Abstract: A remotely controlled microphone amplifier has a first amplifier stage with a variable gain circuit operatively connected in the overall feedback loop of the first stage for controlling the gain in first increments. A unity gain second amplifier stage has variable attenuator operatively coupled between the output of the first amplifier stage and the input of the second amplifier stage. The variable attenuator controls the input to the second stage in second increments less than the first increments. The overall gain is linearly adjustable and varies in equal increments.

Abstract: A gain-controlled amplifier with a high dynamic range, useful in particular for frequencies in the GHz range, according to the invention comprises a bipolar or FET transistor (1) with an adaptive controlled feedback network (2) which may consist of one or a plurality of series connected diode(s) preferably PIN-diode(s). The transistor (1) and the controlling network (2, 3) can be operated at low voltages and current levels. Even for an operating frequency of 1 GHz and above, a gain control range of more than 20 dB can be obtained. Due to the feedback structure the linearity is enhanced especially for low gain values, and the controlled feedback does not degrade the noise figure. If used in an AGC loop circuit, the circuit current is increased for high input levels. Therefore the proposed circuit is suitable for battery powered receivers having input stages with automatic gain control.

Abstract: An oscillator includes an amplifier having an input and an output, and an impedance transformation network connected between the input of the amplifier and the output of the amplifier, wherein the impedance transformation network is configured to provide suitable positive feedback from the output of the amplifier to the input of the amplifier to initiate and sustain an oscillating condition, and wherein the impedance transformation network is configured to protect the input of the amplifier from a destructive feedback signal. One example of the oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to match the driving frequency of the oscillator to a plurality of tuning states of the lamp.

Abstract: A circuit includes a transconductance stage which converts an input signal power into a signal current and supplies it to an output of the circuit. A current diverting circuit branch is coupled to selectively divert the current from the transconductance stage away from the output. A feedback network feeds back a portion of the current diverted away from the output to the input of the transconductance stage. When implemented as a variable gain amplifier, the current diverting branch functions to change a gain of the circuit from a high level to one or more lower levels. The feeding back of a portion of the diverted current to the input improves the linearity of the circuit in the lower gain mode(s).

Abstract: A variable gain amplifier has a large variable range of a gain with respect to an analog signal having a level changing at a high-speed. The variable gain amplifier is provided with a digital-setting-type signal attenuator having a resistor string including a plurality of resistors connected in series. A maximum attenuation-factor limiting resistor is connected between the resistor string and a ground. Each of the analog switches is connected to respective points of the resistor string. A decoder generates a control signal for selecting at least one of the analog switches, the control signal being generated based on setting data provided from an external device. A voltage across the resistor string is divided by the resistors included in the resistor string, and the divided voltage is output to an amplifier from at least one of the analog switches selected by the control signal generated by the decoder.

Abstract: An amplification circuit includes an amplifying unit to which a signal supplied via an AC coupling capacitor is input, the amplifying unit starting an amplifying operation for the input signal when a potential level at an input portion of the amplifying unit reaches an operating threshold level from a predetermined low level, and a feedback resistor circuit, provided in a feedback line through which electric charge is fed back to the input portion of the amplifying unit, in which feedback resistor circuit a resistance value is controllable by a control signal supplied from an outside thereof.

Abstract: A control signal amplification circuit for amplifying a control signal reproduced by a control head. The control signal amplification circuit includes a level detection circuit for detecting an output level of an amplification circuit body having an amplification factor determined on the basis of the quantity of negative feedback to thereby send out a level control signal indicating a result of the detection, and a variable feedback resistance circuit which is connected between a minus-input terminal and an output terminal of the amplification circuit body so that the equivalent resistance value of the variable feedback resistance circuit decreases when the level control signal indicates the increase of the output level, and the equivalent resistance value of the variable feedback resistance circuit increases when the level control signal indicates the decrease of the output level, whereby the control signal is amplified without deformation of its waveform.

