Abstract: An operational amplifier-based hysteresis comparator and a chip are provided. The hysteresis comparator includes: an input stage and an amplification stage. The input stage includes: a first input branch and a second input branch, where the first input branch generates a first current based on the first voltage, and the second input branch generates a second current based on the second voltage. The first current is connected with a first input terminal of the amplification stage, and the second current is connected with a second input terminal of the amplification stage. An output terminal of the amplification stage outputs a first level when the first current is greater than the second current, and outputs a second level when the first current is less than the second current. The present disclosure changes the hysteresis voltage generation mode, thereby reducing the instability caused by positive feedback.

Abstract: A receiver detection system includes a media access control (MAC) circuit, a common-mode voltage detector, and a receiver detector. The common-mode voltage detector is configured to detect whether a common-mode voltage satisfies a voltage condition, and to send a ready signal to the receiver detector after the common-mode voltage satisfies the voltage condition. The receiver detector is configured to start a detection process according to the ready signal and a detection start signal from the MAC circuit. In the detection process, the receiver detector sends out a detection signal for detecting whether a receiver exists, and then outputs a detection result to the MAC circuit, wherein the detection result indicates whether the receiver exists. The receiver detection system can prevent the receiver detector from starting the detection process before the common-mode voltage satisfies the voltage condition.

Abstract: A fast signal response circuit with hysteresis control includes a switch element and a comparator. The switch element includes a first and a second input terminals and a control terminal, the first terminal is configured to receive a first reference signal, the second terminal is configured to receive a second reference signal, the control terminal is configured to receive a control signal, and the switch element is configured to output the first or the second reference signal through a first output terminal according to the control signal. The comparator includes a third input terminal, a fourth input terminal and a second output terminal, the third input terminal is connected to the first output terminal, the fourth input terminal is configured to receive a sensing signal corresponding to a light input, and the second output terminal is connected to the controller and is configured to output the comparison result.

Abstract: The present disclosure provides a comparator and a decision feedback equalization circuit. The comparator includes: a first sampling circuit configured to generate, under the control of a first control signal and a clock signal, first differential signals according to a signal to be compared and a first reference signal; a first positive feedback circuit configured to accelerate a difference between the first differential signals; a second sampling circuit configured to generate, under the control of a second control signal and the clock signal, second differential signals according to the signal to be compared and a second reference signal, where the first reference signal is larger than the second reference signal; a second positive feedback circuit configured to accelerate a difference between the second differential signals.

Abstract: The invention provides a full swing voltage conversion circuit. The full swing voltage conversion circuit comprises: an input terminal for inputting a first level signal; an output terminal for outputting a second level signal; a differential input unit for inverting the first level signal of the input terminal, and outputting a differential input signal; a conversion unit; and an output driving unit; wherein the full swing voltage conversion circuit further comprises an auxiliary pull-down unit between the input terminal and the conversion unit for receiving a feedback to improve capability of the conversion unit in recognizing the differential input signal, such that the full swing voltage conversion circuit of the invention can convert from inputting a low voltage to outputting a high voltage.

Abstract: Voltage-to-current converters that include two current mirrors are disclosed. In an example voltage-to-current converter each current mirror is a complementary current mirror in that one of its input and output transistors is a P-type transistor and the other one is an N-type transistor. Such voltage-to-current converters may be implemented using bipolar technology, CMOS technology, or a combination of bipolar and CMOS technologies, and may be made sufficiently compact and accurate while operating at sufficiently low voltages and consuming limited power.

Abstract: In certain aspects, a regenerative stage of a sense amplifier includes a first inverter having an input and an output, and a second inverter having an input and an output. The regenerative stage also includes a third inverter having an input, an output coupled to the input of the second inverter, a first supply terminal coupled to a supply rail, and a second supply terminal coupled to the output of the first inverter. The regenerative stage further includes a fourth inverter having an input, an output coupled to the input of the first inverter, a first supply terminal coupled to the supply rail, and a second supply terminal coupled to the output of the second inverter.

