Alpha and Omega Semiconductor (cayman) Ltd.

Intersil Americas Inc.

Alpha and Omega Semiconductor International LP

Nicholas Ian Archibald

Steven Patrick Laur

Rhys S A Philbrick

Rhys Philbrick

Allan Richard Warrington

A multi-phase current mode hysteretic modulator implements phase current balancing among the multiple power stages using slope-compensated emulated phase current signals and individual phase control signal for each phase. In some embodiments, the slope-compensated emulated phase current signals of all the phases are averaged and compared to the slope-compensated emulated phase current signal of each phase to generate a phase current balance control signal for each phase. The phase current balance control signal is combined with the voltage control loop error signal to generate a phase control signal for each phase where the phase control signals are generated for the multiple phases to control the phase current delivered by each power stage.

Multi-phase switching regulator incorporating phase current balance circuit

A controller for a switching regulator receiving an input voltage and generating a regulated output voltage includes a buck control circuit and a boost control circuit. The controller activates the buck control circuit to generate the regulated output voltage having a first voltage value less than the input voltage. The controller activates the boost control circuit to return charges stored on the output capacitor at the output node to the input node, thereby driving the regulated output voltage to a second voltage value lower than the first voltage value. In some embodiments, in response to a command instructing the controller to allow the output voltage to decay, the controller operates in the boost mode using the boost control circuit to recycle the stored charge at the output node while ramping down the output voltage.

Switching regulator implementing power recycling

A current mode control modulation includes a ramp signal generator generating a slope compensated ramp signal with slope compensation. In some embodiments, the ramp signal generator generates a ramp signal for the current control loop having a first ramp portion with slope compensation and a second ramp portion that matches the expected current mode signal. In some embodiments, the ramp signal generator includes a switched capacitor circuit supplied by a current circuit to charge or discharge nodes in the switched capacitor circuit to generate the ramp signal with slope compensation.

Current mode control modulator including ramp signal generator providing slope compensation

Multi-phase switching regulator with variable gain phase current balancing using slope-compensated emulated phase current signals

An apparatus, comprising, a MOSFET, a controller coupled to the MOSFET, an inductor conductively coupled to the MOSFET. A reported current output of the controller is adjusted based on a predetermined excursion of an attribute of the inductor from a fixed attribute value.

Inductor binning enhanced current sense

An error amplifier circuit receives first and second input signals and provides an error amplifier output signal indicative of the difference between the first and second input signals. The error amplifier circuit implements a proportional-integrator-differentiator (PID) circuit having a differential input signal path and including a proportional amplifier circuit, an integrator amplifier circuit, and a differentiator amplifier circuit. The differentiator amplifier circuit receives an AC coupled input signal. The error amplifier circuit sums the output from the proportional amplifier circuit, the integrator amplifier circuit and the differentiator amplifier circuit to provide the error amplifier output signal where the error amplifier output signal is referenced to a first bias voltage.

Digitally programmable, fully differential error amplifier

A ramp signal generator generates a slope compensated ramp signal with optimal slope compensation for a current mode control modulator. In some embodiments, the ramp signal generator generates a ramp signal for the current control loop having a first ramp portion with slope compensation and a second ramp portion that matches the expected current mode signal. In some embodiments, the ramp signal generator is implemented using a switched capacitor circuit with charge scaling to generate the ramp signal with optimal slope compensation built into the ramp signal.

Slope compensation for current mode control modulator

A voltage-controlled oscillator (VCO) generates a clock signal in response to an input feedback signal by applying tuning to a control loop error signal related to the input feedback signal and generating the clock signal using a voltage ramp signal that is ground referenced. The VCO includes an input tuning circuit applying tuning to a difference signal to generate a tuned voltage signal, a comparator to compare the tuned voltage signal to the ground-based ramp signal, an one-shot circuit to generate an one-shot signal pulse in response to the ramp signal increasing to the tuned voltage signal. The one-shot signal pulse is the clock signal and is also used to reset the ramp signal. In some embodiments, the voltage-controlled oscillator of the present disclosure is incorporated in a current mode hysteretic modulator.

