Abstract: Disclosed is a sample and hold circuit for detecting a parameter of a data signal, which includes: a first switching module, wherein the sample and hold circuit samples the data signal according to the turning on or off of the first switching module; at least one capacitor, coupled to the first switching module; a second switching module, coupled to the capacitor; a controllable reference voltage source, for providing a first reference voltage to charge/discharge the capacitor via the second switching module according to a control signal; a first comparator, coupled to the capacitor, for comparing a voltage drop on the capacitor and the first reference voltage to generate a first comparing result; and a control circuit, coupled to the controllable reference voltage source and the first comparator, for generating the control signal according to the comparing results.

Abstract: An approach that provides active pre-emphasis for a passive RC network is described. In one embodiment, there is a circuit that comprises an RC filter including a resistive divider formed from a first resistor and a second resistor and a filtering capacitor. The first resistor is configured to receive an input voltage and the second resistor and filtering capacitor are in parallel and configured to generate a reference voltage that is a percentage of the input voltage. An operational amplifier is coupled to the RC filter. A first multiplexer controlled by a pulse pre-emphasis signal is coupled to the operational amplifier and the RC filter. A second multiplexer controlled by a sample and hold clocking signal has inputs that are coupled to the first multiplexer and ground.

Abstract: A sample/hold circuit module. The sample/hold circuit module comprises a sample/hold circuit, an S/H controller, a pass transistor, and a high voltage generator. The sample/hold circuit comprises a capacitor and a sampling switch. The capacitor has a first electrode coupled to a first fixed voltage and a second electrode coupled to an output node of the sample/hold circuit module. The sampling switch comprises an output terminal coupled to the second electrode of the capacitor, an input terminal, and a control terminal. The S/H controller is coupled between the control terminal of the sampling switch and a second fixed voltage. The pass transistor has a sampling input terminal, an output terminal coupled to the input terminal of the sampling switch, and a control terminal. The high voltage generator is coupled between the control terminal of the pass transistor and the second fixed voltage.

Abstract: Variable phase bit sampling implementations are disclosed which minimize requirements for downstream digital processing resynchronization in systems that incorporate adjustable bit phase sampling that utilize variable delay elements which can interrupt the clocking stream signal. A sampling device includes a sampling circuit operative to provide an output signal in response to a data signal, where the sampling circuit includes a data input and a clock input. A variable delay circuit provides an adjustable trigger signal to the clock input in response to a first delay control signal. A fixed delay circuit delays the output signal by a predetermined amount of time in response to at least one delay control signal.

Abstract: A single-ended, non-differential switched capacitor circuit is disclosed which removes the effect of common mode noise. To this end, the circuit creates a capacitance divider using the sampling capacitors, Cs, to create a stable and noise-free common mode voltage (Vcom) signal. Once created, this Vcom signal is coupled across a large common mode capacitance, Ccom, which is preferably off chip, to further control its value. Thereafter, the voltage Vcom is preferably allowed to settle while the data is disconnected. In this way, the Vcom signal is not provided to the circuit, but instead is cleanly generated within the circuit itself when needed. Thereafter, the generated Vcom signal is paralleled with the integration capacitor, C1, to produce the non-differential output voltage Vout. Then, the sampling capacitors, Cs, are shorted to remove any charges stored on them and the process is repeated.

Abstract: A high accuracy sample and hold circuit including a first switch, a second switch, a first capacitor, a second capacitor and an amplifier is disclosed. The first capacitor receives and saves a sampling voltage from the first switch during a first period, while the second capacitor receives and saves another sampling voltage from the second switch during a second period. The amplifier has first and second positive input terminals, a negative input terminal, an output terminal and a first input stage and an output stage. Wherein, the first input stage includes a first input set and a second input set. During the first period, the amplifier disables the operation of the first input set and enables the operation of the second input set, while during the second period, the amplifier enables the operation of the first input set and disables the operation of the second input set.

