Stmicroelectronics S.r.l.

Claudia Castelli

Alessandro Zafarana

Claudio Adragna

Adalberto Mariani

Francesco Villa

Alex Pojer

Fabrizio Fraternali

A control device for a switching regulator having two or more converter stages operating with interleaved operation, each converter stage including an inductive element and a switch element, generates command signals having a switching period for controlling switching of the switch elements, and determining alternation of a storage phase of energy in the respective inductive element and a transfer phase of the stored energy onto an output element. The control device generates the command signals phase-offset by an appropriate fraction of the switching period to obtain interleaved operation. In particular, a synchronism stage generates a synchronism signal and a control stage generates the command signals for the converter stages timed by the same synchronism signal.

Control device for a switching regulator with interleaved converter stages, switching regulator and corresponding control method

A control circuit controls a switching power factor corrector based on switch off-time modulation by controlling the input electric charge during on-time. The circuit includes a charge current generator that generates charge current as a replica of a current sense signal amplified with a gain corresponding to the square of peak value of a rectified input voltage, a loop capacitor charged with the charge current during on-time intervals and discharged with a discharge current during off-time intervals, a discharge current generator that generates the discharge current proportional to a product of a comparison voltage and a difference between a regulated output voltage and the rectified input voltage, and a PWM modulator that senses a charge voltage of the loop capacitor, turns on the switch for an on-time duration in response to detecting that the charge voltage nullifies, and turns off the switch when the on-time duration has elapsed.

Control circuit implementing a related method for controlling a switching power factor corrector, a PFC and an AC/DC converter

A method controls a power factor correction converter that includes a boost inductor and a switch. The method generates a sense signal representing a rectified AC input voltage or an inductor current through the boost inductor, turns on the switch in response to determining, based on the sense signal, a zero current condition through the boost inductor, turns off the switch after an on-time interval, generates a feedback signal based on an output voltage of the converter, and compares the feedback signal with a threshold. If the feedback signal is smaller than the threshold, the method generates a command signal, representing a phase domain including 0 and &#x3c0;, based on the feedback signal and the power threshold, and keeps the switch off when a phase of the input rectified AC voltage or of the inductor current is in the phase domain even if the zero current condition has been determined.

Method of controlling a power factor correction converter and related closed-loop control system

A managing system manages a plurality of VRMs associated with a plurality of microprocessors and connected in parallel together between first and second voltage references, the VRMs having output terminals connected together and arranged to communicate over a common bus. The managing system includes an error amplifier being input an output voltage signal from the VRM plurality, a reference voltage, and a droop voltage produced through an equivalent droop resistor receiving an output current signal from the VRM plurality and being connected to the common bus. The error amplifier effects a comparison of the input signals to generate a control voltage signal to the VRM plurality. Advantageously, the managing system comprises a controller connected to the equivalent droop resistor.

Managing system and synchronization method for a plurality of VRM-type modules

A voltage/current controller device, particularly for interleaving switching regulators, comprises: a DC/DC converter having a plurality of modules, with each module including a drive transistor pair connected in series between first and second supply voltage references, a current sensor connected to one transistor in the pair, and a current read circuit connected to the sensor. Advantageously, the read circuit comprises a transconductance amplifier connected across the current sensor to sense a voltage signal related to a load current being applied to each module, the transconductance amplifier reading the voltage signal with the transistor in the conducting state.

Voltage/current controller device, particularly for interleaving switching regulators

A charge counter for monitoring the charge of the battery state of an electronic device includes a sensing circuit of the charge and discharge current of the battery. The sensing circuit includes a differential amplifier having inputs coupled to the terminals of a sensing resistor of the battery current, a resettable integrator of the output signal of the amplifier, a first comparator and a second comparator of the output signal of the integrator generating a logic charge interrupt signal and a logic discharge interrupt signal, respectively. The sensing circuit also includes a switch for discharging the capacitance of the integrator momentarily closed by a logic circuit at every transition of the output signal of one or the other of the first and second comparators. Further, the sensing circuit includes a processor for the interrupts which monitors the state of charge of the battery, a timer for measuring the time elapsing from the start of a new integration ramp and the switching instant of either one of the first and second comparators, and a nonvolatile memory register containing the measure of the time interval of integration of the offset of the differential amplifier up to the switching of either of the first and second comparators.

Measuring counter of the state of charge of the powering battery of an electronic appliance

A method and apparatus to dynamically modify the internal compensation of a low drop out linear voltage regulator is presented. The process involves using zero mobile compensation; when the output pole of the voltage regulator moves, a compensating zero is moved toward higher frequencies. This compensation zero is used to compensate the effect of a second pole in the loop gain. The circuit includes an input stage having an error amplifier. The error amplifier includes a differential stage output coupled to an output terminal of the buffer stage. An output stage of the circuit includes an output transistor having a conduction terminal connected to an output terminal of the voltage regulator, and having a control terminal coupled to the output terminal of the buffer stage. Additionally, a variable compensation network is connected between the differential stage output and a voltage reference. This variable compensation network can include an RC circuit having a resistive transistor. The resistance value of the resistive transistor is modulated according to the output load current of the voltage regulator, thereby changing the location of the compensating zero.

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Brugherio, Italy

Claudia Castelli