Abstract: An interface system couples a fixed impedance device to a receiver for transmitting data signals at different data rates at different times. The interface system includes elements that are connected to provide different time constants of responsiveness to data signals of higher and lower data rates without distorting the data signals beyond usability.

Abstract: A modulator apparatus operating at a low supply voltage, configured for receiving an input-voltage signal in base band and supplying an output-voltage signal at a given modulation frequency under control of a signal generated by a local oscillator and comprising a transconductor stage that carries out a voltage-to-current conversion of said input-voltage signal. A voltage-to-current conversion module is coupled to a current-mirror module configured for mirroring a current in a Gilbert-cell stage, which supplies an output-voltage signal under the control of said signal generated by the local oscillator. The Gilbert-cell stage further comprises an output load for carrying out a current-to-voltage conversion and supplying the output-voltage signal. Said transconductor stage further comprises a differential feedback network configured for reproducing said input-voltage signal on a differential load included in said voltage-to-current conversion module.

Abstract: A comparator circuit includes a differential amplifier circuit, a latch circuit, and a control signal generating circuit. The latch circuit includes a pair of cross-coupled inverting amplifiers that pull the output signals of the differential amplifier to the high and low logic levels, a control transistor that activates the latch circuit in synchronization with a clock signal, and an equalizing transistor that equalizes the output signals when the latch circuit is inactive. The equalizing transistor is switched on and off by a control signal generated from the clock signal by the control signal generating circuit. The high-level potential of the control signal is lower than the high-level potential of the clock signal. Switching noise at the control electrode of the equalizing transistor is therefore reduced, permitting high-speed operation.

Abstract: A tuning method and a tuning apparatus for tuning a filter are disclosed. The tuning method includes: configuring the filter as a VCO; utilizing the VCO to generate an oscillation signal according to a driving signal; comparing a frequency of the oscillation signal with a reference frequency to generate a comparison result; converting the comparison result into the driving signal in order to establish a feedback mechanism. Therefore, the inner components such as the gm and capacitance inside the VCO are completely tuned when the VCO generates an oscillation signal having a wanted frequency. Since the VCO is inside the filter and the components of the filter and the VCO are similar, the driving signal can be utilized to make the filter operate in a desired center frequency under a well-designed relationship between the frequency of the oscillation signal and the center frequency.

Abstract: A clock distribution circuit for suitably generating, transmitting, and receiving clock signals used in circuits that are configured with the same circuit topology is provided. The clock distribution circuit has a transmission buffer circuit that transmits a clock signal and an amplitude amplification buffer circuit that amplifies the amplitude of cross-coupling connections inserted in parallel with the transmission buffer circuit on a transmission path for the clock signal. Wherein the number of transistors having the same conductivity type as the transistors of a differing conductivity type of the transmission buffer circuit and that of the transistors of a differing conductivity type of the amplitude amplification buffer circuit are the same. At least one transistor is provided as a bias adjustment transistor for adjusting bias in each of the transmission buffer circuit and the amplitude amplification buffer circuit, respectively, and bias adjustments are made simultaneously.

Abstract: Disclosed is a transconductor including: first and second transistors each having first and second gates, the first and second gates being independently controlled, differential voltage input being supplied between the one first gate and the other first gate, the one source and the other source being connected, a first control voltage being commonly given to both of the second gates, and the drains being differential current output terminals; third and fourth transistors each having the same connection as the first and second transistors, each of the one drain and the other drain being connected with either of the one drain and the other drain of the first and the second transistors so that polarities are opposite to each other; and a current source connected with both of the sources of the first and the second transistors and both of the sources of the third and the fourth transistors.

Abstract: Methods and apparatus for properly biasing differential comparators are provided. Using a feedback relationship, a bias for a main stage that receives a first differential input of the comparator is produced. Separately, a feedback relationship produces a bias for a main stage that receives a second differential input. These biases, produced as a result of the feedback relationship between bias stages and stages that replicate the main stages, are applied to the main stages. The outputs of the differential comparator are differential outputs with improved common-mode rejection as a result of the feedback and replica biasing.

