated biasing signal. Further, the sensor readout system includes a second chopper configured to modulate the sensing signal using the chopping signal with the chopping frequency fchop to generate a modulated sensing signal.