Abstract: A background offset drift calibration circuit and method for comparator are proposed. The background calibration circuit and method are designed based on the approximate linear characteristic of the offset drift of a comparator caused by the variation of temperature and power supply. The calibration circuit for the comparators obtains the offset drift characteristic of each comparator by performing twice foreground calibration and selects the comparator with the largest drift as the reference comparator and other comparators as working comparators. The reference comparator is configured to track the offset drift and trigger the background calibration circuit of other working comparators. The working comparators compensate for the offset drift caused by the temperature or the power supply in the background by linear interpolation based on the offset drift characteristic of each comparator.

Abstract: A system includes: a power supply; an adaptively biased power event detection comparator; and an adaptive bias circuit for the adaptively biased power event detection comparator. The adaptively biased power event detection comparator is configured to compare a first input corresponding to a voltage level of the power supply with a second input corresponding to a reference voltage. The adaptive bias circuit is configured to increase a bias current for the adaptively biased power event detection comparator based on the voltage level of the power supply decreasing to be closer to the reference voltage.

Abstract: A light source device includes: an excitation light source unit that emits excitation light; a phosphor wheel unit that includes a wheel that produces fluorescence by the excitation light and that, by causing the wheel to rotate, changes the position on the wheel that is irradiated by the excitation light; a detection unit that detects rotation of the wheel; and a control unit that changes intensity of the excitation light on the basis of the detection result of the detection unit and the fluorescence characteristic of the wheel.

Abstract: A sensor interface includes on-chip relaxation oscillator circuit and a PLL that operate cooperatively to generate a highly accurate clock signal on-chip using low-power components. A photodiode generates a current signal based on an optical signal that is representative of a sensor signal. An ADC that operates based on the highly accurate clock signal generates a digital signal based on the current signal generated by the photodiode, and a processor processed the digital signal to estimate sensor data within the sensor signal. Examples of characteristics that may be sensed can include environmental characteristics (e.g., temperature, humidity, barometric pressure, etc.) and/or biomedical characteristics (e.g., body temperature, heart rate, respiratory rate, blood pressure, etc.). If desired, an amplifier processes the photodiode-provided current signal before it is provided to the ADC. Also, one or more CDACs that generate feedback currents may be used to reduce noise sensitivity of the sensor interface.

Abstract: Embodiments of the invention relate to an input-powered comparator. Embodiments of the invention also pertain to an active diode that includes an input-powered comparator and a switch. In a specific embodiment, the input-powered comparator only consumes power when an input source provides sufficiently high voltage. Embodiments of the active diode can be used in an energy harvesting system. The comparator can be powered by the input and the system can be configured such that the comparator only consumes power when the input is ready to provide power to the load or energy storage element. In a specific embodiment, when there is no input, or the input is too low for harvesting, the comparator does not draw any power from the energy storage element (e.g., battery or capacitor) of the system.

Abstract: An apparatus includes a voltage monitoring device to generate a brownout indication signal in response to a change in a power supply voltage. The apparatus also includes a mode control device to control a temporal response of the voltage monitoring device to the change in the power supply voltage based, at least in part, on a voltage level of the power supply voltage.

Abstract: A circuit to a extend signal comparison voltage range includes a latching circuit and a comparator responsive to common-mode input signals. The comparator is coupled to the latching circuit and to a dynamic node. The circuit also includes a clocked boost circuit coupled to the dynamic node. The clocked boost circuit is configured to extend a supply voltage range of the comparator via biasing the dynamic node. A method to extend a signal comparison voltage range includes selectively shifting a voltage level of one of a ground reference of a dynamic circuit or a supply reference of the dynamic circuit in response to a clock signal.

Abstract: A power-on reset circuit includes a first-conductive-type MOS transistor having a first source connected to a first power supply, a first drain, and a first gate connected to a second power supply; a second-conductive-type MOS transistor having a second source connected to the second power supply, a second drain connected to the first drain, and a second gate, to which a bias potential which depends on neither a potential of the first power supply nor a potential of the second power supply is applied; and an output node for outputting a reset signal corresponding to a potential of the first drain, in a process that a voltage between the first power supply and the second power supply increases.