Abstract: In a semiconductor device and method for decreasing noise of an output driver block, the semiconductor device monitors differentially amplified voltages output from an output driver block and controls a voltage level at a cross-over point between the differentially amplified voltages so that noise that may be caused by reactance occurring in the output driver block can be removed and so that inter-symbol interference (ISI) that may be caused when a voltage level of a serialized input data is interfered with a voltage level of previously input data can be prevented.

Abstract: An input voltage circuit comprises an input transistor having a control electrode for receiving a variable input voltage, a voltage detection transistor having a current electrode coupled to a current electrode of the input transistor forming a first node, and a current source coupled to a second current electrode of the voltage detection transistor forming a second node. The input voltage circuit further comprises a variable voltage drop transistor having a first current electrode coupled to the first node, a control electrode coupled to the second node and a second current electrode coupled to an output node, wherein the voltage detection transistor detects a variation in the variable input voltage and provides a signal to the variable voltage drop transistor. The variable voltage drop transistor generates a voltage drop proportional to the variation in the variable input voltage to ensure a substantially constant output at the output node.

Abstract: Current feedback amplifiers circuits that generate common mode (CM) and/or differential mode (DM) currents are provided herein. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures and the claims.

Abstract: A differential circuit including a differential amplifier circuit having a differential element provided in a signal input circuit, a constant current source connected to the differential element, and loads respectively connected to the differential element, and a source follower circuit that outputs a differential voltage based on voltage drops developing across the loads, includes a current supply circuit that supplies a given current to the loads connected in series with the differential element when the differential element is off.

Abstract: The present invention relates to an input circuit for receiving an input signal in an integrated circuit, having a differential amplifier whose first input can have a predetermined reference voltage applied to it and whose second input can have the input signal applied to it, and having a current source for operating the differential amplifier at its operating point, wherein a setting circuit is connected to the current source in order to set the operating point of the differential amplifier in an optimum manner on the basis of the predetermined reference voltage.

Abstract: An electric power circuit for driving a display panel, which supplies a plurality of gradation voltages to driver parts of the display panel, is provided. The electric power circuit has a fine-controlling circuit for fine-controlling the gradation voltage in response to a difference between the gradation voltage and a referential voltage, by which excess increase and decrease of the gradation voltage can be appropriately suppressed. Therefore, the electric power circuit can generates a stable gradation voltage.

Abstract: A differential current driver has a current source that supplies current selectively to two output terminals according to data to be transmitted. A comparison circuit compares the current output by the current source with a reference value and generates a control signal. Responding to the control signal, a current adjustment circuit adjusts the current supplied to the two output terminals by, for example, shunting part of the current to ground, or by adjusting a bias voltage that controls the current output of the current source. A switching circuit may shunt all of the current output by the current source during a brief period preceding output of current from the output terminals. These operations take place around transitions from the output disabled state to the output enabled state, and avoid the output of excessive current just after such transitions.

Abstract: A differential receiver circuit receives a differential input signal including first and second input signals (DP, DM) and generates a single-ended output signal. The receiver circuit includes first and second comparators that receive the differential input signal and generate respective first and second differential output signals. A current summer is connected to the first and second comparators and receives the first and second differential output signals and generates a third differential output signal. A differential to single-ended converter is connected to the current summer and receives the third differential output signal and generates the single-ended output signal. The differential input signal varies from a ground voltage level to an external reference voltage level (VUSB), while the first and second comparators are made with devices that operate at an internal reference voltage level that is lower than the external reference voltage level.

Abstract: Implementing maintenance of a higher speed with fewest possible additional circuits while suppressing deterioration in characteristics of a clock buffer caused by an offset voltage. In a clock buffer circuit comprising a differential amplifier including a pair of load resistances, a pair of differential stage transistors, a constant current source transistor for supplying an operating current to the differential stage transistors, and a bias circuit for supplying to the constant current source transistor a bias voltage according to the resistance value of the load resistances, the bias circuit generates the bias voltage so controlled that the voltage gain of the clock buffer circuit becomes a predetermined value with respect to a variation of the resistance value of the load resistances.

