IWATT INC. Patent applications |
Patent application number | Title | Published |
20150222173 | POWER CONVERTER WITH FAST DISCHARGE CIRCUIT - A power converter with fast discharging to adapt to a load disconnect. The power converter comprises a magnetic component coupled between an input of the power converter and an output of the power converter. The magnetic component includes a primary winding and a secondary winding. A switch controls transfer of energy from the primary winding to the secondary winding according to on and off times of the switch. A discharge circuit is coupled to the output of the power converter. The discharge circuit is adapted to receive a signal indicative of whether the load is disconnected and to decrease an output voltage at the output of the power converter based on the signal indicative of whether the load is disconnected. | 08-06-2015 |
20150124494 | ADAPTIVE SYNCHRONOUS RECTIFIER CONTROL - The embodiments herein describe a switched mode power converter. In particular, the embodiments herein disclose techniques for adaptive synchronous rectification control. The switched mode power supply includes a synchronous rectifier controller that determines when to turn off the synchronous rectifier during each switching cycle based on a reference signal corresponding to when substantially all the power stored in a transformer of the power supply has been delivered to an electronic load. The synchronous rectifier controller may determine whether to adjust the reference signal used by the synchronous rectifier controller to turn off the synchronous rectifier during subsequent switching cycles. | 05-07-2015 |
20140268919 | SWITCHING POWER CONVERTER WITH SECONDARY TO PRIMARY MESSAGING - A primary-only power supply enables transmission of a signal or message from the secondary side of an isolated power supply to the primary side. To enable robust detection of the message without interfering with primary side sensing for output regulation, a configurable impedance current path is configured between the primary winding and ground. The primary side controller controls the configurable impedance current path to have a relatively low impedance during the normal mode and a relatively high impedance during the messaging mode. | 09-18-2014 |
20140268915 | POWERING A SYNCHRONOUS RECTIFIER CONTROLLER - The embodiments herein describe a switched mode power converter. In particular, the embodiments herein disclose a method for powering a synchronous rectifier controller that enables synchronous rectification in the switched mode power converter. The synchronous rectifier controller may be enabled by a regulator circuit or directly from the output voltage. | 09-18-2014 |
20140210357 | Adjusting Color Temperature in a Dimmable LED Lighting System - A LED lighting system, such as a dimmable LED lamp, that may simulate the performance of an incandescent bulb. LED strings of different colors may be connected to the output of a single LED driver that regulates an overall intensity of light produced by the LED lighting system. The color of the LED lighting system may be controlled by circuitry, such as one or more switches, that allocates current between the LED strings to change the color temperature of light emitted by the LED lighting system as the light intensity changes. | 07-31-2014 |
20140160810 | Digital Communication Link Between Secondary Side and Primary Side of Switching Power Converter - A switching power converter provides a communication link between a secondary side and a primary side of the switching power converter. During a messaging mode, the communication link enables information to be transmitted from an electronic device coupled to the secondary side to a controller on the primary side. The communication link may be used to transmit operating parameters related to powering the electronic device. The switching power converter may then adapt its switching operation to achieve different regulated output voltage and/or current to accommodate the detected electronic device. | 06-12-2014 |
20140159616 | ADAPTIVE HOLDING CURRENT CONTROL FOR LED DIMMER - A TRIAC dimmer controller for an LED lamp dynamically adjusts the amount of additional current supplied to the TRIAC dimmer based on the TRIAC dimmer operating mode. A TRIAC dimmer current controller continually senses the TRIAC dimmer current loading and determines a TRIAC dimmer operating mode based on the detected current. The TRIAC dimmer controller compares the detected current with a threshold current value called a TRIAC holding current, and adjusts the amount of bleeder current based on the difference between the detected current and the threshold current value. By continually sensing the TRIAC dimmer current loading, the LED controller regulates the amount of bleeder current supplied to the TRIAC dimmer using a single sink current path to satisfy the TRIAC dimmer current demands of multiple TRIAC dimmer operating modes. | 06-12-2014 |
