Abstract: An electrical switching system includes a constant-power controller and a switching device electrically coupled between a first node and a second node. The constant-power controller is configured to (a) generate a digital control signal to control the switching device, (b) control a duration of an active phase of the digital control signal at least partially based on a voltage across the switching device, and (c) control a peak value of the digital control signal to regulate a peak magnitude of current flowing through the switching device.

Abstract: An electrical switching system includes a constant-power controller and a switching device electrically coupled between a first node and a second node. The constant-power controller is configured to (a) generate a digital control signal to control the switching device, (b) control a duration of an active phase of the digital control signal at least partially based on a voltage across the switching device, and (c) control a peak value of the digital control signal to regulate a peak magnitude of current flowing through the switching device.

Abstract: An electrical switching system includes a constant-power controller and a switching device electrically coupled between a first node and a second node. The constant-power controller is configured to (a) generate a digital control signal to control the switching device, (b) control a duration of an active phase of the digital control signal at least partially based on a voltage across the switching device, and (c) control a peak value of the digital control signal to regulate a peak magnitude of current flowing through the switching device.

Abstract: An electrical switching system includes a constant-power controller and a switching device electrically coupled between a first node and a second node. The constant-power controller is configured to (a) generate a digital control signal to control the switching device, (b) control a duration of an active phase of the digital control signal at least partially based on a voltage across the switching device, and (c) control a peak value of the digital control signal to regulate a peak magnitude of current flowing through the switching device.

Abstract: A differential signal transfer system includes a dynamic level-shifter and a common-mode rejection device. The dynamic level-shifter is configured to (a) receive an input signal including a differential-mode component and a first common-mode component and (b) generate a level-shifted signal from the input signal, the level-shifted signal including the differential-mode component and a second common-mode component that is different from the first common-mode component. The common-mode rejection device is configured to receive the level-shifted signal and generate an output signal therefrom, where the output signal includes the differential-mode component.

Abstract: A differential signal transfer system includes a dynamic level-shifter and a common-mode rejection device. The dynamic level-shifter is configured to (a) receive an input signal including a differential-mode component and a first common-mode component and (b) generate a level-shifted signal from the input signal, the level-shifted signal including the differential-mode component and a second common-mode component that is different from the first common-mode component. The common-mode rejection device is configured to receive the level-shifted signal and generate an output signal therefrom, where the output signal includes the differential-mode component.

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

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

Abstract: A method and related circuit structure correlate the transconductance value of transistors of different type, for example MOS transistors and bipolar transistors. The structure comprises a first differential cell formed by transistors of the first type and a second differential cell formed by transistors of the second type connected to each other by means of a circuit portion responsible for calculating an error signal obtained as difference between the cell differential currents and applied to said first differential cell and to an output node of the same circuit structure obtaining a transconductance correlation independent from process tolerances and temperature.

Abstract: A bandgap voltage generator includes an output node for providing an output voltage, a current mirror coupled between the output node and a voltage reference, and a biasing transistor coupled to the output node. A feedback line includes a feedback transistor coupled to the output node. A current generator biases the feedback transistor by injecting a current into a bias node of the feedback line. A capacitor is coupled between the bias node and the voltage reference. The feedback line includes a circuit coupled between the bias node and the feedback transistor for causing a current to flow through the feedback transistor, and for increasing a resistance of a portion of the feedback line in parallel to the capacitor.

Abstract: An amplifying stage having a first circuit positioned between a first and a second reference voltage and having a first transistor with a first non-drivable terminal connected with a current supply and a second transistor having a first non-drivable terminal connected with a second non-drivable terminal of the first transistor, and the current supply connected to the first reference voltage, and a second circuit connected to the first circuit and fed by a current proportional to the current supplied by the current supply. The second circuit has at least one input terminal and is connected to a load. The first circuit has a connection between the first transistor and a drivable terminal of the second transistor for adapting current that passes through the second transistor to be the same as current from the current supply and the voltage between the first transistor and ground is greater than a saturation voltage between non-drivable terminals of the first transistor.

Abstract: A bandgap voltage generator includes an output node for providing an output voltage, a current mirror coupled between the output node and a voltage reference, and a biasing transistor coupled to the output node. A feedback line includes a feedback transistor coupled to the output node. A current generator biases the feedback transistor by injecting a current into a bias node of the feedback line. A capacitor is coupled between the bias node and the voltage reference. The feedback line includes a circuit coupled between the bias node and the feedback transistor for causing a current to flow through the feedback transistor, and for increasing a resistance of a portion of the feedback line in parallel to the capacitor.