Abstract: A method and apparatus for adjusting the resistance across a slave transistor to follow a master resistor network are disclosed. A tuning circuit is disclosed which is used to control the effective resistance of a slave transistor for use in high speed integrated automatic gain control, equalizer, filter or equivalent types of circuits where low parasitic capacitance is desired. The invention provides a way to replace a resistor network and its associated high parasitic capacitance with an equivalent resistance having low parasitic capacitance. The invention replaces the resistor network, having large parasitic capacitance, with a slave transistor exhibiting an equivalent resistance, having low parasitic capacitance. An automatic tuning circuit containing a resistor network is located remotely to a circuit containing a slave transistor. The tuning circuit is then used to adjust the effective resistance of the slave transistor.

Abstract: There is disclosed a variable-gain circuit forming resistors on a semiconductor substrate. The ratio of the total resistance to the minimum resistance is made smaller than heretofore. The circuit is miniaturized. The variable-gain circuit comprises an operational amplifier, a first set of resistors R1-Rn+1, a second set of resistors Rx1-Rxm, switches SW1-SWn and a control circuit. This control circuit closes only one of the switches SW1-SWn at all times.

Abstract: A pre-amplifier circuit, which may be used in a variety of data recovery circuits to accurately recover data transmissions, includes an input regulatory circuit, a feedback circuit, and an amplifier. The input regulatory circuit regulates the magnitude of the data signal provided to the amplifier based on feedback signals from a feedback circuit. For low level data signals, the input regulatory circuit provides a fill, or almost full, representation of the data signal to the amplifier for amplification. But, when the data signal levels increase, the input regulatory circuit attenuates, based on the feedback signals, the data signals more and more before providing them to the amplifier, such that the output of the amplifier stays within a certain range.

Abstract: To realize a current-to-voltage conversion IC and a photoelectric conversion IC in which the available frequency range does not become narrower as the conversion gain is increased, in a current-to-voltage conversion IC that has a differential amplifier to which a negative feedback resistor of variable resistance is connected and a photodiode connected to the input terminal of the differential amplifier so that the output current of the photodiode is converted into a voltage by means of the negative feedback resistor, the differential amplifier is provided with a switch for varying the capacitance of a capacitor used as a phase compensating element so that the resistance of the negative feedback resistor and the capacitance of the differential amplifier are varied in an interlocked manner in accordance with a signal fed from outside.

Abstract: A RF integrated circuit including an amplifier having an input node and an output node; a switchable feedback path coupled between the output node and input node; and a switchable bias injector coupled to the input node. When the switchable feedback path is off and the switchable bias injector is on, the amplifier is in a high gain state. When the switchable feedback path is on and the switchable bias injector is off, the amplifier is in a low gain state. The circuit may be used in up converters and down converters for CDMA systems.

Abstract: An instrumentation amplifier for absolute voltage amplification having a balanced voltage inlet and a balanced voltage outlet. The voltage inlet is coupled to first amplification units having a very high open-loop gain, and which is further coupled with a feedback network provided between the outputs and second inputs of the amplification units.

Abstract: The present invention relates to a method and apparatus for adjusting the gain of an amplifier circuit. A gain control circuit compares the output of the amplifier with a reference voltage and adjusts a variable resistor, thereby altering the gain of the amplifier.

Abstract: The present invention relates to an internal voltage generating circuit. The internal voltage generating circuit comprises a reference voltage generating circuit for generating a reference voltage, which does not depend on an external power supply; and a comparator including a first input terminal, to which the reference voltage is supplied, a second input terminal, for comparing the voltages of the first and second input terminals and generating an output voltage according to the difference thereof at the output terminal; and an impedance element, which is selectively inserted between the output terminal and the second input terminal of the comparator according to an operation mode.

Abstract: An audio level compression circuit including a feedback differential amplifier to amplify an input signal and to feed back output signals through a feedback resistor, first and second comparators to compare the level of the upper and lower ends of the output signal from said feedback differential amplifier with first and second reference values respectively, and connected to provide the comparator outputs to the feedback resistor.