Abstract: Methods and systems for reducing parasitic capacitance of a buffer for an electric circuit are disclosed herein. Aspects of the method may comprise coupling a gate of a first transistor to a first differential input of the buffer and coupling a gate of a second transistor to a second differential input of the buffer. The first and second transistors may be biased by a common mode output of a direct current (DC) voltage source for the buffer, where the common mode output of the DC voltage source may be coupled to the gate of the first transistor and the gate of the second transistor. The first transistor and the second transistor may comprise NMOS transistors and/or PMOS transistors. The DC voltage source may comprise a PMOS transistor and/or an NMOS transistor.

Abstract: A semiconductor integrated circuit has: a differential amplifier circuit including a first MOS transistor connected between a first node and a common node and a second MOS transistor connected between a second node and the common node; a first current supply circuit configured to supply current to the first node; and a second current supply circuit configured to supply current to the second node. A current supply ability of the first current supply circuit is variable.

Abstract: A self DC-bias high frequency logic gate is disclosed. The logic gate comprises at least one input terminal and one output terminal for performing Boolean operation on the high frequency input signals. The logic gate is characterized in that each transistor is coupled to an impedance matching network. The impedance matching network comprises a first terminal and a second terminal. Wherein, the first terminal is coupled to a gate of the transistor, and the second terminal is coupled to a drain of the transistor for providing an operation voltage to the transistor. When a gate of an N-type transistor and a gate of a P-type transistor are coupled with each other, and a drain of the N-type transistor and a drain of the P-type transistor are also coupled with each other, a common impedance matching network is shared with both the N-type transistor and the P-type transistor.

Abstract: A PAM-4 data slicer includes first, second, and third comparators which provide first, second, and third thresholds, respectively. Each of the comparators has an offset. The first and third comparators have an offset generating arrangement at their outputs to provide the first and third comparator circuits with symmetrical offsets.

Abstract: An operational amplifier includes: a differential amplifier for differentially amplifying first and second differential input signals to generate first and second output signals through first and second nodes; a driver for driving an output node in response to the second output signal; and a drive current adjuster for adjusting a driving current of the driver in response to the first output signal.

Abstract: A DC offset cancellation circuit that is capable of canceling a DC offset voltage occurring between a pair of differential output signals of a differential amplification circuit, while preventing a signal waveform from being distorted due to accumulation of AC components and a photo-electric pulse conversion circuit that is capable of generating an electrical pulse signal that accurately reproduces a rise timing and a fall timing of an optical pulse signal by canceling the DC offset voltage are provided. A photo-electric pulse conversion circuit is provided with a photodiode, an I-V conversion circuit, a first differential amplification circuit having a DC offset cancellation circuit, a second differential amplification circuit, a reference voltage generation circuit, and a comparison circuit.

Abstract: A power amplifier circuit comprising first and second modules, a current source and a push-pull module. The push-pull module comprises two intermediate transistors and two output transistors. The circuit also comprises third and fourth modules, operating in current mirror mode. Inputs of the third module are respectively connected to one main electrode of one of the intermediate transistors and to a node internal to the first module. Outputs of the fourth module are respectively connected to a main electrode of the other intermediate transistor and to a node internal to the second module. The circuit is designed to form a power output stage of an operational amplifier.

Abstract: The present technique relates to a method and apparatus for operating a differential buffer. In the differential buffer, a first stage may include a differential pair configured to receive input signals and generate output signals. The first stage may also include adjustment circuitry coupled to the differential pair and configured to adjust an amount of current dissipated by the differential buffer. Further, a second stage may include current pulse circuitry coupled to the differential pair and the adjustment circuitry, wherein the current pulse circuitry is configured to generate a current pulse that is coincident with the switching of the differential pair. Finally, the second stage may also include grounding circuitry coupled to the current pulse circuitry and the differential pair, wherein the grounding circuitry is configured to receive the current pulse to prevent the output signals from switching during a transition of the output signals.