Abstract: A sample-and-hold circuit including a first switch, a first capacitor and an amplifier is provided. The switch has a first terminal to receive the input signal and transmit it to a second terminal thereof in the sample period. The first terminal of the first capacitor couples to the second terminal of the first switch, and the second terminal of the first capacitor couples to a first voltage for storing the sampling result of the input signal. The amplifier couples to the second terminal of the first switch, wherein the amplifier is disabled in the sample period, and the amplifier is enabled to generate the output signal according to the sampling result in the hold period.

Abstract: A sample hold circuit includes an op-amp, first capacitors provided on an inverting side of the op-amp and second capacitors provided on a non-inverting side. The sample hold circuit is configured such that a total capacitance of the first and second capacitors to which an input voltage is applied in a sampling phase is equal to that of the first and second capacitors to which the input voltage is applied in a holding phase, a total capacitance of the first capacitors to which the input voltage is applied in the holding phase is equal to that of the second capacitors to which the input voltage is applied in the holding phase, and a total capacitance of the first capacitors to which the input voltage is applied in the sampling phase is different from that of the second capacitors to which the input voltage is applied in the sampling phase.

Abstract: An electronic device, such as a sample-and-hold circuit, includes a field effect transistor (FET), a capacitor, and a voltage offset circuit. The FET is configured to receive a signal at a first terminal thereof and selectively provide the signal to a second terminal thereof responsive to a switching signal at a gate terminal thereof. The capacitor is electrically connected to the second terminal of the FET. The voltage offset circuit is electrically connected to the first terminal and the gate terminal of the FET. The voltage offset circuit is configured to maintain a substantially constant voltage differential between the first terminal and the gate terminal of the FET while the signal is provided to the second terminal of the FET and substantially independent of a voltage level of an input signal. Related methods of operation are also discussed.

Abstract: A high accuracy sample and hold circuit including a first switch, a second switch, a first capacitor, a second capacitor and an amplifier is disclosed. The first capacitor receives and saves a sampling voltage from the first switch during a first period, while the second capacitor receives and saves another sampling voltage from the second switch during a second period. The amplifier has first and second positive input terminals, a negative input terminal, an output terminal and a first input stage and an output stage. Wherein, the first input stage includes a first input set and a second input set. During the first period, the amplifier disables the operation of the first input set and enables the operation of the second input set, while during the second period, the amplifier enables the operation of the first input set and disables the operation of the second input set.

Abstract: Gain control for delta sigma analog-to-digital converter. A method is disclosed for driving the input of an integrator in a delta-sigma converter having an amplifier with a non-inverting input, an output and a positive input connected to a reference voltage and an integration capacitor connected between the non-inverting input and the output. An input voltage is sampled at a first rate onto an input sampling capacitor and then charge is dumped from the input sampling capacitor to the non-inverting input of the amplifier at a second time and at the first rate. A reference voltage is sampled onto a feedback sampling capacitor at substantially the first rate, and charge stored on the feedback sampling capacitor is dumped to the non-inverting input of the amplifier at a second rate different than the first rate.

Abstract: A track and hold circuit (1) comprising:—a linear amplifier (2) receiving a differential analog signal (D+, D?) and being controlled by a first binary clock signal (H+) having a first phase,—the linear amplifier (2) providing a feed-forward input signal substantially equal with the differential analog signal (D+, D?) to a pseudo latch circuit (3) in the first phase of the first binary clock signal (H+), said pseudo latch circuit (3) being controlled by a second binary clock signal (H?) for memorizing the input signal and providing a differential output signal (LD+, LD?) substantially equal with the input signal during a second phase of the first binary clock signal (H?), the second binary clock signal being substantially in antiphase with the first binary clock signal (H+).

