Cirrus Logic Inc.

Other

Philips International, B.v.

Philips Lighting Holding B.v.

Mohit Sood

Rahul Singh

John L Melanson

Zhaohui He

Eric Jerome King

Siddharth Maru

Michael Allan Kost

Prashanth Drakshapalli

Firas Azrai

Robert Thomas Grisamore

Sunder S Kidambi

Jean-Charles Pina

John Christopher Tucker

Edwin De Angel

Daniel J Baker

Sahil Singh

Poornima Mazumdar

Roderick D Holley

Spencer Isaacson

Jie Fang

Vishwanathan Subramanian

An analog-to-digital conversion system may include an analog-to-digital converter configured to convert an analog input signal into an equivalent digital input signal, a first filtering path configured to filter the equivalent digital input signal to generate a first filtered digital signal, wherein the first filtering path comprises a zero-overshoot monotonic step response filter, a second filtering path configured to filter the equivalent digital input signal to generate a second filtered digital signal, wherein the second filtering path comprises a frequency-selective filter; and a mixer configured to either: (i) select between the first filtered digital signal and the second filtered digital signal in order to generate an output digital signal; or (ii) combine selected proportions of each of the first filtered digital signal and the second filtered digital signal in order to generate the output digital signal.

Dual-path digital filtering in an analog-to-digital conversion system

A data acquisition system may include an input for receiving an input signal for the data acquisition system, a plurality of data paths including a first data path and a second data path, and a signal estimator configured to determine a magnitude of the input signal using estimation of the input signal and dynamically deactivate one of the first and second data paths based on the magnitude of the input signal.

Minimizing power consumption in a data acquisition path

An electronic system and method include a controller to operate in a start-up mode to accelerate driving a load to an operating voltage and then operates in a post-start-up mode. A start-up condition occurs when the controller detects that a load voltage is below a predetermined voltage threshold level. The predetermined voltage threshold level is set so that the controller will boost the voltage to an operating value of a load voltage at a faster rate than during normal, steady-state operation. The controller causes a switching power converter to provide charge to the load at a rate in accordance with a start-up mode until reaching an energy-indicating threshold. When the energy-indicating threshold has been reached, the controller causes the switching power converter to (i) decrease the amount of charge provided to the load relative to the charge provided during the start-up mode and (ii) operate in a distinct post-start-up-mode.

Acceleration of output energy provision for a load during start-up of a switching power converter

A controller may predict an estimated occurrence of a high-resistance state of a dimmer, wherein the high-resistance state occurs when the dimmer begins phase-cutting an alternating current voltage signal. The controller may also be configured to operate in a trailing-edge exposure mode for a period of time wherein the period of time includes a time of the estimated occurrence of the high-resistance state in order to allow the controller to detect the occurrence of the high-resistance state, wherein energy is transferred from an input to a dissipative element during the trailing-edge exposure mode. The controller may further be configured to minimize a time between a beginning of the period of time and the estimated occurrence of the high-resistance state by modifying the period of time based on an estimated charging time of a capacitor of the dimmer.

Systems and methods for minimizing power dissipation in a low-power lamp coupled to a trailing-edge dimmer

A controller may be configured to generate a control signal to activate and deactivate a switch of a switching power converter in order to control a switching period and a peak current of the switching power converter to maintain a regulated current of the switching power converter at a desired current level such that: if the switching period decreases below a minimum switching period, the controller increases the switching period by a ringing period of a voltage of the switch and increases the peak current to compensate for the increase of the switching period in order to maintain the regulated current, and if the peak current increases above a maximum peak current, the controller decreases the switching period by a ringing period of the voltage of the switch and decreases the peak current to compensate for the decrease of the switching period in order to maintain the regulated current.

Systems and methods for valley switching in a switching power converter

In at least one embodiment, a lighting system receives an input signal, such as a supply voltage, that can be affected by a dimmer. The supply voltage can be affected by a dimmer when, for example, a dimmer phase cut (i.e. chopped) the supply voltage. A dimmer detection system of the lighting system determines if a dimmer is affecting the supply voltage. In at least one embodiment, the dimmer detection system also determines a type of the dimmer, such as detecting if the dimmer is a leading edge or trailing edge dimmer. In at least one embodiment, the dimmer detection system provides dimmer type data to one or more other circuits such as a switching power converter controller. The one or more other circuits utilize the dimmer type data to affect their operation.