Abstract: An differential LNA has first and second input MOS transistors, with differential inputs applied to their respective control gates and differential outputs taken at their respective drains. The gate-to-drain, Cgd, feedback capacitances of the first and second input MOS transistors are neutralized by respective gate-to-source, Cgs, capacitances in the two neutralizing MOS transistors. A first neutralizing MOS transistor has its control gate coupled to the control gate of the first input MOS transistor, its source node coupled to the drain node of the second input MOS transistor, and its drain node coupled to a fixed potential. A second neutralizing MOS transistor has its control gate coupled to the control gate of the second input MOS transistor, its source node coupled to the drain node of the first input MOS transistor, and its drain node coupled to the same fixed potential.

Abstract: Current feedback amplifiers circuits that generate common mode (CM) and/or differential mode (DM) currents are provided herein. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures and the claims.

Abstract: An integrated differential receiver includes a single gate oxide differential receiver and an associated switchable voltage supply circuit. The integrated differential receiver determines the desired receiver supply voltage and selects a supply voltage for the single gate oxide differential receiver. When a lower supply voltage is determined as the desired supply voltage, the integrated differential receiver automatically provides a supply voltage to the single gate oxide differential receiver with a voltage higher than the I/O pad supply voltage and higher than the maximum input signal voltage to increase the speed of operation for the differential receiver. The switchable voltage supply circuit is operatively responsive to a control signal which indicates the desired supply voltage for the I/O pad. In one embodiment, both the single gate oxide differential receiver and the switchable voltage supply circuit are single gate oxide circuits.

Abstract: A low-current input buffer is disclosed. The buffer uses self-biased N and P channel differential pairs with their outputs tied together. The self-biasing assists in reducing current consumption. The combination of N and P-channel differential pairs results in symmetry across a wide range of reference and supply voltages.

Abstract: A differential pair of transistors includes a first transistor and a second transistor having their sources coupled together. Their sources are further coupled to ground via a pull-down network. A single-ended output is coupled to the drain of the second of the pair of differential transistors. A differential current adjust circuit is coupled to a drain of the first of the pair of differential transistors, and the current adjust circuit is configured so that the second side of the differential output driver circuit conducts approximately the same current as the first side of the differential output driver circuit.

Abstract: A comparator circuit having improved operational characteristics. A predetermined voltage drop device is provided, such as an exemplary embodiment Schottky diode, having an anode connected to circuit power supply voltage and an output stage of the comparator and a cathode connected to an input stage of the comparator. The predetermined voltage drop device effects a lowering of the power supply voltage for the output stage bias between said power supply voltage and said common voltage. This reduces the required swing of the output stage drivers during a comparator input signal transition and reduces propagation delay of said comparator.

Abstract: A first field effect transistor receives an unbalanced signal from an input terminal at the gate thereof, and outputs a balanced signal from the drain thereof. A second field effect transistor has the gate thereof connected to the drain of the first field effect transistor and outputs a balanced signal from the drain thereof. The sources of the first field effect transistor and the second field effect transistor are connected to the drain of a third field effect transistor serving as a current source. The drain of the second field effect transistor is connected to the gate of the first field effect transistor via a first resistor. A first output terminal is connected between the drain of the first field effect transistor and the first resistor, and a second output terminal is connected between the drain of the second field effect transistor and a second resistor.

Abstract: A method and apparatus is provided for use in power amplifiers for reducing the peak voltage that transistors are subjected to. A power amplifier is provided with first and second switching devices and an inductor connected between the switching devices. The switching devices are driven such that the switching devices are turned on and off during the same time intervals.

Abstract: A system and method is provided for extending the range of a common mode voltage of a differential comparator. In one embodiment, a differential comparator comprises an input stage with a negative voltage reference node, a first differential input coupled to a first differential pair transistor and operative to receive a first input signal, and a second differential input coupled to a second differential pair transistor and operative to receive a second input signal. The first input signal and the second input signal form a differential input signal. The differential comparator further comprises a common mode sensing circuit interconnected between the first differential input, the second differential input, and the negative voltage reference node. The common mode sensing circuit is operative to sense a common mode voltage of the differential input signal and set a voltage potential at the negative voltage reference node substantially equal to the sensed common mode voltage.