Abstract: A power module including a power device and a periphery circuit configured to suppress a leakage current in the power device. The periphery circuit includes a leakage current detection circuit configured to detect a leakage current from the power device and control operation of the power device based on a result of the detection. The leakage current detection circuit including an input terminal connected to the power device, a plurality of NMOS transistors, a plurality of PMOS transistors connected to the plurality of NMOS transistors, and a comparator.

Abstract: A driver having low power consumption includes a first input terminal, a second input terminal, an output terminal, a power supply terminal, a ground terminal, a driving circuit, an adjusting circuit connected to the driving circuit and a biasing circuit which is connected to the driving circuit and the adjusting circuit. A method for accomplishing low power consumption of a driver is also provided. The method accomplishes an object of low power consumption by dynamically adjusting a driving current of a driver according to a difference between inputted differential signals.

Abstract: Sense amplifiers including bias circuits are described. Examples include bias circuits having an adjustable width transistor. A loop gain of the bias circuit may be determined in part by the adjustable width of the transistor. Examples of sense amplifiers including amplifier stages configured to bias an input/output node to a reference voltage.

Abstract: A method and circuit for attenuating positive feedback in a comparator in one embodiment includes an amplifier configured to compare a first input signal with a second input signal and to provide an output based upon the comparison, a non-linear function with a first input operably connected to an output of the amplifier, and a feedback loop operably connected to the output of the non-linear function and to a second input of the non-linear function, the feedback loop including a feedback limiting circuit configured to attenuate a feedback signal to the second input of the non-linear function.

Abstract: A buffer and control circuit for a synchronous memory controller includes first and second differential comparators and control logic. The first differential comparator is provided with positive and negative differential input signals and the second differential comparator is provided with offset positive and negative differential input signals. The first and second differential comparators generate output signals based on magnitudes of the positive and negative differential input signals and the offset positive and negative differential input signals. The control logic generates a reference strobe signal based on the output signals.

Abstract: A comparator to provide an output voltage indicative of comparing an input voltage with a reference voltage, where the comparator has an asymmetric frequency response. With an asymmetric frequency response, the bandwidth of the input voltage may be greater than the bandwidth of the reference voltage. A comparator includes a differential pair of transistors coupled to a current mirror and biased by a current source, where in one embodiment, a capacitor shunts the sources of the differential pair. In a second embodiment, a capacitor couples the input voltage port to the gates of the current mirror transistors. In a third embodiment, the comparator utilizes both capacitors of the first and second embodiments.

Abstract: A relaxation oscillator has a comparator that includes first through third bias current transistors coupled to a first supply rail. First and second input transistors form a pair of parallel coupled transistors connected to the first bias current transistor. A first current mirror control transistor connects the first input transistor to a second supply rail. A first current mirror output transistor is coupled to the first current mirror control transistor, and connects the second bias current transistor to the second supply rail. A second current mirror control transistor connects the second input transistor to the second supply rail. A second current mirror output transistor is coupled to the second current mirror control transistor, and connects the third bias current transistor to the second supply rail. A transition time reduction transistor, coupled across the third bias current transistor, is coupled to the second bias current transistor, and provides a comparator output.

Abstract: A high-speed differential comparator circuit is provided with an accurately adjustable threshold voltage. Differential reference voltage signals are provided to control the threshold voltage of the comparator. The common mode voltage of the reference signals preferably tracks the common mode voltage of the differential high-speed serial data signal being processed by the comparator circuit.

Abstract: This document discusses, among other things, apparatus and methods for controlling a hysteresis range of a voltage comparator. In an example, an apparatus can include an amplifier having a temperature dependency, a comparator configured to receive first and second currents and to provide an output voltage indicative of a hysteretic comparison of the first and second input voltages, wherein a range of hysteresis of the apparatus is controlled over a range of temperatures. In an example, the amplifier can be configured to receive first and second input voltages and to provide the first and second currents.

Abstract: A semiconductor device configured that its differential pair is made operable in both states of high speed with a high consumption current and low speed with a low consumption current. A differential circuit includes differential pair transistors and a tail current source for supplying a tail current that is switchable so that an amount of current flowing in the differential pair transistors may be switched between at least two sates of different levels. The differential pair transistors have a characteristic that, with a decrease of currents flowing in the differential pair transistors, a value of ?(?I/gm) decreases monotonously, where ? denotes a standard deviation, ?I denotes a difference of the amounts of current of the differential pair transistors, and gm denotes transconductance of the differential pair transistors.

