Allegro Microsystems, LLC

Allergo Microsystems, LLC

Pranav Raval

Gregory Szczeszynski

Nai-Chi Lee

Bassem Alnahas

Vijay Mangtani

David Toebes

George P Humphrey

Methods and apparatus for a DC-DC converter having input voltage feedforward for reducing the effects of input voltage signal transients. In embodiments, a feedback circuit receives an output voltage and generates a feedback signal and a modulation circuit receives the feedback signal and generates a control signal for a switching element for generating the output voltage, which is boosted from an input voltage. A feedforward module combines a slope compensation signal, the input voltage, and current information for an inductive energy storage element, which forms a boost circuit for generating the output voltage and generates a ramp signal to the modulation circuit. A duty cycle of the control signal is proportional to an impedance compensation input, inversely proportional to the slope compensation and the input voltage, and inversely proportional to the inductor current.

DC-DC converter having feedforward for enhanced output voltage regulation

Methods and apparatus for a DC-DC converter having input voltage feedforward for reducing the effects of input voltage signal transients. In embodiments, a feedback circuit receives an output voltage and generates a feedback signal and a modulation circuit receives the feedback signal and generates a control signal for a switching element configured to generate the output voltage, which is boosted from an input voltage. A feedforward module combines the input voltage and current information for an inductive energy storage element, which forms a boost circuit for generating the output voltage, and provides a feedforward signal to the modulation circuit. The modulation circuit can generate the control signal from a ramp signal and the feedforward signal.

In one aspect, an integrated circuit (IC) is configured to receive an input signal and includes a boost duty cycle control circuit configured to provide duty cycle control to a power conversion stage configured to drive a load. The power conversion stage is configured to receive an input voltage. The IC also includes a current control circuit configured to control current of a first current source coupled to the first load and an inverter configured to provide an output signal comprising a negative of the input voltage, the output of the inverter configured to be coupled to the boost duty cycle control circuit.

Compensating for voltage changes in driver circuits

In one aspect, an integrated circuit (IC) is configured to receive an input signal. The IC includes a boost switch driver configured to provide a switching operation to a boost converter to drive a string of light emitting diodes (LEDs), a current sink driver connected to a current source and configured to provide a current signal to the string of LEDs, and a delay module configured to delay the current signal to the string of LEDs with respect to the input signal.

Controlling dimming ratio and output ripple voltage

An LED driver circuit selects a regulated voltage value for use in driving one or more LEDs based on dimming duty cycle. In some embodiments, the regulated voltage value may be selected in accordance with a function that decreases monotonically with increasing dimming duty cycle. In this manner, LED current accuracy can be achieved at lower dimming duty cycles, while still achieving enhanced operational efficiency at higher dimming duty cycles.

Driver circuit using dynamic regulation and related techniques

Methods and apparatus for a circuit including a DC-DC converter including: a boost converter to provide a DC voltage output from a DC input voltage, the DC output voltage configured to connect with a first load terminal, a feedback module configured to connect with a second load terminal, a switching module having a switching element coupled to the boost converter, and a control circuit coupled to the switching module to control operation of the switching element, the control circuit coupled to the feedback module, wherein the control circuit includes a slope generator to generate a ramp signal having a slope that can vary cycle to cycle.

Methods and apparatus for DC-DC converter having dithered slope compensation

An electronic circuit for driving a plurality of light emitting diode (LED) channels coupled to a common voltage node includes a priority queue for tracking a dominant LED channel. A queue manager may be provided to keep the priority queue updated during LED drive operations based on operating conditions associated with the LED channels.

LED driver having priority queue to track dominant LED channel

Control circuits and techniques are provided for use with DC-DC converters. The circuits and techniques may, in some implementations, be used with LED driver systems. In some embodiments control circuits are provided that rely on multiple different feedback paths to adjust a duty cycle of a DC-DC converter. In some embodiments, control circuits are provided that switch between multiple capacitors to provide as duty cycle control signal for use with a DC-DC converter.

Method and apparatus to control a DC-DC converter

A control circuit used to control a DC-DC converter includes a duty cycle control unit to control a duty cycle of the DC-DC converter and a hysteretic control unit to maintain a voltage at an output of the DC-DC converter within a narrow range during certain operational time periods. The hysteretic control unit may maintain the converter output voltage within the range by alternately enabling and disabling the duty cycle control unit based on feedback from the DC-DC converter output. In at least one embodiment, the control circuit is used within LED driver circuitry for driving a plurality of LED channels.

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Nashua, NH, United States of America

Pranav Raval