20140159486 | TWO-INDUCTOR BASED AC-DC OFFLINE POWER CONVERTER WITH HIGH EFFICIENCY - Embodiments disclosed herein describe the use of two inductors in a non-isolated power converter. The power converter receives power from a non-regulated power source, and converts the received power to regulated output signals. Each inductor in the power converter receives power provided from the non-regulated power source via a switch controlled by a controller, and provides a regulated output to a power converter load. A first regulated output provided by a first inductor can be representative of a second regulated output provided by a second inductor. In addition, a voltage feedback signal can be provided for use by the controller based on the first regulated output and/or the second regulated output. | 06-12-2014 |
20140153292 | PRIMARY SIDE SENSE OUTPUT CURRENT REGULATION - The embodiments disclosed herein describe a method of a controller to maintain a substantially constant average output current at the output of a switching power converter. In one embodiment, the controller uses a regulation voltage that corresponds to the primary peak current regulation level to regulate the average output current. | 06-05-2014 |
20140103838 | ADAPTIVE DIMMER DETECTION AND CONTROL FOR LED LAMP - An LED lamp is provided in which the output light intensity of the LEDs in the LED lamp is adjusted based on the input voltage to the LED lamp. A dimmer control unit detects a type of dimmer switch during a configuration process. Using the detected dimmer type, the dimmer control unit generates control signals appropriate for the detected dimmer type to provide regulated current to the LEDs and to achieve the desired dimming effect. The LED lamp can be a direct replacement of conventional incandescent lamps in typical wiring configurations found in residential and commercial building lighting applications that use conventional dimmer switches. | 04-17-2014 |
20140085941 | AC-DC POWER SUPPLY INPUT VOLTAGE DETECTION AND MONITORING - A power converter includes a transformer with a primary and a secondary winding and a switch. A controller of the power converter at the primary winding side of the transformer generates a control signal to turn on or turn off the switch, the switch being turned on responsive to the control signal being in a first state and the switch being turned off responsive to the control signal being in a second state. The controller determines current through the primary winding generated while the switch is turned on and indirectly detects an input voltage to the power converter based on the current through the primary winding generated while the switch is turned on. The controller in turn may detect conditions such as a loss of power or brown out at the input of the power converter based on the indirectly detected input voltage. | 03-27-2014 |
20140085940 | Power System Switch Protection Using Output Driver Regulation - A controller of a switching power converter includes a voltage protection circuit that generates a modified supply voltage that does not exceed a predetermined threshold voltage to power one or more components of the controller. | 03-27-2014 |
20140085938 | PRIMARY FEEDBACK SWITCHING POWER CONVERTER CONTROLLER WITH INTELLIGENT DETERMINATION OF AND RESPONSE TO OUTPUT VOLTAGE DROPS DUE TO DYNAMIC LOAD CONDITIONS - The embodiments herein include a primary-side controller for a switching power converter that is capable of receiving a detection signal from a secondary-side detection circuit indicating that an output voltage has reached a condition. The controller determines the appropriate action once a detection signal has been received by distinguishing whether a dynamic load condition has been placed on the power supply versus other operating conditions. | 03-27-2014 |
20140078789 | SWITCHING POWER CONVERTER WITH SECONDARY-SIDE DYNAMIC LOAD DETECTION AND PRIMARY-SIDE FEEDBACK AND CONTROL - A power converter includes a transformer with a primary and a secondary winding. Feedback and control is maintained on the primary-side while a separate load detection circuit detects dynamic load conditions on the secondary-side. The load detection circuit detects dynamic load conditions at the time when a load is connected to the output of the switching power converter and, in turn, generates an alert signal. A coupling circuit coupled to the load detection circuit at the secondary winding side of the transformer and to the controller at the primary winding side of the transformer transmits the alert signal to the controller. The controller regulates the output voltage based on the feedback signal generated at the primary side of the transformer while detecting and responding to the dynamic load condition based on the alert signal generated at the secondary side of the transformer. | 03-20-2014 |
20140036549 | Switching Power Converter Dynamic Load Detection - A secondary-side dynamic load detection system and method rapidly identifies when a dynamic load has been placed on the output (e.g., when an electronic device is re-connected to the switching power converter). Once a dynamic load condition has been detected by the secondary side detector, a dynamic load detection signal is communicated from the secondary side of the switching power converter to a switch controller on the primary side. The switch controller can then quickly adapt switching in response to the dynamic load condition. | 02-06-2014 |