Abstract: A comparator is disclosed. The comparator includes a mirror circuit that is electrically coupled to a first voltage source and a second voltage source. The first voltage source produces a first voltage and the second voltage source produces a second voltage. The comparator also includes a first positive metal oxide semiconductor (PMOS) transistor electrically coupled to the first voltage source and an output terminal. The first PMOS transistor is biased by the mirror circuit. The comparator also includes a first negative metal oxide semiconductor (NMOS) that is electrically coupled to a ground terminal and the output terminal. The first NMOS transistor is also biased by the mirror circuit. An electrical current flowing across the first NMOS transistor is mirrored from an electrical current flowing through the first PMOS transistor. A method to operate the comparator and a comparator system is also disclosed.

Abstract: A squelch detection circuit for high-speed serial communication includes: an input level shifter configured to receive signals inputted through signal lines and shift the received signals to a predetermined potential level; a comparator configured to receive signals outputted from the input level shifter, and compares the received signals to determine whether data signals are noise or signal components; and a reset signal generator configured to receive the signals outputted from the input level shifter, convert the received signals into a single signal, and then generate a reset signal for an elastic buffer. The squelch detection circuit may detect a squelch state and provide a reset value for an elastic buffer in a USB 2.0 interface, and may reduce power consumption as much as possible in a suspend mode.

Abstract: A buffer for converting sinusoidal waves to square waves with reduced phase noise is described herein. The buffer shunts current from the outputs of a differential amplifier during sinusoidal state transition periods at the differential amplifier inputs to increase the finite slope of square wave transition periods of the output square wave. More particularly, a sinusoidal wave having alternating peaks and valleys connected by sinusoidal state transition periods is applied to differential inputs of a differential amplifier to generate a square wave at the differential outputs, where the output square wave comprises alternating high and low states connected by square wave state transition periods having a finite slope. The output square wave is shaped to increase the finite slope of the square wave transition periods by providing additional paths between the differential outputs and ground that shunt current from the differential amplifier during the sinusoidal state transition periods.

Abstract: A method and circuit for attenuating positive feedback in a comparator in one embodiment includes an amplifier configured to compare a first input signal with a second input signal and to provide an output based upon the comparison, a non-linear function with a first input operably connected to an output of the amplifier, and a feedback loop operably connected to the output of the non-linear function and to a second input of the non-linear function, the feedback loop including a feedback limiting circuit configured to attenuate a feedback signal to the second input of the non-linear function.

Abstract: Differential signal detection circuitry with an integrated reference voltage. The reference voltage is added as an offset to the output voltage, and its integration ensures that variations in the reference voltage closely track variations in the signal. Accordingly, the detection threshold for the signal being detected remains more consistent over variations in the circuit manufacturing process, power supply voltage and operating temperature.

Abstract: A digital linear transmitter for digital to analog conversion of a radio frequency signal. The transmitter includes a delta sigma (??) digital to analog converter (DAC) and a weighted signal digital to analog converter in the transmit path of a wireless device to reduce reliance on relatively large analog components. The ?? DAC converts the lowest significant bits of the oversampled signal while the weighted signal digital to analog converter converts the highest significant bits of the oversampled signal. The transmitter core includes components for providing an oversampled modulated digital signal which is then subjected to first order filtering of the oversampled signal prior to generating a corresponding analog signal. The apparatus and method reduces analog components and increases digital components in transmitter core architecture of wireless RF devices.

Abstract: A comparator includes: a wide-swing operation transconductance amplifier (OTA), having first and second differential input pairs for receiving first and second differential input signals respectively, the wide-swing OTA generating first and second intermediate output voltages in comparing the first with the second differential input signals; a current switch group; a current mirror group, wherein when an input common mode voltage of the first and the second differential input signal tends to one of a first and a second reference voltage, one of the first and the second differential input pair is turned off, and the current switch group and the current mirror group compensate a current flowing through the other of the first and the second differential input pair; and a decision circuit coupled to the wide-swing OTA, for enlarging a voltage difference between the first and the second intermediate output voltage to output a voltage comparison output signal.