Abstract: A receiver to detect pulses on a home phone wiring network using envelope detection. The receiver comprises an integrating capacitor charged by a first current source responsive to a differential signal propagated on the wiring network, and discharged by a FET in combination with a second current source. The combination of the FET and the second current source allows the capacitor to be quickly discharged in a smooth fashion. An application of this receiver is for a PHY according to the Home Phoneline Networking Alliance.

Abstract: A switched capacitor buffer operating by the push-pull method is taught. The buffer may include a pull-up device and a pull-down device. A switched capacitor circuit may be used to control the pull-up device and the pull-down device to achieve accurate push-pull operation. According to some embodiments, the switched capacitor buffer displays an optimal combination of design simplicity, low power consumption and high-frequency response.

Abstract: A switched-capacitor circuit for sampling a pair of differential input signals includes a first bootstrapped switch and a first non-boosted switch connected in parallel between a first output terminal of an amplifier and a first feedback node of the switched-capacitor circuit to form a first feedback signal path and a second bootstrapped-switch and a second non-boosted switch connected in parallel between a second output terminal of the amplifier and a second feedback node of the switched-capacitor circuit to form a second feedback signal path. The first and second non-boosted switches are controlled by a first clock signal and the first and second bootstrapped switches are controlled by a second clock signal where the second clock signal is the first clock signal delayed by a predetermined amount.

Abstract: A sample-and-hold device including first and second capacitors, first and second switches, amplifier and feedback network is provided. The amplifier includes first and second input stages, output stage and switchable bias current source. The first switch and the first capacitor are coupled in series between input signal and first voltage, and a common node is coupled to a first positive input terminal of the amplifier. The first switch is on during first period and off during second period. The second switch and the second capacitor are coupled in series between the input signal and second voltage, and a common node is coupled to a second positive input terminal of the amplifier. The second switch is on during second period and off during first period. The switchable bias current source biases the second input stage during first period, and switches to bias the first input stage during second period.

Abstract: The invention relates to an active current mode sampling circuit comprising an operational amplifier (103) and at least one switched capacitor (C2, C2a, C2b). In order to reduce the power consumption of such a circuit, first switching elements (S101a, S101b, S102a, S102b) switch the switched capacitor (C2, C2a, C2b) between an input and an output of the operational amplifier (103) during charging phases ?1. Further, second switching elements (S103a, S103b, S104a, S104b) connect the switched capacitor (C2, C2a, C2b) during discharging phases ?2 to a subsequent stage (104), in order to provide a charge of the switched capacitor (C2, C2a, C2b) to the subsequent stage (104). The invention relates equally to a device (107) comprising such a sampling circuit and to a method of operating such a sampling circuit.

Abstract: The use of a dynamic current bias technique to dynamically bias a voltage switch of a sample-and-hold circuit is disclosed. Dynamically biasing the voltage switch mitigates nonlinear distortion caused by VBE (VGS) variation during charging and discharging the holding capacitor of the sample-and-hold circuit The bandwidth of the sample-and-hold circuit is enhanced.

Abstract: A track and hold (or sample and hold) offset compensated amplifier circuit that performs offset compensation in response to a comparison of sign (or sign and value) of the current forced to the output terminal of operational amplifier in order to keep it at the potential of holding capacitor during the holding phase. Based on this comparison, the comparison circuit increases or decreases the voltage differential applied between the positive and negative input terminals of the operational amplifier depending on whether the comparison circuit detects that the current forced to the output terminal of the operational amplifier is positive or negative. During the holding phase, negative feedback is disconnected, and the positive and negative input terminals of the operational amplifier are connected.

Abstract: In an analog buffer and a method for driving the same, by providing a pair of switches at a last comparing unit, a voltage level of an output signal is precharged as high as a source voltage level during a first offset period in an Nth initializing period, the voltage level of the output signal is discharged as high as a voltage level of a desired data signal during a discharging period in an Nth signal-applied period, then, the discharged voltage of the output signal, which overshoots a desired data voltage is compensated during a second offset period in the Nth signal-applied period to thereby output an accurate data voltage.