Abstract: An electronic balance adjusting circuit comprises a register for holding a balance data and capable of changing the balance data held in the register, a first ALU receiving the balance data held in the register for outputting a first digital value corresponding to a first ratio, and a second ALU receiving the balance data held in the register for outputting a second digital value corresponding to a second ratio having such an inverse increase/decrease relation to the first ratio that when the first ratio increases, the second ratio decreases and when the first ratio decreases, the second ratio increases. A first digital-to-analog converter receives the first digital value to output a first analog signal indicative of the first ratio, and a second digital-to-analog converter receives the second digital value to output a second analog signal indicative of the second ratio.

Abstract: The present invention relates to a gain control circuit for a low-noise amplifier. A gain control circuit of a 2-stage low-noise amplifier comprising an input stage noise matching circuit, an intermediate impedance matching circuit, a gain control circuit, and an output stage impedance matching circuit, said gain control circuit including: a feedback circuit connected to a transistor of second stage of the 2-stage low-noise amplifier, said feedback circuit detecting the amplified signal through the first stage and the second stage, and feeding the signal back through a switch circuit; and an attenuation circuit for compensating the harmonics of the input signal.

Abstract: The present invention relates to a gain controlled amplifier, and more particularly, to a gain controlled amplifier using active feedback and variable resistance. It is an object of the present invention to provide a gain controlled amplifier minimizing the gain and the degradation of power characteristics generated when adjusting gain in a variable gain amplifier which receives signals having different power levels, amplifies them in accordance with each power level and outputs output signals in a constant power level. In order to achieve the above object, a gain controlled amplifier in accordance with the present invention comprises an amplifier and an active feedback means for negative feedbacking the output of the amplifier to the input of the amplifier, and further has a feedback amount controller inputting the controlled feedback signal to the amplifier by controlling the feedback amount of said active feedback means.

Abstract: A pre-amplifier circuit, which may be used in a variety of data recovery circuits to accurately recover data transmissions, includes an input regulatory circuit, a feedback circuit, and an amplifier. The input regulatory circuit regulates the magnitude of the data signal provided to the amplifier based on feedback signals from a feedback circuit. For low level data signals, the input regulatory circuit provides a full, or almost full, representation of the data signal to the amplifier for amplification. But, when the data signal levels increase, the input regulatory circuit attenuates, based on the feedback signals, the data signals more and more before providing them to the amplifier, such that the output of the amplifier stays within a certain range.

Abstract: An amplifier with negative feedback, disposed in an integrated circuit arrangement, comprises an input amplification stage, configured to receive an input signal. A feedback stage configured to receive the output signal provided by the amplification stage, and provide a corresponding feedback signal to the amplification stage. A driver stage, coupled to the input stage, configured to receive the output signal provided by the amplification stage, and provide the output signal of the amplifier.

Abstract: A transimpedance amplifier circuit includes an inverting amplifier having an input being supplied with an input current, an output carrying an output voltage and a transconductance being adjusted as a function of the input current. A coupling member is connected between the input and the output of the inverting amplifier and has a controllable impedance. A differential amplifier has one input connected to the input and another input connected to the output of the inverting amplifier. A low-pass filter is connected downstream of the differential amplifier and has an output supplying a trigger signal for the coupling member.

Abstract: An inverting amplifier having variable gain in M discrete steps that are a fixed ratio F apart may be constructed by grounding the non-inverting input of a high gain differential gain element, and connecting the inverting input through a single-pole M-throw switch to the N.sup.th terminal in a ladder network of M cascaded elements. Each element is a series R and X, with X grounded, and their junction being where the next element of the ladder is connected. These junctions are also the aforementioned terminals of the ladder network, and are what are coupled to the M throws of the switch. At an input end of the ladder network is another impedance Z, to which the input V.sub.in is applied. At the other end of the ladder network is a final R in series with another Z that is driven by the V.sub.out obtained from the output of the gain element. Once Z and F are selected R and X may be found according to the relationships R=Z[.sqroot.(1/F)-1]and X=Z[.sqroot.(1/F)]/[.sqroot.(1/F)-1].

