Freescale Semiconductor,inc.

Fairchild Semiconductor Corporation

Integrated Device Technology, Inc.

Jack Cornish

Bin Zhao

Victor K Lee

Andrew Kameya

Brian Horng

Kenneth C Kwok

Jan Krellner

Weizhuang Wayne Xin

Stephen Ulbrich

Power control systems and power control devices may include a power control chip having a power control module configured to generate a power stage control signal, and at least one power stage having a timing control module that is physically separate from the power control module. The timing control module may be configured to receive the power stage control signal and generate a timing control signal controlling at least one switch to regulate an output voltage of the at least one power stage. A related method may include generating power stage control information indicating an offset between an output voltage and a desired regulated output voltage, transmitting the power stage control information between modules that are physically separate, and timing signals for controlling a switching converter to regulate the output voltage. A related method of auto-configuring a power control system is also disclosed.

Apparatuses and system having separate power control and timing control of a power control system and related method

In one general aspect, a power supply circuit can include a power stage configured to be coupled to a power source and configured to deliver an output voltage to a load circuit, and can include a comparator coupled to the power stage and configured to receive a reference voltage. The power supply circuit can also include a hysteresis control circuit configured to receive at least one of a feedback voltage or a reference voltage and configured to change a hysteresis of the comparator in response to the at least one of the feedback voltage or the reference voltage during a soft-start of the power supply circuit.

Apparatus and methods of soft-start in a hysteretic power converter

In one general aspect, an apparatus can include a controller, and a power stage coupled to the controller and configured to be coupled to a power source. The power stage is configured to deliver an output voltage to a load module in response to the controller. The apparatus also includes a reference voltage circuit coupled to the controller and configured to be grounded to a first ground voltage different from a second ground voltage associated with the load module.

Differential sensing for voltage control in a power supply circuit

First information is received at a first pulse width modulation (PWM) module responsive to a chip select signal being asserted at a chip select input of a communication bus of the first PWM module during a first time. The first information is latched at a control register of the first PWM module in response to a first logic transition of the chip select signal. A first PWM signal is provided at a first output of the first PWM module beginning a predetermined amount of time after the first logic transition of the chip select signal, the first PWM signal generated by the first PWM module based upon the first information.

Phase-shifted pulse width modulation signal generation device and method therefor

Disclosed are example techniques for frame-based power management in a light emitting diode (LED) system having a plurality of LED strings. A voltage source provides an output voltage to drive the LED strings. An LED driver generates a frame timing reference representative of the frame rate or display timing of a series of image frames to be displayed via the LED system. An update reference is generated from the frame timing reference. The LED driver monitors one or more operating parameters of the LED system. In response to update triggers marked by the update reference, the LED driver adjusts the output voltage of the voltage source based on the status of each of the one or more monitored operating parameters (either from the previous update period or determined in response to the update trigger), thereby synchronizing the updating of the output voltage to the frame rate (or a virtual approximation of the frame rate) of the video being displayed.

LED driver with frame-based dynamic power management

Techniques for dynamic headroom control in a light emitting diode (LED) system are disclosed. An output voltage is provided to drive a plurality of LED strings. A feedback controller monitors the tail voltages of the LED strings to identify the minimum tail voltage and adjusts the output voltage based on the lowest tail voltage. The LED strings grouped into subsets and the feedback controller is segmented such that, for a certain duration, a minimum tail voltage is determined for each subset. The minimum tail voltages of the subsets are used to determine the overall minimum tail voltage of the plurality of LED strings for the certain duration so as to control the output voltage in the following duration. The segments of the feedback controller can be implemented in separate integrated circuit (IC) packages, thereby facilitating adaptation to different numbers of LED strings by integrating the corresponding number of IC packages.

LED driver with segmented dynamic headroom control

A light emitting diode (LED) system implements a LED driver to drive a set of one or more LED strings. The LED driver includes a voltage source to provide an adjustable output voltage to a head end of each LED string of the set for a first duration and a second duration following the first duration. The LED driver further includes a feedback controller to control the voltage source to adjust the output voltage for the second duration based on a digital code value generated from a minimum tail voltage of one or more tail voltages of the set at a sample point of the first duration. The LED driver further includes a power controller to temporarily enable one or more components of the feedback controller for a sample period of the first duration, the sample period comprising the sample point.

LED driver with dynamic power management

A voltage source provides an output voltage to drive a plurality of light emitting diode (LED) strings. A LED driver adjusts the level of the output voltage so as to maintain the lowest tail voltage of the LED strings at or near a predetermined threshold voltage so as provide sufficient headroom voltages for current regulators for the LED strings. The LED driver operates in an operational mode and a calibration mode, which can be implemented in parallel with, or part of, the operational mode. During the calibration mode, the LED driver determines, for each LED string, a code value representative of the level of the output voltage necessary to maintain the tail voltage of the corresponding LED string at or near the predetermined threshold voltage. In the operational mode, the code values from the calibration mode are used to control the voltage source to provide an appropriate level for the output voltage.

LED driver with dynamic headroom control

Power management in a light emitting diode (LED) system having a plurality of LED strings is disclosed. A voltage source provides an output voltage to drive a plurality of LED strings. An LED driver implements a feedback mechanism to monitor the tail voltages of the active LED strings to identify the minimum tail voltage and adjust the output voltage of the voltage source based on the lowest tail voltage. A loop calibration module of the LED driver calibrates the feedback mechanism of the LED driver based on a relationship between a digital code value used to generate a particular output voltage and another digital code value generated based on the minimum tail voltage resulting from the particular output voltage.

LED driver with feedback calibration

Power management in a light emitting diode (LED) system having a plurality of LED strings is disclosed. A voltage source provides an output voltage to drive the LED strings. An LED driver monitors the tail voltages of the active LED strings to identify the minimum, or lowest, tail voltage and adjusts the output voltage of the voltage source based on the lowest tail voltage. The LED driver can adjust the output voltage so as to maintain the lowest tail voltage at or near a predetermined threshold voltage so as to ensure that the output voltage is sufficient to properly drive each active LED string with a regulated current in view of pulse width modulation (PWM) performance requirements without excessive power consumption.

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Foothill Ranch, CA, United States of America

Jack Cornish