Abstract: An acquisition and averaging circuit is provided in which, during a sampling phase capacitors in sample blocks 4 and 6 are sequentially connected to the input signal to sample it and are then isolated so as to hold the sample. The capacitors are then connected to a combining/averaging arrangement such that an average of the sample values is formed.

Abstract: Circuitry is provided for controlling the slew rate of a negative output supply. The slew rate control circuitry includes an NMOS FET, a feedback resistor connected across the drain and the gate of the NMOS FET, an input resistor connected to the gate of the NMOS FET, level shifting circuitry connected between a positive output supply voltage and the input resistor, and a bias current source connected to the gate of the NMOS FET. A negative input supply voltage is connected to the source of the NMOS FET, and the negative output supply voltage is provided across a load connected to the drain of the NMOS FET. As the positive supply voltage ramps up from 0 to +VS, the level shifter provides a voltage to the input resistor that ramps up from ?VS to 0 volts. Further, the drain voltage of the NMOS FET ramps down from 0 to ?VS, thereby providing a negative output supply voltage ?VS with a slew rate that linearly tracks the slew rate of the master positive output supply.

Abstract: Disclosed is method of controlling an asymmetric waveform generator including the steps of providing a reference timer signal, and generating an asymmetric waveform as a combination of a first sinusoidal wave having a first frequency and a second sinusoidal wave having a second frequency approximately twice the first frequency. The generated asymmetric waveform is sampled to obtain a set of data points, which set of data points is indicative of the generated asymmetric waveform. The method includes analyzing the set of data points in terms of at least a first function relating to an ideal sinusoidal wave of the first frequency, to determine a first set of resultant values relating to the first sinusoidal wave, and analyzing the set of data points in terms of at least a second function relating to an ideal sinusoidal wave of the second frequency, to determine a second set of resultant values relating to the second sinusoidal wave.

Abstract: Frequency multiplying circuitry includes a couple of integrator circuits. The one integrator circuit charges a capacitor with a larger time constant via a resistor when an input clock signal is in its high level and then discharges it with a smaller time constant when the clock signal is in its low level. The other integrator circuit charges and discharges its capacitor in the opposite manner to the one integrator circuit as to the level of the clock signal. An output circuit compares the output voltages of both integrator circuits with a reference voltage and raises the level of its output signal when either one of the output voltages drops below the reference voltage. The duty ratio of the circuitry is therefore little susceptible to the frequency of the input signal and power supply voltage.

Abstract: A peak hold circuit which improves the precision of a hold voltage. The peak hold circuit includes a first input transistor which receives an input voltage and a second input transistor which receives the hold voltage. The peak hold circuit further includes a hold capacitor, a hold-voltage setting transistor and a bypass circuit. The hold capacitor supplies the hold voltage to the second input transistor. The hold-voltage setting transistor receives base current from the collector of the first input transistor and makes the hold voltage coincide with the input voltage in accordance with the base current. The bypass circuit bypasses bias current to be supplied to the second input transistor when the hold-voltage setting transistor is turned off.

Abstract: Analog circuits for providing one or more waveform parameters, e.g., the DC offset or average, of an analog input signal. Separate biasing is not necessarily required. Some embodiments comprise field-effect-transistors (FETs) configured in various diode-connected configurations that take advantage of leakage currents through the FETs so that long resistors or large capacitors are not necessarily required. One embodiment comprises two diode-connected FETs to provide an unbiased DC offset voltage of an analog input signal.

Abstract: A filtered reference voltage is provided with improved PSRR without the use of a large capacitor. First and second reference voltages are generated, where the reference voltages are centered about an input reference voltage. A first small valued capacitor circuit samples a selected one of the first and second reference voltages. The selected one is determined by the comparison between the filtered reference voltage and the input reference voltage. A second small valued capacitor circuit is periodically coupled to the first capacitor circuit such that charge redistribution occurs. The overall voltage on the second capacitor circuit is increased when the filtered reference voltage is less than the input reference voltage, or decreased when the filtered reference voltage is greater than the input reference voltage. The voltage from the second capacitor circuit is buffered to provide the filtered reference voltage. The overall system is suitable for an integrated circuit.

