Marvellworld Trade Ltd.

Marvell International Limited

Jiancheng Zhang

Sehat Sutardja

Runsheng He

Shaoan Dai

Sofjan Goenawan

Hong Zhang

A circuit including a first circuit, a second circuit, and a calibration circuit. The first circuit is configured to generate a first reference voltage potential. The second circuit is configured to generate a second reference voltage potential based on a calibration signal. The calibration circuit is configured to generate the calibration signal, to adjust the second reference voltage potential, based on the first reference voltage potential and the second reference voltage potential. The calibration circuit includes a comparing circuit configured to compare the first reference voltage potential and the second reference voltage potential, and a counter configured to increment a counter value based on the comparison of the first reference voltage potential and the second reference voltage potential and generate the calibration signal based on the counter value.

Low power and high accuracy band gap voltage circuit

A system includes a device configured to operate in a first mode and a second mode. The device includes a first circuit configured to receive a first band gap voltage potential from a first band gap circuit when the device is operating in the first mode, and a second circuit configured to receive a second band gap voltage potential from a second band gap circuit when the device is operating in the second mode. The device is configured to generate a mode select signal to selectively turn on and off the first band gap circuit and the second band gap circuit. A calibration circuit is configured to compare the second band gap voltage potential to the first band gap voltage potential, output a calibration signal to the second band gap circuit to adjust the second band gap voltage potential based on the comparison, and turn off the first band gap circuit in response to the second band gap voltage potential being within a predetermined range of the first band gap voltage potential.

Low power and high accuracy band gap voltage reference circuit

A voltage converter includes, among other things, an amplifier, a voltage combiner, and a hysteretic comparator. The amplifier has a first input terminal which receives a first voltage representative of an output voltage of the voltage converter, a second input terminal which receives a first reference voltage, and an output terminal which generates a second voltage proportional to a difference between the first voltage and the first reference voltage. The voltage combiner combines the second voltage with a second reference voltage to generate a combined voltage. The comparator causes a third voltage to decrease if a feedback voltage defined by the third voltage is detected by the comparator as being greater than a first threshold voltage defined by the combined voltage, and further to cause the third voltage to increase if the feedback voltage is detected by the comparator as being less than the first threshold. The third voltage is applied to a first terminal of a load external to the voltage converter.

Low power DC-DC converter with improved load regulation

A duty cycle estimator comprises an error generator that compares an output of a switching regulator to a reference to generate an output error, wherein the switching regulator operates in accordance with a switching period. An accumulator determines an accumulated error of the output error over a time period of at least N times the switching period of the switching regulator, where N is an integer. An adjustment determiner adjusts a duty cycle for the switching regulator based on the accumulated error of the output error over the time period.

Adaptive control loop

A controller comprises a duty cycle estimator to determine a nominal duty cycle. An adjustment determiner determines an adjustment value to combine with the nominal duty cycle to generate an adjusted duty cycle. A pulse width adjuster varies a pulse width signal based on the adjusted duty cycle. Transfer of energy between an input and a regulated output is based on the pulse width signal.

A band gap voltage reference circuit includes a first band gap circuit configured to generate a first band gap voltage potential. A second band gap circuit includes a variable resistance. The second band gap circuit is configured to output a second band gap voltage potential based on a value of the variable resistance. A calibration circuit is configured to adjust the variable resistance of the second band gap circuit based on the first band gap voltage potential and the second band gap voltage potential. The first band gap circuit is shut down in response to the second band gap voltage potential being within a predetermined range of the first band gap voltage potential.

A method of reducing switching losses in a switch array for an output regulator, the switch array to convert energy from an input source to a regulated output of the output regulator, the switch array including at least two power switches, includes determining an expected current flowing through the switch array during a next switching cycle, at a sampling rate, determining expected power losses of the switch array based on the expected current, determining a combination of the power switches to enable that minimizes the expected power losses, and enabling the combination of power switches.

Power array system and method

A method of sensing current comprises providing a current sensor having a gain resolution; setting the gain resolution of the current sensor to an initial resolution; sensing current flowing through the current sensor; evaluating an amplitude of the current; and changing the gain resolution of the current sensor based on the evaluating.

A band gap voltage reference circuit comprises a first band gap (BG) circuit that generates a first BG voltage potential. A second BG circuit includes a variable resistance and outputs a second BG voltage potential that is related to a value of said variable resistance. A calibration circuit communicates with said first and second BG circuits, adjusts said variable resistance based on said first BG voltage potential and said second BG voltage potential, and selectively shuts down said first BG circuit.

A digital controller that controls an output regulator includes controller sub-blocks that perform sub-functions of the digital controller, wherein at least one of the controller sub-blocks includes at least one of a delay line and a first comparator. A controller monitors output power states of the output regulator and controls flow of power to the at least one of the controller sub-blocks of the digital controller to reduce power consumption of the digital controller during selected ones of the output power states of the output regulator.

A duty cycle estimator determines a duty cycle for controlling a regulated output of an output regulator. The output regulator is responsive to the duty cycle for controlling a transfer of energy between an input source and the regulated output. An error generator compares the regulated output to an output reference to generate an output error. An accumulator determines an accumulated error of the output error over a time period of at least N times a switching period of the output regulator, where N is an integer. A reference generator generates reference levels. A comparator compares the accumulated error to the reference levels such that a single zero is generated, and generates the duty cycle based on the comparing.

A method of sensing current in an output regulator comprises providing a current sensor having a gain resolution, setting the current sensor gain resolution to an initial resolution, sensing a current flowing through the current sensor, evaluating an amplitude of the current, and at a sampling frequency, controlling the gain resolution of the current sensor based on the evaluating.

A digital controller for controlling a regulated output of an output regulator. The output regulator responsive to a pulse width signal for controlling the transfer of energy between an input source and the regulated output. The digital controller including a duty cycle estimator to determine a nominal duty cycle. An adjust determiner to determine an adjustment value to combine with the nominal duty cycle to generate an adjusted duty cycle. The pulse width signal being a function of the adjusted duty cycle.

A duty cycle limiter for limiting a transfer of energy between an input source and a regulated output of an output regulator. The output regulator having a regulator characteristic and a computed duty cycle for controlling the transfer of energy between the input source and the regulated output. The duty cycle limiter including a digital controller to generate a reference level and to compare the regulator characteristic of the output regulator to the reference level to determine a maximum duty cycle. The digital controller to control the reference level at a frequency at least equal to a switching frequency of the output regulator. The digital controller to limit the computed duty cycle to the maximum duty cycle.

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Los Altos Hills, CA, United States of America

Jiancheng Zhang