Abstract: Circuitry including a BGREF (bandgap voltage reference) comparator including a plurality of MOS transistors that compare a resistor divided supply voltage to a function of at least two process parameter voltages.

Abstract: An apparatus for use with a sensor includes first and second signal treating circuit segments coupled with the sensor for presenting a substantially balanced differential signaling representation of output signals from the sensor. Each respective signal treating circuit segment comprises a plurality of circuit elements having different electrical symmetries coupled in parallel and establishing a plurality of parallel signal paths having asymmetric signal handling characteristics. A feedback circuit is coupled with the first and second signal treating circuit segments and provides feedback signals to selected circuit elements in each of the first and second signal treating circuit segments. The feedback signals effect substantially balanced signal handling among the selected circuit elements having similar electrical symmetries.

Abstract: An operational amplifier input stage provides a symmetrical rail-to-rail input common-mode voltage without turning off either pair of complementary differential input transistors. Secondary, or surrogate, transistor pairs assume the function of the complementary differential transistors. The circuit also maintains essentially constant transconductance, constant slew rate, and constant signal-path supply current as it provides rail-to-rail operation.

Abstract: Provided is an amplifier circuit having a constant output swing range and a stable delay time, where the amplifier circuit includes a first bias unit, a second bias unit, a comparison unit, and an amplifier unit, and the first bias unit responds to an internal reference signal with a predetermined voltage level and maintains constant the amount of a first current, and the second bias unit receives an external reference signal, responds to a control voltage, and controls the amount of a second current to be the same as the amount of the first current, and the comparison unit compares a voltage level of a first node with a voltage level of a second node, and controls a voltage level of the control voltage according to the comparison result, and the amplifier unit compares a voltage level of an external input signal with a voltage level of the external reference signal, amplifies and outputs a voltage difference between the two compared signals, responds to the control voltage, and controls the amount of a third

Abstract: A constant voltage outputting apparatus includes a differential amplifier circuit, an amplifier circuit, a current adjustment device and a stabilization circuit. The differential amplifier circuit performs a differential amplifying operation and outputs a differential amplified voltage. The amplifier circuit amplifies the differential amplified voltage output from the differential amplifier circuit. The current adjustment device adjusts a current characteristic of the amplifier circuit. The stabilization circuit stabilizes a state of the current adjustment device. A constant voltage outputting method is also described.

Abstract: A driving circuit for driving a capacitive load promptly to a target voltage is to have a broad dynamic range and achieve a high accuracy output and saving in the surface area with low power dissipation. A first period and a second period are provided in one data driving period. During the first period, a transistor amplifier for driving the load for charging, with a setting drive voltage (V1), and a transistor amplifier for driving the load for discharging, with a setting drive voltage (V2), with V1<V2, are both enabled for actuation and, during the second period, the transistor amplifier performing either the driving for charging or the driving for discharging, and a constant current source, performing the reverse of the operation of the transistor amplifier, are actuated, for driving the load to the target voltage.

Abstract: A complementary metal oxide semiconductor (CMOS) voltage regulator for low headroom applications includes a differential input common mode range amplifier. The differential input common mode range amplifier is formed by a plurality of CMOS transistors. A source follower CMOS transistor is coupled to an output of the differential input common mode range amplifier for providing an output of the CMOS voltage regulator. A current source is coupled to the differential input common mode range amplifier for maintaining a bias current through the differential input common mode range amplifier.

Abstract: An electronic circuit includes at least one differential pair of transistors, a control transistor switch, a first current source and a second current source. The second current source is connected to a common emitter node of the pair of transistors in order to accelerate the discharge of parasitic capacitances during a switching operation.