20140022829 | Hybrid Adaptive Power Factor Correction Schemes For Switching Power Converters - The embodiments disclosed herein describe a method of a controller of a switching power converter that provides a configurable power factor control method for the switching power converter. In one embodiment, the controller combines power regulation control methods of constant on-time control and constant power control to adjust the power factor of the switching power converter. | 01-23-2014 |
20140015447 | THERMAL DE-RATING POWER SUPPLY FOR LED LOADS - Embodiments disclosed herein describe the use of a power supply to provide power to an LED load. The power supply provides a present output current to the LED, and receives a temperature signal representing the operating temperature of the LED. A target output current is determined, for instance based on the temperature signal. An output current rate of change is determined, and the power supply adjusts the output current to the LED at the determined rate of change until the output current is substantially equal to the target current. | 01-16-2014 |
20130314454 | Selective Dimming to Reduce Power of a Light Emitting Display Device - Selective dimming in a light emitting display device to reduce power consumption. The display device includes a display panel that includes a plurality of light emitting pixels. An image processor is configured to divide an image frame into a plurality of regions and to reduce pixel intensity levels in at least one region of the plurality of regions to generate an adjusted image frame. The at least one region corresponds to a background of the image frame. A display driver converts data for the adjusted image frame into control signals for controlling brightness of the light emitting pixels. The display device may be, for example, an organic light emitting diode (OLED) display device or other type of display device that includes light emitting pixels. | 11-28-2013 |
20130314391 | PREDICTIVE POWER CONTROL IN A FLAT PANEL DISPLAY - A Predictive Power Control (PPC) device within a TCON Bias IC that addresses an overdesign inefficiency and enables a low cost solution. A PPC block utilizes the next frame image data and interacts with a pulse width modulation (PWM) control block of internal regulators to proactively prepare the output voltages of a power regulator for the power requirements in one or more future frames, for example. | 11-28-2013 |
20130307425 | CONSTANT CURRENT CONTROL BUCK CONVERTER WITHOUT CURRENT SENSE - A light emitting diode (LED) controller provides constant current regulation for a converter circuit providing current to an LED. The LED controller senses an inductor voltage and determines an inductor reset time from the sensed inductor voltage. Based on the determined inductor reset time, a switch on time and a switch period, the LED controller generates a control signal modifying the state of a switch coupling the converter circuit to an input voltage. | 11-21-2013 |
20130257280 | Delaying Startup Under Fault Conditions - A LED lamp that includes a LED lamp controller with delayed startup after a fault condition is detected. The type of the fault condition is used in determining a length of the startup delay, such as a number of power cycles during which the LED lamp controller is prevented from completing its configuration. Examples of different types of fault conditions include faults in a supply voltage or faults in a feedback voltage to the LED lamp controller. Fault type information can also be stored in circuitry that retains data and is not reset across the power cycles. | 10-03-2013 |
20130249437 | ADAPTIVE FILTER FOR LED DIMMER - A dimming controller for an LED lamp controls dimming using an adaptive filter to reduce or eliminate perceivable flickering and to provide smooth transitions during active dimming. During stable conditions, the adaptive filter operates with a relatively narrow bandwidth to filter noise that may lead to perceivable flickering. During active or startup conditions, the adaptive mapping filter operates with a high bandwidth to provide a quick response to the dimmer switch. | 09-26-2013 |
20130242629 | ON-TIME COMPENSATION FOR SWITCHING POWER CONVERTERS - An improved discontinuous current mode (DCM) switching power converter that compensates for the effect of dead time. The dead time of the switching power converter is measured during a switching cycle and a baseline on-time for a switch of the switching power converter is determined. The dead time and baseline on-time are used in calculating the desired on-time of the switch during a subsequent switching cycle of the power converter. The desired switch on-time regulates the output voltage to a desired voltage level. The desired switch on-time also maintains the average input current to the power converter in proportion to the input voltage, thereby improving the power factor of the switching power. | 09-19-2013 |
20130242625 | Adaptive Bipolar Junction Transistor Gain Detection - A power converter that controls a collector current of a bipolar junction transistor (BJT) by controlling the base current to the BJT after having determined the gain of the BJT. A gain detection block determines a gain of the BJT during a first mode. A current calculation block generates a current setting for the base current based on the gain of the BJT determined by the gain detection block during a second mode distinct from the first mode. In some embodiments, the power converter may be included in a LED lamp system. | 09-19-2013 |