Abstract: An AGC circuit according to the present invention comprises: a gain controller, having a variable gain, for amplifying an input signal at a predetermined gain and generating an output signal, and for varying the gain; a comparison circuit for comparing an amplitude of the input signal or of the output signal with a predetermined reference level, and for generating a control signal that goes to a first level when the amplitude is smaller than the reference level, and that goes to a second level when the amplitude is greater than the reference level; and a duty ratio detector for supplying the control signal generated by the comparison circuit, and for generating control code in accordance with a duty ratio of the control signal, wherein the gain of the gain controller is varied by using the control code, and so adjusted that the duty ratio of the control signal is maintained to be a predetermined value.

Abstract: An electric signal processing circuit with an operational amplifier having a signal input, a feedback input and a signal output, and a nonlinear circuit device having a characteristic with a distortion-producing nonlinearity and located in the input signal circuit or in the feedback circuit of the operational amplifier, wherein a compensating circuit device having a characteristic with generally the same nonlinearity as the characteristic of the nonlinear circuit device is disposed in the feedback circuit or in the input signal circuit of the operational amplifier for compensating the distortion of the nonlinear circuit device.

Abstract: A mixing circuit that mixes a plurality of input signals are provided. A plurality of input terminals receive the input signals, respectively. A plurality of first resistors each providing input resistance each have one end thereof connected to a corresponding one of the input terminals, and another end thereof connected to corresponding ends of the other first resistors. A first amplifier has a positive input terminal to which the another end of each of the first resistors is commonly connected. A second resistor has one end connected to the output terminal of the first amplifier, and another end connected to the negative input terminal of the first amplifier. A second amplifier has a negative input terminal to which the another end of the second resistor is connected, with a positive input terminal thereof grounded. A plurality of third resistors are connected in series between the negative input terminal of the second amplifier and the positive input terminal of the first amplifier.

Abstract: An amplifier circuit with improved turn-on and turn-off transient operation includes a differential amplifier and a selectively variable reference generator for controlling the amplifier output during circuit turn-on. The amplifier has differential inputs which are driven by a reference voltage from the reference generator and a single-ended input signal. During circuit turn-on, the selectively variable reference voltage, generated by charging the bypass capacitor with a constant current source, charges in a linear manner from ground potential toward its final value of, typically, half of the power supply voltage. During circuit turn-off, the bypass capacitor is discharged with a constant current source in a linear manner toward ground potential. This allows improved turn-on and turn-off transient operation to be realized, e.g.

Abstract: An audio amplifier having an improved bi-polar transistor variable impedance circuit which is inexpensive to implement and which exhibits improved linearity. The resistance characteristic of the circuit is linearized with respect to the input signal strength through the addition of a diode between the control voltage and the base of the bi-polar transistor. This simple and inexpensive combination significantly improves the resistance linearity, allowing the transistor to handle significantly higher input signal voltages without increasing the output signal distortion. Additionally, the linearity of the control voltage response is improved through the addition of a second transistor-diode combination connected in current-mirroring relationship to the variable impedance transistor-diode combination. This circuit is particularly useful in applications requiring a wide-range open-loop control, such as a volume or tone control.

Abstract: An automatic gain control method and device capable of maintaining the gain within a predetermined proper range by first amplifying an input analog signal from a microphone or the like, then sampling the amplified analog signal while comparing the voltage thereof with a predetermined reference voltage, and when the number of times that the voltage of the amplified analog signal is higher than the reference voltage exceeds a predetermined number of times, varying the gain of the amplified analog signal stepwise in response to every excess beyond the predetermined number of times. Consequently it becomes possible to eliminate the necessity of an input amplifier of a sufficient bandwidth and an A-D converter, hence realizing manufacture of an improved device composed of a single-chip CMOS integrated circuit, with further advantages of minimizing the number of required component parts, reducing the production processes, achieving a higher integration density and lowering the power consumption.