Abstract: A comparator includes: a pre-amplification module, configured to generate two amplified differential signal reference currents according to an input voltage and a reference voltage; and a differential signal obtaining module, configured to obtain a differential signal according to the two amplified differential signal reference currents. The pre-amplification module includes a differential unit, an offset unit, and an amplification unit, where the differential unit is configured to generate two direct current bias currents according to the input voltage and the reference voltage; the offset unit is configured to generate an offset current of the two direct current bias currents according to the input voltage and the reference voltage, so as to reduce magnitude of the two direct current bias currents and obtain two differential signal reference currents; the amplification unit is configured to receive the two differential signal reference currents, and amplify the two differential signal reference currents.

Abstract: A verification system for verifying an integrated circuit design is provided. The verification system includes a functional block finding module configured to identify potential sensitive circuits in the integrated circuit design; and a search module. The search module is configured to find sensitive circuits from the potential sensitive circuits; and verify the sensitive circuits.

Abstract: A comparator comprises a current mirror, a differential input pair, and a auxiliary circuit. The current mirror has a biasing end coupled to a power voltage, a first end, and a current outputting end coupled to an output node of the comparator. The differential input pair has a first and second input ends for respectively receiving a first voltage and a second voltage, a second and third ends, and a ground end, wherein the third end is coupled to the first end. The auxiliary circuit is coupled between the output node and the second end, and provides a minimum voltage of a comparison result output at the output node. The comparison result is the power voltage when the first voltage is larger than the second voltage, and the comparison result is the minimum voltage when the first voltage is less than the second voltage.

Abstract: An integrated circuit comparator comprises a differential amplifier, a source follower circuit coupled to a gate terminal of a first transistor in the differential amplifier, and an output circuit. One or more source follower circuits may be utilized in connection with the differential amplifier, and one or more source follower circuits may be utilized in connection with the output circuit.

Abstract: The present invention is directed for a comparator circuit used in an analog-to-digital converter, and more particularly, for a low power consumption low kick-back noise comparator circuit for an analog-to-digital converter, which can significantly reduce kick-back noise generated in a signal input stage due to a signal regeneration method employed in a signal comparing operation and can efficiently reduce power consumption.

Abstract: This document discusses, among other things, apparatus and methods for controlling a hysteresis range of a voltage comparator. In an example, an apparatus can include an amplifier having a temperature dependency, a comparator configured to receive first and second currents and to provide an output voltage indicative of a hysteretic comparison of the first and second input voltages, wherein a range of hysteresis of the apparatus is controlled over a range of temperatures. In an example, the amplifier can be configured to receive first and second input voltages and to provide the first and second currents.

Abstract: An output stage includes a first transistor pair with a first conductivity type and a second transistor pair with a second conductivity type. The source connections of the first and second transistors in the first transistor pair and of the first and second transistors in the second transistor pair are respectively connected to a first and a second circuit node. The output stage further includes a first current mirror with the first conductivity type and a second current mirror with the second conductivity type. The current mirror transistors are connected to the signal output. The signal input is connected to control connections of the first transistors in the first and second transistor pairs. A second connection of the second transistor in the first transistor pair is connected to the second current mirror, and a second connection of the second transistor in the second transistor pair is connected to the first current mirror.

Abstract: An input circuit is disclosed. The input circuit can include a cross voltage generating block that can be configured to perform charge-sharing on a pair of input signals whose phases are opposite to each other and generate a cross voltage, and an input buffer block that can be configured to buffer the pair of input signals at a voltage level corresponding to a voltage level of the cross voltage and generate an output signal.

Abstract: The invention discloses a method for tuning nano-scale analog-circuit designs in order to reduce random-device mismatches and optimize said design, where nano-scale devices potentially have large-scale process variations. The method includes providing a tunable circuit topology, wherein each nano-scale device comprises a single component or comprises multiple parallel components. Each component is decomposed into multiple discrete sub-components, wherein each said sub-component either operates in parallel with other like components to effectively operate like one bigger component. The sub-components are subjected to a dynamic-programming process to adaptively select the sub-components to be kept operational, while configuring the nonselected sub-components to be nonoperational, based on the measurement of at least one operational parameter.