Dimmer detection

A system and method include a controller that reduces power dissipated by a switch, such as a source-controlled field effect transistor, when an estimated amount of power dissipated by the switch exceeds a predetermined threshold. Reducing the power dissipated by the switch prevents damage to the switch due to overheating. The controller determines the estimated amount of power dissipated by the switch using actual drain-to-source current and drain voltage data. In at least one embodiment, the controller includes a fail-safe, estimated power dissipation determination path that activates when the drain voltage data fails a reliability test. Additionally, in at least one embodiment, the controller includes a model of thermal characteristics of the switch. In at least one embodiment, the controller utilizes real-time estimated power dissipation by the switch and the model to determine when the estimated power dissipated by the switch exceeds a power dissipation protection threshold.

Active thermal protection for switches

A power control system includes a switching power converter and a controller. The controller is configured to detect an over-current condition of an inductor current in the switching power converter using at least one non-inductor-current signal. In at least one embodiment, the switching power converter does not have a resistor or resistor network to sense the inductor current. In at least one embodiment, the controller indirectly determines a state of the inductor current using at least one non-inductor-current signal. Potentially damaging inductor current values that are, for example, greater than a normal maximum value or at a value that causes a discontinuous conduction mode system to operate in continuous conduction mode represent exemplary inductor over-current conditions addressed by one embodiment of the power control system.

Inductor over-current protection using a volt-second value representing an input voltage to a switching power converter

In at least one embodiment, an electronic system and method includes a controller to control a switching power converter in at least two different modes of operation depending on whether the controller detects a dimmer or not and/or whether a load requests more power than either of the two operational modes can provide. In at least one embodiment, the controller detects whether a dimmer is phase cutting an input voltage to a switching power converter. The controller operates the switching power converter in a first mode if the dimmer is detected, and the controller operates the switching power converter in a second mode if the dimmer is not detected. The controller also transitions between operating the switching power converter in the first mode and the second mode if a status of detection of the dimmer changes.

Multi-mode flyback control for a switching power converter

In at least one embodiment, a system and method provide current compensation in a lighting system by controlling a lamp current to prevent a current through a triac-based dimmer from undershooting a holding current value. In at least one embodiment, at least one of the lamps includes a controller that controls circuitry in the lamp to draw more lamp current for a period of time than needed to illuminate a brightness of the lamp at a level corresponding to particular phase-cut angle of the supply voltage. By drawing more current than needed, the controller increases the dimmer current during the period of time to prevent the dimmer current from falling below the holding current value. In at least one embodiment, the period of time corresponds to a compensating pulse of the lamp current at a time when the dimmer current would otherwise fall below the holding current value.

Mixed load current compensation for LED lighting

A control system provides a control signal to a nonlinear plant that generates a response signal responsive to the control signal. The control system includes a detector that detects a predetermined value of a plant quantity, valley switching logic, coupled to the detector, to change a state of a plant switch when the plant quantity is minimized, and a pulse-width modulator, coupled to the valley switching logic, to generate a control signal that controls the plant switch. The valley switching logic includes a nonlinear delta-sigma modulator that compensates for an error in a plant response signal by adjusting the duration of an on-time of a plant switch to cause an average value of the plant response signal to converge toward a target signal value.

Control system using nonlinear delta-sigma modulator with switching period error compensation

A method and apparatus for reducing switching noise in a system-on-chip (SoC) integrated circuit including an analog to digital converter (ADC) provides for reduced noise in the ADC conversions. Sampling circuits of the ADC are operated by sampling clock signals and digital circuits and other noise-generating circuits such as power converters, are operated by digital circuit clock signals. Both sets of clock signals are derived from the same master clock by a clock generator circuit, but an offset is applied in the clock generator circuit to move the edges of the digital circuit clock signals away from critical sampling intervals corresponding to edges of the sampling clocks. In one embodiment, the offset is applied by a processor core that forms part of the digital circuits by setting a value in the clock generator, which the clock generator then loads into the divider after halting the clock to the digital circuits.

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Austin, TX, United States of America

Mohit Sood