Abstract: A sample and hold device is provided in which sample switches are employed to switch between a sample phase and a hold phase. The sample and hold device provides alternate paths for the AC currents flowing to and from the sampling capacitor during the sample phase to mitigate the deleterious effects of the high AC currents through sample switches. The current drawn by the sampling capacitor from the input signal is replicated and directed to charge and discharge the sampling capacitor through alternate paths with respect to a path through the sample switches.

Abstract: A track-and-hold circuit including a pair of circuits each receiving input signals and providing half of a differential output signal. Each of the circuits of the pair includes an amplifier, and a configurable switch circuit coupled to a selectable reference voltages based on an expected input signal type. Each circuit includes a first switched capacitor circuit to sample its respective first input signal in response to a first clock phase, and to couple the sampled first input signal between the output and the negative input of the amplifier in response to a second clock phase. A second switched capacitor circuit samples its respective second input signal relative to an external common mode voltage in response to the first clock phase, and couples the sampled second input signal to a positive amplifier input relative to the selected reference voltage in response to the second clock phase.

Abstract: A sample and hold circuit includes an operational amplifier and a plurality of switched capacitors, the switched capacitors introducing a closed loop gain of one-half for the operational amplifier.

Abstract: An active feedback loop is provided in a switched-capacitor circuit to automatically cancel both junction and sub-Vth channel leakage. Low power consumption that is crucial for implantable medical devices is achieved. The circuit technique largely minimizes the effective leakage current when the switch is turned off. This circuit technique of the invention can be used in many different circuit applications.

Abstract: In order to reduce harmonic distortion, a track and hold circuit comprising a MOS transistor switch, a hold capacitor, and a voltage stabilizer for biasing bulk potential of the MOS transistor switch at a certain voltage is disclosed.

Abstract: When a switching signal SW is at “H”, TGs (3a and 5b) are turned on and an input voltage IN is supplied to a capacitor (4a) and a differential input unit (10a) through TG (3a). At this time, a differential input unit (10b) is connected to an output unit (20) through TG (5b) and a voltage follower circuit is constructed. A voltage held in a capacitor (4b) is outputted as an output voltage OUT from an output terminal (7). When the switching signal SW is set to “L”, TGs (3b and 5a) are turned on, and a voltage follower circuit is constructed by the differential input unit 10a and output unit (20). A voltage held on the input side of the capacitor (4a) and differential input unit (10a) is outputted as an output voltage OUT from the output terminal (7).

Abstract: A clock signal producing apparatus is composed of a detecting circuit and a clock signal outputting circuit. The detecting circuit detects edge timings of an input signal at which the input signal is inverted. The edge timings are quantized to a predetermined number of states. A clock signal outputting circuit outputs an outputted clock signal. A phase of the outputted clock signal is adjusted based on the edge timings.

Abstract: The present invention relates to a clock generator circuit which comprises a clock generator subcircuit which is operable to generate two clock signals having approximately the same frequency for use in sampling an analog signal in a generally alternating fashion. The clock generator circuit further comprises a pre-phase clock generator subcircuit associated with the clock generator subcircuit which is operable to generate two pre-phase clock signals, wherein each are associated with a respective one of the two clock signals generated by the clock generator subcircuit. In the pre-phase clock generator circuit, a signal transition of each of the pre-phase clock signals occurs before a signal transition of the respective clock signal generated by the clock generator subcircuit; in addition, a timing of a falling edge of the pre-phase clock signals is dictated by a global clock signal.

