112 results about "Common mode feedback" patented technology

This disclosure describes an apparatus that enables rapid transitions during microwave-assisted magnetic recording (MAMR) of storage media. In various aspects, the apparatus incorporates a driver circuit configured to provide a controlled bias current through separate source and sink output terminals, which respond to feedback signals. An MAMR sensor connects between the source and sink output terminals and generates microwave fields when receiving the controlled bias current from the driver circuit. A common-mode feedback (CMFB) loop connects to the source and sink output terminals, detects common-mode voltage (CMV), and delivers feedback signals to the driver circuit to maintain CMV regulation of the MAMR sensor. A differential voltage regulation loop connects to the source and sink output terminals, providing feedback signals that maintain the MAMR sensor voltage differential at a reference value. The apparatus controls the magnetic recording process of the MAMR sensor with rapid transition times.

The invention discloses an amplitude-adjustable attenuation circuit network for differential signal transmission. The amplitude-adjustable attenuation circuit network is composed of an attenuator I and an attenuator II. Wherein a common-mode feedback circuit is arranged between the attenuator I and the attenuator II. The attenuator I is introduced into an anti-ESD impact module which is composed of an input end back-to-back diode and used for resisting ESD impact. Differential signals at the input end of the attenuator I are subjected to voltage division through fixed resistors RS1 and RS1 < n > and binary weight adjustable resistors RS2 and RS2 < n >, the attenuator II is connected to a transmission channel in parallel, and the differential signals are subjected to further differential mode attenuation through binary weight adjustable capacitors CSp and CSn. The attenuation circuit network dynamically switches attenuation paths through an MOS tube switch matrix, respectively supports attenuation amounts from-1dB to-6dB and from-0.3 dB to-7dB, realizes high stepping precision, finally realizes synchronous attenuation for common-mode and differential-mode voltages, retains differential-mode attenuation of common-mode levels, and optimizes low-frequency amplitude attenuation and high-frequency signal integrity at the same time.

The invention relates to a low-power-consumption high-performance D-type power amplifier modulation method and circuit and a D-type audio power amplifier, and the method comprises the steps: separating a pair of BD mode modulated signals outputted by a PWM modulation module in the D-type audio power amplifier circuit into a common mode component and a differential mode component, and outputting the common mode component and the differential mode component; feeding back the common-mode component and the differential-mode component to a differential input end through a common-mode feedback link and a differential-mode feedback link respectively; wherein the common-mode component and the common-mode feedback link are completely arranged in the chip; the differential mode component and the differential mode feedback link are realized by a power MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) integrated inside the chip or an external power MOSFET; and outputting the differential mode component to a to-be-driven object through the power output stage. According to the method, after two feedback links are separated, in a zero-input mute state, no common-mode signal is sent to an output stage for amplification, and power consumption is not caused at the output stage, so that the overall efficiency is greatly improved; and meanwhile, static bottom noise is almost eliminated.

The application provides a common-source common-gate amplifier, comprising a signal input module, which is used for generating an input signal according to a power supply voltage; a cross-coupling module, which is electrically connected with the signal input module and is used for forming internal positive feedback according to an output signal; a first biasing module, which is electrically connected with the cross-coupling module; a first branch module, which is electrically connected with the first biasing module; a second biasing module, which is electrically connected with the cross-coupling module; a second branch module, which is electrically connected with the second biasing module; wherein the first biasing module and the second biasing module are used for providing biasing after an input common-mode feedback voltage, the first branch module and the second branch module are used for providing large-swing output biasing, and the first branch module and the second branch module are respectively electrically connected with the signal input module, and the signal input module is further used for outputting branch signals to the first branch module and the second branch module. The application improves the voltage swing, the gain and the bandwidth of the circuit under the single-stage amplifier structure.

