Stmicroelectronics S.r.l.

Alessandro Bertolini

Alessandro Gasparini

Alberto Cattani

Stefano Ramorini

Salvatore Levantino

Massimo Antonio Ghioni

Mauro Leoncini

Paolo Melillo

Germano Nicollini

Tommaso Rosa

Massimo Ghioni

A boost DC-DC converter includes a switching network, coupled to an inductor, controlled by a PWM driving signal. A control loop receives a voltage output and provides the PWM driving signal. The control loop generates an error signal as a function of a difference between voltage output voltage and a reference, with the PWM driving signal generated based on the error signal. A low pass filter circuit within the control loop receives the PWM driving signal and provides at least one filtered signal. An adder node of the control loop receives the at least one filtered signal from the low pass filter circuit for addition to the at least one filtered signal. The PWM driving signal is generated as a function of a sum of the filtered signal and the error signal.

DC-DC converter apparatus and corresponding control method

A DC-DC boost converter includes an input receiving an input voltage and an output producing an output voltage. A switching stage is formed by a low-side transistor arranged between a switching node and a ground node, and a high-side transistor arranged between the switching node and the output. The high-side transistor includes a body diode having an anode coupled to the switching node and a cathode coupled to the output. The converter is controlled in an asynchronous operation mode where the low-side transistor is driven alternately to a conductive state and a non-conductive state, and the high-side transistor is driven steadily to a non-conductive state. A variable load circuit is selectively coupled between the two output terminals when the converter is in the asynchronous operation mode in order to sink a load current having a value that is a function of a value of the input voltage.

DC-DC converter circuit, corresponding method of operation and method of trimming a DC-DC converter circuit

In a multi-level hybrid DC-DC converter with a flying capacitor, a feedback circuit includes a first oscillator and produces a first clock signal with a frequency dependent on an output voltage. A second oscillator produces a second clock signal having a frequency dependent on a reference voltage. A logic circuit switches, as a function of the first and second clock signals, connection of the flying capacitor between one state where the flying capacitor is connected between an input node and a switching node, and another state where the capacitor is connected between the switching node and a ground node. The duty cycle of the first/second clock signal varies so that when the flying capacitor voltage is lower than a target voltage a duration of the one state is increased, and when the flying capacitor voltage is higher than the target voltage a duration of the another state is increased.

DC-DC converter circuit and corresponding method of operation

A time based boost DC-DC converter generates an output voltage using an inductor. A voltage error between the output voltage and a reference voltage is determined and processed in a) an integral control branch which converts the voltage error into an integral control current signal used to control a current controlled oscillator, and b) a proportional branch which converts the voltage error into a proportional control current signal used to control signal a delay line. Current flowing in the inductor is sensed, attenuated and used to apply adjustment to the integral and proportional control current signals. The output from the current controlled oscillator is passed through the delay line and phase detected in order to generate pulse width modulation (PWM) control signaling driving switch operation in the converter.

DC-DC converter apparatus with time-based control loop and corresponding control method, and computer program product

A supply node receives supply voltage and an output node provides a regulated output voltage to a load. A switching transistor is coupled between the supply and output nodes. The switching transistor is controlled by a drive signal generated by a control circuit to control switching activity. The control circuit includes circuitry to sense a feedback voltage indicative of the regulated output voltage and a comparator generating a comparison logic signal dependent on a comparison of the feedback voltage to a reference. A logic circuit generates a skip signal in response to the comparison logic signal. A counter generates a termination signal. Signal processing circuitry controls the switching activity by asserting the drive signal as a function of the skip signal and the termination signal.

Voltage regulator device

An amplifier circuit includes a first input stage with a differential input transistor pair and a second gain stage having an output node coupled to a load. A node in the first gain stage is coupled to the output node in the second gain stage. A feedback line couples the output node to the control node of a first transistor of the differential input transistor pair. Current mirror circuitry is coupled to a current flow path through a further transistor in the second gain stage and includes a sensing node configured to produce a sensing signal indicative of the current supplied to the load. The sensing signal at the sensing node is directly fed back to the control node of the first transistor of the differential input transistor pair to provide a zero in the loop transfer function that is matched to and tracks and cancels out a load-dependent pole.

Amplifier circuit, corresponding device and method

A control circuit operates to control a switching stage of an electronic converter. The control circuit includes: first terminals providing drive signals to electronic switches of the switching stage; a second terminal receiving from a feedback circuit a first feedback signal proportional to a converter output voltage; and a third terminal configured to receive from a current sensor a second feedback signal proportional to an inductor current. A driver circuit provides the drive signals as a function of a PWM signal generated by a generator circuit as a function of the first and second feedback signals, a reference voltage and a slope compensation signal. A mode selection signal is generated as a function of a comparison between the input voltage and the output voltage. A feed-forward compensation circuit is configured to source and/or sink a compensation current as a function of a variation in the mode selection signal.