Abstract: A peak hold circuit that can operate to follow changes in peak value even if the changes are abrupt. The peak hold circuit (1) of the present invention has current control circuit (31), auxiliary switch element (25), and auxiliary constant current circuit (26). Current control circuit (31) counts the number of reference clock pulses RCK after output signal Vout becomes higher than analog voltage DI. When the number of clock pulses counted reaches a prescribed number or larger, auxiliary switch element (25) is turned on to operate auxiliary constant current circuit (26) to increase the amount of drop of output signal Vout per unit time. Consequently, even if output signal Vout becomes higher than the peak value of analog voltage DI, it is possible, by increasing the amount of drop of output signal Vout to make output signal Vout lower than analog voltage DI in a shorter amount of time than in the case in the conventional technology.

Abstract: A switched capacitor circuit includes an operational transconductance amplifier, a feedback stage having a first switched capacitor and a first time constant, and a load stage having a second switched capacitor and a second time constant. The first time constant and the second time constant are equal to each other to improve settling of the circuit. The first and second switched capacitors are coupled to an output of the operational transconductance amplifier via transistors. The transistors are sized so that the time constants of the feedback and load section are equal. In a further embodiment, the time constant of the feedback section is made greater than the load section, to further improve settling. On-state resistance of the transistors are controlled with respect to transconductance of the operational transconductance amplifier to maintain smaller error.

Abstract: A peak detector circuit providing a comparator that produces a low voltage output by pulling the output to common when an input signal exceeds a reference voltage and that produces a floating output by not conducting when the input signal does not exceed the reference voltage. A low output from the comparator generates a base current sufficient to drive a PNP transistor, which in turn drives current to a DC output capacitor. Until the input signal exceeds the reference voltage, neither the comparator nor the PNP transistor need to conduct and, consequently, the peak detector consumes relatively little power. The peak detector can be beneficially employed in a network interface unit or other transmission line unit.

Abstract: Disclosed is a peak hold circuit wherein output current corresponding to the peak value of input current is obtained for input currents with little change in magnitude, at essentially higher speeds. Detected drain current and input current of a P-MOS FET are compared, a first reference potential is applied to an NPN transistor, and a second reference potential lower than the first reference potential by a predetermined voltage such that the NPN transistor and a PNP transistor are not simultaneously turned on, is applied to the PNP transistor. In the event that the detected current is greater than the drain current, the NPN transistor is turned on and the PNP transistor is turned off, in the event that the detected current is smaller than the drain current, the NPN transistor is turned off and the PNP transistor is turned on, and in the event that the detected current and the drain current are equal, the NPN transistor and the PNP transistor are both turned off.

Abstract: A track and hold amplifier for use in analog/digital-converters comprises, in succession, an input buffer, a pn-junction switch and hold a capacitor. A feedback is provided between the hold capacitor and the input buffer and a second pn-junction switch is provided to disable the feedback during the hold mode.

Abstract: An improved sample and hold circuit for analog-to-digital conversion. The improvement incorporates an asymmetric drive high gain operational amplifier to rapidly slew the input voltage for maintaining a high sample rate. The asymmetric drive high gain operational amplifier allows increased current to be delivered in a uni-directional manner. The input nodes of the high gain operational amplifier are pre-charged to a predetermined reference voltage which further enhances the acquisition time. The asymmetric drive high gain amplifier may be switched off to conserve power consumption.

Abstract: A switched capacitor low-pass filter incorporates a plurality of integrator stages cascade connected together. The filter includes at least one stage that includes a circuit device for cancelling out glitch pulses. This device is a deglitching circuit provided within the filter. Preferably, each stage in the filter is formed of a deglitching device which acts as a smoothing integrator.