This application provides an operational amplifier that increases the stability and settling speed of a common-mode feedback circuit. The operational amplifier includes N stages of amplifiers connected in series and M common-mode feedback circuits, where N and M are integers, N≥3, and N≥M>1. An ith common-mode feedback circuit in the M common-mode feedback circuits is configured to: detect a common-mode output voltage of a (j+b)th stage of amplifier, and regulate an electrical parameter of at least one of the jth stage of amplifier to the (j+b)th stage of amplifier, to stabilize the common-mode output voltage of the (j+b)th stage of amplifier. An Mth common-mode feedback circuit is configured to detect and stabilize a common-mode output voltage of an Nth stage of amplifier. Herein i, j, and b are integers, M≥i≥1, N≥j≥1, i≥j, j+b≤N, and b≥0.

This application provides a buffer and chip. The buffer includes a first conversion circuit, a second conversion circuit, and a common-mode feedback circuit. The first conversion circuit outputs a first output signal based on a first input signal, a first bias voltage, and a first substrate bias voltage of a first main input transistor. The first substrate bias voltage includes an initial and an adjusted first substrate bias voltage. The second conversion circuit outputs a second output signal based on a second input signal, the first bias voltage, and a second substrate bias voltage of a second main input transistor. The second substrate bias voltage includes an initial and an adjusted second substrate bias voltage. The common-mode feedback circuit generates a common-mode signal based on the first and second output signals. Based on the common-mode signal and a target voltage value, it generates and adjusts the first and second substrate bias voltages based on the feedback signal. Because the common-mode feedback circuit adjusts the substrate voltage of the main input transistor, it maintains the stability of the common-mode signal, thereby improving the linearity and stability of the buffer.

This invention relates to the field of high-resolution time measurement systems and integrated circuit technology, providing a time measurement circuit with a two-dimensional address-modulated TOT pulse, comprising: a common-gate transimpedance amplifier, a high-speed high-gain comparator, a current-mode logic output stage, a common-mode feedback threshold setting circuit, and a two-dimensional address-modulated TOT pulse circuit; the address modulation pulse circuit includes an address modulation pulse width circuit and an address modulation pulse amplitude circuit, wherein the address modulation pulse width circuit includes: multiple sets of first modulation units, multiple sets of second modulation units, multiple inverters, and multiple bits of first digital code; the address modulation pulse amplitude circuit includes: multiple sets of third modulation units and multiple bits of second digital code. This invention allows a single TOT signal to simultaneously carry time information, energy information, and address information, reducing wiring, improving reliability, and increasing integration density.

The invention provides an operational amplifier and a layout structure thereof. The layout structure comprises a first layout area, a second layout area and a third layout area which are sequentially arranged along a first direction, a first compensation capacitor array area and a second compensation capacitor array area are respectively arranged in the first layout area and the third layout area; a differential pair transistor region, a first common-mode feedback region, a first load region, a second load region, a second common-mode feedback region and an amplifying circuit output region which are sequentially arranged along a second direction are arranged in the second layout region, and the first chopping region and the second chopping region are arranged on two sides of the first load region or the second load region along the first direction; the first chopping region is close to the first layout region, and the second chopping region is close to the third layout region. According to the method, the layout design work of the differential pair in the simulation layout design can be effectively and quickly realized, the process dependence is reduced, the structure of the differential pair can be strictly controlled, and the high symmetry is ensured.

This invention relates to the field of communication technology and discloses a circuit and electronic device for driving a passive mixer for up-conversion. The common-mode voltage of the differential signal is adjusted through a common-mode feedback adjustment network, and the adjusted voltage flows to a common-mode voltage control circuit. A drive control circuit outputs a drive control signal based on the differential signal to power the passive mixer. The common-mode voltage control circuit outputs a voltage control signal based on the adjusted voltage and a reference voltage, ensuring the common-mode voltage is regulated by the common-mode feedback adjustment network. Therefore, implementing this invention enables precise driving of the passive mixer through the processing of the differential signal by the drive control circuit. This is beneficial for improving the mixing gain of the passive mixer through drive control based on the drive control circuit, and it can improve the stability of the differential signal by setting up the common-mode feedback adjustment network and the common-mode voltage control circuit, thereby reducing the impact on the noise, bandwidth, and linearity of the mixing system.