Abstract: A transconductor is provided having a transconductance G.sub.m. This transconductance is then attenuated with a steering circuit (41) to attenuate the overall transconductance of the transconductor and vary the bandwidth. A fixed voltage is then input to the transconductor with the output thereof offset with a programmable current DAC (48). This output is then provided to an error amplifier (46) for developing an error voltage. This error voltage is then input back to the input of the transconductor to adjust the transconductance thereof to minimize this error. The steering circuit (41) is controlled by a voltage DAC (58) to program the attenuation provided thereby. Both the voltage DAC (58) and the current DAC (48) are controlled by a bandwidth control signal to program the bandwidth of the overall transconductor. This is facilitated while compensating for the process and temperature variations of the transconductance of the transconductor. This is also facilitated with a master/slave relationship.

Abstract: A pre-amplifier circuit, which may be used in a variety of data recovery circuits to accurately recover data transmissions, includes an input regulatory circuit, a feedback circuit, and an amplifier. The input regulatory circuit regulates the magnitude of the data signal provided to the amplifier based on feedback signals from a feedback circuit. For low level data signals, the input regulatory circuit provides a full, or almost full, representation of the data signal to the amplifier for amplification. But, when the data signal levels increase, the input regulatory circuit attenuates, based on the feedback signals, the data signals more and more before providing them to the amplifier, such that the output of the amplifier stays within a certain range.

Abstract: An analog signal conditioner for signals from high impedance sources adap for ready implementation as an integrated circuit. The signal conditioner includes a preamplifier, a step gain amplifier and a low-pass filter. A calibration generator can inject a calibration signal into the system. The step gain amplifier includes analog switches that control paths through a voltage divider network to provide negative feedback on both sides of a fully differential operational amplifier. The design of the feedback networks minimizes the total resistance on the integrated circuit.

Abstract: An automatic gain control circuit for controlling the gain of an amplifier amplifying an ac signal is provided which includes a resistance circuit, a comparing circuit, a gain control determining circuit, and a gain controlling circuit. The resistance circuit includes a plurality of resistors connected in series through taps. The comparing circuit compares an output signal of the amplifier with reference upper and lower limit values to determine whether the output signal of the amplifier is within a desired amplitude range of the reference upper limit value to the reference lower limit value or not. The gain control determining circuit determines whether the output signal of the amplifier has exceeded the upper and lower limit values sequentially during a complete cycle thereof for determining whether the gain of the amplifier should be changed or not.

Abstract: A negative feedback preamplifier having variable conversion gain control and variable open loop gain control capabilities which can work correctly regardless of semiconductor process variations. The negative feedback preamplifier used to convert an input signal current to a signal in the form of voltage includes: a resistor which determines the current-voltage conversion gain when a small signal current is input to the negative feedback preamplifier; a diode which switches the current-voltage conversion gain when a large signal current is input to the negative feedback preamplifier; a resistor which determines the current-voltage conversion gain when the large signal current is input; a grounded source amplifier including a main FET which is biased such that its transconductance decreases when the large signal current is input; and a bias setting portion (diode) which determines the bias condition associated with the main FET.

Abstract: An amplifier section is supplied with an electric signal outputted from a light-sensitive detector. The amplifier section comprises an amplifying circuit for amplifying the electric signal into an amplified signal having an amplified level. A producing section produces a control signal on the basis of the amplified signal and a reference voltage. A resistor section is connected to the amplifying circuit in parallel. The resistor section has a variable resistance which is varied in accordance with the control signal. A capacitor section has a capacitor and connects the input of the amplifying circuit and the output of the amplifying circuit through the capacitor in response to the control signal.