Abstract: The charge stored in a hold capacitor is prevented from leaking via the switches connected to the electrode of the capacitor, in a sample-and-hold circuit, and the reduction in the voltage held in the capacitor is suppressed, thereby improving the performance of the sample-and-hold circuit. The switches connected to the capacitor comprises two N-channel MOS transistors that are connected in series and are simultaneously turned on or off. During the period that the switches are in the OFF state, the potential at the interconnection node of the two transistors (one end of a first transistor) is set so as to be equal to that of the other end of the first transistor. Since the potential difference between both ends of the first transistor thereby becomes zero, leakage currents via the first transistor is reduced, and charge leakage in the capacitor can be prevented.

Abstract: The present invention relates to a high speed sample and hold circuit which comprises a plurality of sample and hold subcircuits coupled in parallel between an input and an output. The circuit also comprises a calibration circuit coupled to the plurality of sample and hold subcircuits. The calibration circuit is operable to modify a hold signal for one or more of the plurality of sample and hold subcircuits to thereby reduce timing mismatch between the plurality of sample and hold subcircuits and distortion associated therewith. The present invention also comprises a method of reducing timing mismatch in a high speed, parallel coupled sample and hold circuit. The method comprises detecting timing mismatch associated with a plurality of sample and hold subcircuits and modifying a hold signal for one or more of the subcircuits.

Abstract: An exemplary electronic circuit of the present include first and second buffers 34 and 38, which are preferably unity gain buffers. A first switch 36 (e.g., a NMOS transistor or a CMOS transmission gate) is coupled between the output of the first buffer 34 and the first terminal of a capacitor 40. The input of the second buffer 38 is also coupled to the first terminal of the capacitor 40. A second switch 42 is coupled between the second terminal of the capacitor 40 and a first voltage node Va and a third switch 44 is coupled between the second terminal of the capacitor 40 and a second voltage node Vb. This circuit can be used as an integrator in a number of applications.

Abstract: An improved sample and hold circuit for analog-to-digital conversion. The improvement incorporates an asymmetric drive high gain operational amplifier to rapidly slew the input voltage for maintaining a high sample rate. The asymmetric drive high gain operational amplifier allows increased current to be delivered in a uni-directional manner. The input nodes of the high gain operational amplifier are pre-charged to a predetermined reference voltage which further enhances the acquisition time. The asymmetric drive high gain amplifier may be switched off to conserve power consumption.

Abstract: A sample and hold circuit uses an auto-zero feedback technique to cancel the DC level of the input signal and reference this signal to a new baseline. The circuit is based on an op-amp with two separate feedback loops. The first feedback loop is connected to the same op-amp input as the incoming signal and contains a capacitor to store charge from this signal during sample mode and set the output voltage during hold mode. The second feedback loop uses an auto-zero feedback technique and contains an integrator having a predetermined reference voltage, thereby allowing the DC level of the input signal to removed without the need for capacitors in the gain path of the circuit. This allows the sample and hold circuit to extract an embedded time varying signal from the input voltage. It can be configured for a high gain, high pass function, without the need for large electrolytic capacitors in the gain path, removing the problems associated with such capacitors.

Abstract: A method and apparatus for performing voltage-mode sample and hold functions while avoiding nonlinear charge injection. The method comprises oversampling an input signal and sampling an error signal, not the input signal directly, and through signal processing causing the error signal to be reduced to low amplitude. First order and higher order voltage-mode sample and hold circuitry embodiments are provided.

Abstract: A switched Capacitor Track and Hold Amplifier having at least one signal input, at least one clock input and an output, comprising a sampling capacitor, a buffer amplifier connected between the input signal and the first plate of the sampling capacitor having high output impedance in the odd clock phase, a switch connected between the second plate of the sampling capacitor and a signal ground being closed in the even clock phase, means for copying the sampled input voltage to the output in the hold phase and means for controlling the output impedance of the input buffer amplifiers.

Abstract: A sample-and-hold device comprises a sampling transistor (Qech) and a sampling capacitor (Cech), the sampling transistor being off in hold mode in order to prevent the discharging of the sampling capacitor and conductive in sampling mode to apply a voltage to the capacitor that is substantially equal to the voltage (Vech) at its base.