This invention provides a transmitter circuit for a CAN bus, relating to the field of CAN bus communication. The circuit includes: a common-mode feedback circuit for generating first and second gate voltages; a slew rate control circuit comprising a CANH terminal circuit for receiving the first gate voltage and a CANL terminal circuit for receiving the second gate voltage, each terminal circuit including multiple sequentially connected delay units and power transistors, the delay units controlling the gate voltage of the power transistors stage by stage to alternately switch the power transistors; and a port positive and negative high-voltage protection circuit, respectively connected between the output terminals of the CANH and CANL terminal circuits and the bus port, for protecting against positive and negative high voltages on the bus and suppressing parasitic effects. The beneficial effects are: by controlling the switching of the power transistors stage by stage through the delay units, the current surge rate is reduced, and electromagnetic radiation is reduced; by stabilizing the gate voltage and balancing the output current through common-mode feedback, signal symmetry is improved and common-mode interference is suppressed.

The invention discloses a fully differential amplifier circuit with rail-to-rail output. The fully differential amplifier circuit comprises a main amplifier circuit, a first-stage common-mode feedback circuit, a second-stage common-mode feedback circuit and a voltage regulation circuit. The main amplifier circuit comprises a first-stage main amplifier and a second-stage main amplifier which are cascaded; the first-stage common-mode feedback circuit comprises an amplifier Af1, a first input end of the amplifier Af1 is connected to the first-stage differential output end, a second input end of the amplifier Af1 is connected with a first reference voltage end, and the amplifier Af1 compares common-mode voltage output by the first-stage main amplifier with first reference voltage VREF1 and feeds back error quantity to the first-stage main amplifier; the second-stage common-mode feedback circuit comprises an amplifier Af2; the input end of the voltage adjusting circuit is connected with the output end of the amplifier Af2, and the output end of the voltage adjusting circuit provides adjustable first reference voltage for the first reference voltage end. According to the circuit, it can be guaranteed that the output common-mode level is fast and stable, and rail-to-rail output is achieved.

The invention discloses a bipolar voltage-time converter based on phase inverter threshold detection. The bipolar voltage-time converter is characterized in that a differential sampling circuit is connected with a sign bit comparator and a bipolar voltage-time conversion circuit; the sign bit comparator is used for receiving the differential sampling voltage output by the differential sampling circuit and judging the polarity of an input differential analog signal, and is connected with the bipolar voltage-time conversion circuit to output a sign bit signal and a polarity control signal; the bipolar voltage-time conversion circuit is used for charging or discharging the differential sampling voltage under the control of the polarity control signal to generate two paths of voltage ramp signals with opposite polarities, and is connected with the common-mode feedback circuit and the inverter threshold detection circuit; the common-mode feedback circuit is used for detecting a common-mode level of the differential sampling voltage or two paths of voltage ramp signals; the threshold voltage of the inverter threshold detection circuit is configured to be a predetermined common-mode level, and is used for detecting a crossover event of the two voltage ramp signals at the predetermined common-mode level and outputting a threshold detection signal.

The present disclosure describes aspects of a differential current-mode (iMode) driver for microwave-assisted magnetic recording (MAMR) application in hard-disk drives. In some aspects, an iMode driver circuitry employs a driver circuit coupled to power supply connections. The driver circuit is configured to provide a controlled differential bias current and includes separate source and sink output terminals. A MAMR sensor couples between the source and sink output terminals, through which the MAMR sensor receives the controlled differential bias current provided by the driver circuit. The MAMR sensor, which has a field-entry terminal and a field-exit terminal, generates microwave fields for the recording process. A common-mode feedback (CMFB) loop couples to the field-entry and field-exit terminals of the MAMR sensor, forming a feedback pathway with the driver circuit. This CMFB loop detects common-mode voltage (CMV) and adjusts the controlled differential bias current to maintain CMV regulation of the MAMR sensor.

In some aspects, the disclosure is directed to methods and systems for an amplifier having common mode feedback inputs. The inputs are coupled to various points within an amplifier wherein a first set of directly coupled common mode feedback inputs join the amplifier one or more nodes, and a second set of capacitively coupled common mode feedback inputs are joined to the amplifier at one or more different nodes.