Abstract: A method and related circuit structure correlate the transconductance value of transistors of different type, for example MOS transistors and bipolar transistors. The structure comprises a first differential cell formed by transistors of the first type and a second differential cell formed by transistors of the second type connected to each other by means of a circuit portion responsible for calculating an error signal obtained as difference between the cell differential currents and applied to said first differential cell and to an output node of the same circuit structure obtaining a transconductance correlation independent from process tolerances and temperature.

Abstract: An exponentially variable gain mixer circuit includes an oscillating circuit generating an alternating differential signal. A correction circuit is connected to the oscillating circuit and includes a first amplifier and a differential amplifier. The first amplifier receives an external gain variation command and generates a differential output signal that includes a control voltage and a bias voltage. The differential amplifier receives the alternating differential signal and generates a differential modulation signal. A variable gain mixer receives an input differential signal and generates an amplified differential signal as a function of the differential modulation signal and the control voltage.

Abstract: A variable gain amplifier is described which comprises a first device to which a first control signal (Vc, Vc1) is applied so that the gain (Ai1, Ai) of an output signal (iout, io) of the first device (11, 22, Q45-Q48) with respect to a first input signal (in, i1, ir) is a function of the exponential type of the first control signal (Vc, Vc1). The amplifier comprises a feedback network (25, Q51-Q58) connected between an output terminal and an input terminal of the first device (22, Q45-Q48) so as to assure that the gain (Ai) in decibel of the first device (22, Q45-Q48) is a linear function of the first control signal (Vc1).

Abstract: A method for reducing the settling time in PLL circuits, particularly for use in an RF transceiver, the PLL circuits including a phase comparator, a filter, a digital-analog converter and an adder that are suitable to produce in output a voltage (VC) for controlling a voltage-controlled oscillator provided by means of a varactor, the method including determining the dependency of the control voltage (VC) of the voltage-controlled oscillator on the frequency of a selected channel of a transmitter; and generating a law describing the variation of the output current (IDAC) of the digital-analog converter such that the voltage (VDAC) obtained from the output current of the digital-analog converter, added to an output voltage (Vf) of said filter keeps the filter voltage (Vf) constant in order to reduce the settling time of the PLL circuit as a selected channel varies.

Abstract: An exponentially variable gain mixer circuit includes an oscillating circuit generating an alternating differential signal. A correction circuit is connected to the oscillating circuit and includes a first amplifier and a differential amplifier. The first amplifier receives an external gain variation command and generates a differential output signal that includes a control voltage and a bias voltage. The differential amplifier receives the alternating differential signal and generates a differential modulation signal. A variable gain mixer receives an input differential signal and generates an amplified differential signal as a function of the differential modulation signal and the control voltage.

Abstract: A variable gain amplifier is described which comprises a first device to which a first control signal (Vc, Vc1) is applied so that the gain (Ai1, Ai) of an output signal (iout, io) of the first device (11, 22, Q45-Q48) with respect to a first input signal (in, i1, ir) is a function of the exponential type of the first control signal (Vc, Vc1). The amplifier comprises a feedback network (25, Q51-Q58) connected between an output terminal and an input terminal of the first device (22, Q45-Q48) so as to assure that the gain (Ai) in decibel of the first device (22, Q45-Q48) is a linear function of the first control signal (Vc1). (FIG.

Abstract: A low-noise quadrature phase I-Q modulator having a pair of Gilbert cell input stages driven by a feed voltage line and receiving in input respective square wave command signals coming from a local oscillator. The modulator comprises a transistor block with transistors connected to each cell and destined to carry out a voltage-current conversion of a signal in radio frequency received from the block itself; such block further including a single degeneration resistance.

Abstract: A current mirror circuit is provided with recovery having high output impedance. The current mirror includes a differential stage having a pair of transistors, and a voltage feedback loop which is stabilized and closed on a first one of the transistors of the differential stage. A second one of the transistors of the differential stage is connected, by its base terminal, to the collector terminal of an output transistor and, by its collector terminal, to the supply voltage. Moreover, the circuit includes a positive feedback loop which has the second transistor of the differential stage and the output transistor. A low-impedance circuit branch is connected to the base terminal of the second transistor of the differential stage and to the collector terminal of the output transistor.