Abstract: According to one example embodiment, a buffer, e.g., in a clock/signal distribution apparatus is provided that substantially reduces jitter due to power supply noise. Decoupler and input stage isolates load from the top rail power supply (VDD). In a more particular embodiment, jitter contributions from the bottom rail power supply (VSS) can be minimized by cross-coupled load devices within load. Substantial independence from process and temperature is facilitated through the use of current bias, such as Proportional to Absolute Temperature (PTAT) current bias.

Abstract: Amplifier circuits that generate CM currents are provided. Amplifier circuits that generator DM currents are also provided. Fully differential current feedback amplifier circuits with separate CM and DM inputs are also provided. Such amplifier circuits combine the benefits of CFA designs, such as high slew rate and bandwidth, with independent control of DM and CM signals. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures and the claims.

Abstract: Amplifier circuits that generate CM currents are provided. Amplifier circuits that generator DM currents are also provided. Fully differential current feedback amplifier circuits with separate CM and DM inputs are also provided. Such amplifier circuits combine the benefits of CFA designs, such as high slew rate and bandwidth, with independent control of DM and CM signals. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures and the claims.

Abstract: A voltage monitor circuit for biasing a well region of a CMOS circuit includes a self-biased comparator which compares first (INP) and second (INN) input signals. The comparator includes first (MN1) and second (MN2) N-channel transistors with grounded sources, a drain of the first N-channel transistor and a gate of the second N-channel transistor being coupled to a first output (OUTN), and a drain of the second N-channel transistor and a gate of the first N-channel transistor being coupled to a second output (OUTP). First (MP1) and second (MP2) P-channel transistors are operated to couple the second or first input signal to the second or first output, respectively, by controlling the gate-to-source voltage of the first or second P-channel transistor according to the polarity of a voltage difference between the first and second input signals.

Abstract: The input stage of the fully differential amplifier output stage is configured in a differential pair configuration with a tail current. The tail current is divided between two legs of the input stage and is higher in the leg that has the higher of the two input voltage levels (in or inb). The devices in each leg of the fully differential amplifier output stage may be cascoded to avoid electrical voltage overstress. The top device in each leg of the differential input stage may be coupled in a diode configuration and is utilized to mirror the current into another NMOS current mirror as well as to a PMOS output device. The gate of the PMOS output devices are connected in a cross-coupled configuration. The NMOS current mirrors are utilized to mirror the current into the NMOS output devices in a non-cross-coupled configuration.

Abstract: Amplifier circuits that generate CM currents are provided. Amplifier circuits that generator DM currents are also provided. Fully differential current feedback amplifier circuits with separate CM and DM inputs are also provided. Such amplifier circuits combine the benefits of CFA designs, such as high slew rate and bandwidth, with independent control of DM and CM signals. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures and the claims.

Abstract: Disclosed is a data detector for detecting data placed on a bi-directional data channel having two nodes. The data on the data channel is a combination of data placed on the data channel at both nodes. The data detector at the first node compares data received from the data channel to multiple reference voltages. Which reference voltages are used for comparison is determined by the state of data placed on the data channel at the first node. By comparing the data from the data channel to more than one reference voltage data can be detected with a swing margin of about 50%, such that it is less affected by noise, power or other glitches than are conventional circuits. Methods of detecting data are also disclosed.

Abstract: Provided is a transconductor circuit for compensating distortion of an output current. The transconductor circuit is a differential pair with source degeneration and includes a main circuitry to which a predetermined input voltage is applied, constant current sources which supply the main circuitry with constant bias, an auxiliary circuitry which is connected to nodes of the main circuitry to compensate the distortion of the output current, and a variable current source which controls a depth or degree of a distortion compensation operation for the output current.

Abstract: A data driving circuit includes a driver in which a driving current is controlled in response to predetermined bits of digital control signal and which receives a differential input data signal to generate differential output data signal; and a digital control signal generator for storing and generating the digital control signal. The driver includes a pre-driver for passing a pre driving current in response to a bias voltage and for receiving the differential input data signal(s) to generate first and second signals; and a main driver in which a main driving current is controlled in response to the digital control signal and which generates the differential output data signals in response to the first and second signals.