Abstract: A linearized voltage controlled amplifier (VCA) circuit uses the resistance of a gain control MOSFET to control amplifier gain in accordance with a DC gain control voltage. A gain control voltage is applied to the gain control MOSFET's gate through a gate input resistor that forms a voltage divider with a feedback resistor from the output of the amplifier. Since the VCA's output terminal is a low impedance node, the voltage divider network applies most of the gain control voltage to the gate of the gain control MOSFET. Conversely, a small fraction of the amplifier output signal is coupled to the gain control MOSFET's gate, to reduce distortion. The linearized VCA circuit is augmented by a gate drive correction circuit, through which the gain control voltage is coupled to the VCA's gain control MOSFET. The gate drive correction circuit is comprised of a difference amplifier and a compensating MOSFET that is matched with the gain control MOSFET of the VCA circuit for controlling its gate drive voltage.

Abstract: The present invention relates to a voltage gain amplifier for converting a single analog input to a differential output and controlling a voltage gain, comprising a single input charging/discharging part, a differential output operational amplifier, a first and second input voltage transferring part, a first and second voltage holding part and a frequency compensating part, and therefore, making it possible to generate a differential input signal, which is used as an input to an ADC(Analog-to-Digital Converter) of an audio CODEC(Coder/Decoder), by using a fully-differential output operational amplifier whose output is transmitted as a differential output. Also, the present invention gives an advantage of making the chip size smaller than the prior art does, resulting from the fact that resistors are replaced by capacitors and switches when integrated into a chip.

Abstract: An amplification circuit comprises an operational amplifier, an input resistance unit and a feedback resistance unit. The input resistance unit consists of a plurality of input resistances connected in series, and the feedback resistance unit consists of a plurality of feedback resistances connected in series. A plurality of adjusting pads are provided at respective connecting points of these input and feedback resistances. There is a common pad having an electrical potential fixed at a reference voltage. A first wire selectively bonds one of adjusting pads corresponding to the input resistances with the common pad to set a resistance value of the input resistance unit. And, a second wire selectively bonds one of adjusting pads corresponding to the feedback resistances with the common pad to set a resistance value of the feedback resistance unit.

Abstract: The system and method of enhancing the yield of flash memory circuit is disclosed. The method comprises performing a diagonal erase of a select group of memory cells on a wafer during sort. If the memory cells do not erase in a satisfactory manner, the control voltage applied to the memory cell is adjusted based on the memory cell's erase time. The circuitry for providing the adjustment voltage includes trimming circuitry for an incrementally increasing the applicable control of voltage.

Abstract: A monolithic amplifier includes a stable, high resistance feedback circuit and a dynamic bias circuit. The dynamic bias circuit is formed with active elements matched to those in the amplifier and feedback circuit to compensate for variations in the operating and threshold voltages thereby maintaining a stable resistance in the feedback circuit.

Abstract: An amplifier circuit (1) is arranged to amplify a signal of variable magnitude from a photodiode (3) having capacitive characteristics. The circuit (1) comprises a first feedback path containing a voltage controlled variable resistor (8) for varying the gain of the amplifier in relation to the magnitude of the signal so as to provide an output signal of substantially uniform magnitude. The first feedback path also contains a capacitor (7) which compensates for adverse effects of reactance in the circuit caused by the capacitance of the photodiode (3) and of the variable resistor (8) in order to optimize the frequency response characteristics of the amplifier. A second feedback path comprising a fixed value resistor (9) becomes operable when the resistance of the first feedback path is large to provide fixed gain amplification of signals received from the photodiode (3).

Abstract: A method for reducing the transient response time of a voltage regulator when the load attached to it is entering or exiting a lower power consumption level by changing the bandwidth of the voltage regulator without compromising its stability, and a bandwidth regulator for implementing such a method are disclosed, wherein the bandwidth of the voltage regulator is changed based on a signal sent by a control device when it senses that the component is about to change power consumption levels.

Abstract: A receiver (100) for receiving an input signal and generating an output signal therefrom has a switchable gain circuit (104) with a stepwise variable gain control (118), a local oscillator (106) and an automatic gain control (AGC) detector (114) with a response for detecting a level of the output signal and generating an AGC signal indicative of the level of the output signal and a state machine (116) being responsive to the AGC signal generating a control signal at the stepwise variable gain control to increase or decrease a gain of the switchable gain circuit in discrete stepwise steps.