Control circuit for controlling a switching stage of an electronic converter, corresponding electronic converter device and method

In a control circuit for a switching stage of an electronic converter, a phase detector generates a drive signal in response to a phase difference between first and second clock signals. The first and second clock signals are generated by first and second current-controlled oscillators, respectively. An operational transconductance amplifier generates first and second control currents in response to a difference between a reference and a feedback of the electronic converter, with the first and second currents applied to control the first and second current-controlled oscillators. In response to a switching clock having a first state, a switching circuit applies first and second bias currents to the control inputs of the first and second current-controlled oscillators, respectively. Conversely, in response to the switching clock having a second state, the switching circuit applies the second and first bias currents to the control inputs of the first and second current-controlled oscillators, respectively.

Control circuit for an electronic converter, related integrated circuit, electronic converter and method

A converter circuit includes first and second electronic switches coupled at an intermediate node, with an inductor coupled between the intermediate node and an output node. Switching drive control circuitry causes the first and the second electronic switch to switch between a conductive state and a non-conductive state. The drive control circuitry includes a first feedback signal path to control switching of the first and the second electronic switch as a function of the difference between a feedback signal indicative of the signal at the output node and a reference value. A second feedback signal path includes a low-pass filter coupled to the output node and configured to provide a low-pass filtered feedback signal resulting from low-pass filtering of the output signal. The second feedback signal path compensates the feedback signal as a function of the difference between the low-pass filtered feedback signal and a respective reference value.

Converter circuit, corresponding device and method

A control circuit for controlling switching operation of a switching stage of a converter includes a phase detector circuit that generates a pulse-width modulated (PWM) signal in response to a phase comparison of two clock signals. A first clock signal has a frequency determined as a function of a first feedback signal proportional to converter output voltage. A first transconductance amplifier generates a first current indicative of a difference between a reference voltage and the first feedback signal, and a second transconductance amplifier generates a second current indicative of a difference between the reference voltage and a second feedback signal proportional to a derivative of the converter output voltage. A delay line introduces a delay in the first clock signal that is dependent on the first and second currents as well as a compensation current dependent on a selected operational mode of the converter.

A switching converter includes a voltage conversion circuit providing an output voltage from an input voltage and a PWM voltage generated in response to first and second oscillating voltages. The input stage of a transconductor circuit provides an input reference current following a difference between a reference voltage and a voltage dependent on the output voltage and according to a transconductance, and an output stage for providing an output reference current from the input reference current. A phase shifter shifts an oscillating reference voltage according to the output reference current to obtain the first and second oscillating voltages. The transconductance is controlled in response to the input voltage resulting in a change of the input reference current. Compensation for that change is provided by subtracting a variable compensation current from the input reference current, where the variable compensation current is generated in response to the input voltage.

Switching converter with adaptive compensation

A DC-DC converter includes clock generation circuitry generating first and second clock signals that are out of phase, and a control signal generator generating a switching control signal at an edge of the second clock signal based upon a comparison of an error voltage to a summed voltage. Boost circuitry charges an energy storage component during an on-phase and discharges the energy storage component during an off-phase to thereby generate an output voltage. The on-phase and off-phase are set as a function of the switching control signal. Sum voltage generation circuitry generates a ramp voltage in response to an edge of the first clock signal and generates the summed voltage at an edge of the second clock signal. The sum voltage represents a sum of the ramp voltage and a voltage representative of the current flowing in the energy storage component during the on-phase.

Double clock architecture for small duty cycle DC-DC converter

An inductor and a shunt switch circuit are connected in parallel between an input node and an intermediate node. A first power transistor is connected between the intermediate node and a ground node. A second power transistor is connected between the intermediate node and an output node. The first and second power transistors are driven in response to a pulse width modulation (PWM) drive cycle having an on-time and an off-time. The input node receives a DC input voltage and a DC output voltage is generated at the output node. A control circuit senses the input and output nodes and determines whether the DC input voltage is within a threshold voltage of the DC output voltage. In response to that determination, the shunt switch circuit is turned on only during the off-time of the PWM drive cycle.

Boost DC-DC converter circuit with smart anti-ring circuit actuation

An auto-tuned ramp generator and a method for generating a sawtooth signal are provided. In the method and apparatus, a sawtooth signal is compared to a first reference voltage and a second reference voltage. In response to determining that the sawtooth signal does not exceed the first reference voltage, the voltage level of the sawtooth signal is increased. In response to determining that the sawtooth signal exceeds the second reference voltage, the voltage level of the sawtooth signal is decreased. The voltage level the sawtooth signal is retained if the sawtooth signal remains between the first and second reference voltages.

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Vermiglio, Italy

Alessandro Bertolini