Abstract: A comparator to provide an output voltage indicative of comparing an input voltage with a reference voltage, where the comparator has an asymmetric frequency response. With an asymmetric frequency response, the bandwidth of the input voltage may be greater than the bandwidth of the reference voltage. A comparator includes a differential pair of transistors coupled to a current mirror and biased by a current source, where in one embodiment, a capacitor shunts the sources of the differential pair. In a second embodiment, a capacitor couples the input voltage port to the gates of the current mirror transistors. In a third embodiment, the comparator utilizes both capacitors of the first and second embodiments.

Abstract: A hysteretic comparator is proposed for comparing input signals and producing an output signal VOT with a hysteresis window Vhys. The hysteretic comparator includes a differential input stage with current output (DICO) having input transistors with transconductance Gmtnx for converting the input signals, with an input stage transconductance Gmin, into intermediate signal currents. A steerable offset current generator, driven by a steering control signal, steers an offset current source IOS to alternative offset currents. A current-to-voltage summing converter (IVSC) sums up the intermediate signal currents and the offset currents and converts the result into VOT plus the steering control signal causing Vhys=IOS/Gmin. A feedback resistance RNF is connected to the input transistors to form a negative feedback loop. The RNF is sized such that GMin, hence Vhys, becomes essentially solely dependent upon the feedback conductance GNF=1/RNF independent of the Gmtnx thus its process and environmental variation.

Abstract: A semiconductor device includes a reference voltage generating unit configured to produce a reference voltage by dividing a voltage difference between a positive clock terminal and a negative clock terminal, and a logic determination unit configured to determine a logic level of an external signal based on the reference voltage.

Abstract: A disclosed semiconductor device includes an input terminal, a power line, a pnp-bipolar transistor connected to the power line, a first resistor connecting an emitter of the transistor to the input terminal, a second resistor connecting a collector of the transistor to ground, an operation circuit operable when the input voltage is a predetermined voltage or higher, the predetermined voltage being set within a first voltage region in which the input voltage cannot turn on the transistor, a comparator comparing an internal voltage with a reference voltage, the internal voltage being changed from a voltage value in a non-conductive state in which the transistor is not turned on, and an output terminal configured to output an output voltage which changes in response to a result of comparing the internal voltage with the reference voltage.

Abstract: An envelope detecting circuit is provided. The envelope detecting circuit comprises a source degeneration circuit that amplifies an input differential signal, a differential gain stage that supplies a voltage proportional to the amplified signal, a potential hold circuit that holds the voltage supplied from the gain stage, a comparator circuit that compares the voltage held by the potential holding circuit with a reference potential to output a detect signal, and envelope level adjustment and selection unit that responds to the detect signal and outputs a control signal to the source degeneration circuit.

Abstract: An integrated circuit comparator comprises a differential amplifier, a source follower circuit coupled to a gate terminal of a first transistor in the differential amplifier, and an output circuit. One or more source follower circuits may be utilized in connection with the differential amplifier, and one or more source follower circuits may be utilized in connection with the output circuit.

Abstract: A comparator module applied to a voltage level clamping circuit which can be implemented in an integrated circuit (IC) is provided. The IC includes a parasitic diode coupled between a first voltage source and a second voltage source. The voltage level clamping circuit includes a switch module and a comparator module. The comparator module has an output terminal, a first input terminal coupled to a first voltage source, and a second input terminal coupled to a second voltage source. The comparator module includes a current source module, a first voltage level adjusting circuit module, a second voltage level adjusting circuit module, and a comparing circuit module.

Abstract: An amplifying circuit of a semiconductor integrated circuit includes a data amplifier that outputs an up-signal and a down-signal amplified according to a comparison result between an up-data signal and a down-data signal in response to a control signal. The data amplifier repeats an operation of amplifying the up-signal and the down-signal according to the comparison result between the up-signal and the down-signal to be fed back to the data amplifier.

Abstract: A semiconductor device includes a reference voltage generating unit configured to produce a reference voltage by dividing a voltage difference between a positive clock terminal and a negative clock terminal, and a logic determination unit configured to determine a logic level of an external signal based on the reference voltage.