The present invention discloses a common-mode feedback circuit, control method, and operational amplifier, relating to the field of circuit design technology. The common-mode feedback circuit includes: a common-mode sensing and error amplification subcircuit and a current summing subcircuit for providing a common-mode feedback voltage; the current summing subcircuit is coupled to the common-mode sensing and error amplification subcircuit; the common-mode sensing and error amplification subcircuit includes two sets of differential amplifier input transistors with opposite polarity, each set of differential amplifier input transistors including two pairs of transistors with the same polarity, one transistor in each pair of transistors being controlled by a differential output signal, and the other transistor being controlled by a common-mode signal. The control method described above applies to the common-mode feedback circuit. The operational amplifier described above includes the common-mode feedback circuit.

The invention relates to the technical field of analog-to-digital conversion, and discloses a ring amplifier and an analog-to-digital converter, the ring amplifier comprises a cascade phase inverter and two short-circuit phase inverters, and each stage of phase inverter of the cascade phase inverter comprises two single-stage phase inverters; each of the short-circuit phase inverter and the single-stage phase inverter comprises two complementary MOS (Metal Oxide Semiconductor) tubes; the grid electrodes of the two MOS tubes of the short-circuit inverter are in short circuit with the drain electrodes of the two MOS tubes of the short-circuit inverter; the control voltage and the input voltage of the ring amplifier are accessed to the first-stage inverter in the cascaded inverters, and the control voltage is the output voltage of a common-mode feedback circuit of the ring amplifier; and the drain electrode of the output-stage phase inverter in the cascaded phase inverters is used as the differential output end of the ring amplifier. The short-circuit inverter is used for replacing a resistor in the related technology, so that dead-zone voltage is effectively avoided, and the ring amplifier can output stable differential signals.

A common-mode feedback circuit for a fully differential amplifier comprises first (MB), second (MTP), and third (MTN) transistors, each having a respective drain, source, gate, and back-gate terminals. The drain terminal of the first transistor (MB) and the gate terminals of the first, second, and third transistors (MB, MTP, MTN) are connected together at a bias current terminal. The drain terminals of the second and third transistors are connected together at a tail current terminal. The source terminals of the first, second, and third transistors are connected together. The back-gate terminal of the first transistor (MB) is arranged to receive a common-mode reference voltage input (VCM), the back-gate terminal of the second transistor (MTP) is arranged to receive a positive output voltage (VP) from the fully differential amplifier, and the back-gate terminal of the third transistor (MTN) is arranged to receive a negative output voltage (VN) from the fully differential amplifier.

An operational amplifier includes a first stage of the current-reuse type; and a second stage of the rail-to-rail type, cascaded with respect to the first stage. The first stage comprises a first feedback assembly configured to define a first common mode feedback loop. The second stage comprises a second feedback assembly configured to define a second common mode feedback loop. The first and second common mode feedback loops, of the first and second stages, respectively, are independent of each other.

A signal amplifying circuit includes an amplifier and a common mode feedback circuit. The amplifier generates first and second outputs. The common mode feedback circuit receives the first and second outputs, and controls an output common mode voltage of the first and second outputs to a first reference voltage. The common mode feedback circuit includes an output common mode voltage detection circuit, a pull-up circuit and a pull-down circuit. The output common mode voltage detection circuit generates first and second control signals according to the output common mode voltage. The pull-up circuit with a first conduction degree controlled by the first control signal controls the output common mode voltage to be positively correlated with the first conduction degree. The pull-down circuit with a second conduction degree controlled by the second control signal controls the output common mode voltage to be negatively correlated with the second conduction degree.

The embodiment of the utility model provides a fully-differential amplification circuit, a chip and electronic equipment, the fully-differential amplification circuit comprises a fully-differential amplification module and a common-mode feedback module, and the common-mode feedback module comprises a voltage acquisition unit, a piezoelectric conversion unit, a mirror image unit and a feedback output unit. A feedback loop of common-mode voltage is realized through the voltage acquisition unit, the piezoelectric conversion unit, the mirror image unit and the feedback output unit, and the feedback loop is prevented from using a voltage comparator, so that the use number of transistors in the feedback loop is reduced, and the cost and the occupied area are further reduced.