Abstract: An input signal is applied to a first input terminal of a differential amplifier through an input resistance, and a feedback signal is applied to the first input terminal through a feedback resistance. A reference potential is applied to a second input terminal of the differential amplifier. A capacitance element is connected between the second input terminal and a high potential power supply, and a capacitance element is connected between the second input terminal and a low potential power supply. The amplification ratio of an amplification circuit can be switched over multiple stages by switching the resistance values of the input resistance and the feedback resistance by semiconductor analog switches. When any fluctuation exists in a power supply voltage, the fluctuation component is applied to the first input terminal of the differential amplifier through the semiconductor analog switches and causes a fluctuation of the amplification ratio.

Abstract: An amplifier circuit with improved turn-on transient operation includes a differential amplifier and a selectively variable reference generator for controlling the amplifier output during circuit turn-on. The amplifier is biased by a single power supply and its differential inputs are driven by a reference voltage from the reference generator and a single-ended input signal. Following circuit turn-on, the selectively variable reference voltage, generated by charging the bypass capacitor with a constant current source, charges in a linear manner from ground potential toward its final value of, typically, half of the power supply voltage. This allows improved turn-on transient operation to be realized, e.g. reduced "pops" and "clicks" upon circuit turn-on, while giving the user increased flexibility in selecting the sizes of the reference voltage bypass capacitor and the input signal coupling capacitor.

Abstract: An operational amplifier-based voltage multiplier circuit ("op amp circuit") implemented as an integrated circuit, and a memory chip including such an op amp circuit. The op amp circuit includes a variable operational feedback or input resistance (or a variable operational feedback resistance and a variable input resistance), and preferably also circuitry for controlling at least one variable resistance in response to control bits to cause the op amp circuit to assert a selected output voltage in response to a given input voltage. Preferably, each set of control bits determines a binary control word whose binary value has a simple functional relation to the value of the output voltage selected thereby. Preferably, the memory chip includes an array of memory cells (e.g, flash memory cells) and a control unit for controlling memory operations including programming, reading, and erasing the memory cells.

Abstract: A transconductance amplifier having a digitally variable transconductance includes a differential stage having a first differential output coupled to an output terminal via a first current mirror and a second differential output coupled to the output terminal via a second and third current mirror. The first and third current mirrors have multiple output branches for selectively supplying output currents to the output terminal in response to a binary transconductance control signal. In this way a digital control of the variable transconductance is realised, which can be used advantageously in a variable gain stage and in an automatic gain control circuit including such a variable gain stage.

Abstract: An integrated circuit has at least two components described in the form of two ideally matched transistors, each of which operate interdependently as a function of temperature and at least one physical parameter associated with each of said components when implemented in integrated form. The circuit further includes compensation means, disposed in the integrated circuit, for generating and applying a bipolar compensation signal to at least one of said components so that said two components interdependently operate predictably, consistently and independently of temperature variations and differences between the physical parameter of said two components. The bipolar current is necessary so that both the level and polarity of the compensation signal can be appropriately adjusted during the manufacture of the integrated circuit as a wafer so as to eliminate the need to compensate for any mismatches in the two components following such manufacture.

Abstract: A variable gain amplifier circuit in which a feedback circuit that feeds back the output signal of an amplifier from its output terminal to its input terminal is composed of an FET. The gate terminal of the feedback FET is connected to the output terminal of the amplifier through a capacitor, and the source terminal of the feedback FET is connected to the input terminal of the amplifier. The gain of the amplifying circuit is controlled by varying the transconductance of the feedback FET by controlling a bias voltage applied to the gate or drain terminal of the feedback FET. This makes it possible to control the gain independently of the physical dimension of the feedback FET, and at the same time, to prevent the input signal from being transmitted from the input side to the output side through the feedback circuit.

Abstract: An electronic circuit incorporating an operational amplifier and a feedback network consisting substantially of a plurality, N+M, of substantially identical non-linear elements connected in parallel in two groups of N and M elements each to provide a linear feedback stabilized gain or attenuation.