Voltage-controlled oscillator for current mode hysteretic modulator

Slope compensation for peak current mode control modulator

A circuit for providing temperature compensation to a sense signal having a first temperature coefficient includes a temperature compensation circuit receiving a temperature sense signal indicative of a temperature associated with the sense signal where the temperature compensation circuit is digitally configurable by at least one digital signal to generate a compensating impedance signal having a second temperature coefficient. The compensating impedance signal provides an impedance value in response to the temperature sense signal. The compensating impedance signal is applied to modify the sense signal to provide a modified sense signal having substantially zero temperature coefficient over a first frequency range. The circuit further includes an amplifier circuit receiving the modified sense signal and generating an output signal indicative of the sense signal where the output signal has substantially zero temperature coefficient over the first frequency range.

DC resistance sense temperature compensation

A circuit for generating an output voltage to a top node of a plurality of LED strings. The circuit includes an inductor having a load current flowing therethrough and a switching transistor responsive to a switching control signal. An integrator generates a compensation voltage responsive to a voltage at a bottom node of the LED string and a reference voltage. Circuitry for combiningana correctionoffset with the compensation voltage is responsive to the compensation voltage and the load current through the inductor.The offset is generated only during a step load change of the load current and substantially reduces voltage transients from the compensation voltage and the output voltage.A summation circuit sums the compensation voltage including thecorrectionoffset with at least the voltage at the bottom node of the LED string to generate a first control signal. A latch generates the switching control signal responsive to the first control signal and a leading edge blanking signal.

Transient suppression for boost regulator

An embodiment of a power-supply controller includes a switching circuit and a transition circuit. The switching circuit is configured to generate a regulated output voltage by generating first current pulses at an approximately fixed frequency during a first mode, and generating second current pulses at a variable frequency during a second mode. And the transition circuit is configured to transition the switching circuitry from the first mode to the second mode in response to a length of one of the first current pulses. For example, a power supply may include such a power-supply controller to transition the supply from a PWM mode to a PFM mode under light-load conditions. To cause this transition at a predictable load point, the controller may monitor the lengths of the current pulses during the PWM mode, and may transition the supply to a PFM mode in response to the lengths being below a threshold.

Transitioning a power supply from a mode to another mode in response to a length of a portion of a current pulse

In an embodiment, an apparatus, such as a power-supply controller, includes a generator and an adjuster. The generator is configured to provide a switching signal that causes a power supply to generate a regulated output signal, and the adjuster is configured to impart a condition to the power supply while the power supply is operating in a first mode, the condition being approximately equal to a condition that the power supply would have if the power supply were operating in a second mode. For example, such an apparatus may be able to reduce or eliminate a transient on a regulated output signal (e.g., a regulated output voltage) when a power supply transitions from a first operating mode, such as a pulse-frequency-modulation (PFM) mode, to a second operating mode, such as a pulse-width-modulation (PWM) mode.

Smooth transition of a power supply from a first mode, such as a pulse-frequency-modulation (PFM) mode, to a second mode, such as a pulse-width-modulation (PWM) mode

An embodiment of a power-supply controller includes switching circuitry and an adjuster circuit. The switching circuitry is configured to cause a charging current to flow until the charging current has a predetermined relationship to a threshold, and to cause a discharging current to flow after the charging current. The adjuster circuit is configured to adjust the threshold in response to at least one of a charging period during which the charging current flows and a discharging period during which the discharging current flows. For example, a power supply may include such a power-supply controller to maintain a length of a current pulse, or of a portion thereof, within a particular range, such as approximately at a particular value, during a pulse-frequency-modulation (PFM) mode despite variations in one or more parameters such as input voltage, output voltage, filter capacitance, phase inductance, charging-current-sense impedance, and load, from their respective nominal values.

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San Francisco, CA, United States of America

Nicholas Ian Archibald