20130241441 | Adaptive Compensation for Effects of Cat-Ear Dimmers on Conduction Angle Measurement - A dimmable light emitting lamp configured to interface with cat-ear dimmer switches. The lamp includes one or more light emitting devices. The lamp also includes circuitry configured to receive an input voltage and provide regulated current to the one or more light emitting devices. The input voltage has a first voltage pulse that does not represent a dimming level of a dimmer switch and a second voltage pulse that represents the dimming level of the dimmer switch. The circuitry determines a first duration corresponding to a length of the first voltage pulse and a second duration corresponding to a length of the second voltage pulse responsive to first duration. The circuitry adjusts the regulated current to the light emitting devices according to the second duration to adjust output light intensity of the light emitting devices. | 09-19-2013 |
20130241430 | Dynamic Control of Power Switching Bipolar Junction Transistor - The embodiments disclosed herein describe the dynamic control of a switching power converter between different operation modes of the switching power converter. In one embodiment, the operation modes of the switching power converter include a switching mode and a linear mode. The switching power converter may be included in a LED lamp system according to one embodiment. | 09-19-2013 |
20130241427 | POWER DISSIPATION MONITOR FOR CURRENT SINK FUNCTION OF POWER SWITCHING TRANSISTOR - The embodiments disclosed herein describe a method of a power controller for monitoring for unsafe operating conditions of a drive transistor in a switching power converter of a LED lamp system by predicting the power dissipation of the drive transistor based on knowledge of the current through the drive transistor and a continuous observation of the voltage across the drive transistor. When the drive transistor approaches unsafe operating conditions, the power controller turns off the drive transistor. | 09-19-2013 |
20130235621 | REGULATION FOR POWER SUPPLY MODE TRANSITION TO LOW-LOAD OPERATION - A switching power converter includes a controller configured to transition from a first operating mode to a second operating mode by determining the operating conditions at the transition point between the operation modes. The controller uses a point where a switch included in the power converter would have been turned on if operating under the first operating mode as a reference point to determine when to turn on the switch under the second operating mode. Using the reference point, the switching power converter determines a control period for regulating the switching period of the switch in a second operating mode. | 09-12-2013 |
20130169172 | Predictive Control of Power Converter for LED Driver - A system controls a switching power converter to power LED strings using a predictive feedforward control mechanism. An LED controller determines programmed current levels and duty cycles for driving LED strings. The LED controller determines a predicted load for a subsequent cycle of a switching power converter driving the LED strings based on the programmed current levels and duty cycles. A power conversion controller uses the predicted load information to control switching of the switching power converter. This improves the dynamic response of the switching converter to changing load conditions, thereby improving overall power efficiency and performance of the system. | 07-04-2013 |
20130147374 | HIGH PERFORMANCE ADAPTIVE SWITCHED LED DRIVER - An LED driver controls current through an LED string. The LED driver generates a boosted PWM signal to drive a PWM transistor in the LED current path such that the PWM transistor maintains a substantially constant V | 06-13-2013 |
20130121049 | EMI Frequency Spreading Method for Switching Power Converter - A controller of a switching power converter sets an actual turn-on time of a switch in the switching power converter in each switching cycle by selecting one of a plurality of valley points of the output voltage of the switching power converter occurring subsequent to the desired turn-on time of the switch. The desired turn-on time of the switch may be calculated according to the regulation scheme employed by the switching power converter. The controller selects one of the plurality of valley points randomly from switching cycle to switching cycle. The controller generates a control signal to turn on the switching power converter at the selected one of the plurality of valley points of the output voltage occurring subsequent to the desired turn-on time. | 05-16-2013 |
20130121044 | Power Converter Controller IC Having Pins with Multiple Functions - A controller integrated circuit (IC) for controlling a power converter uses one or more IC pins having plurality of functions such as configuration of a parameter supported by the controller IC and shutdown protection. Several different functions may be supported by a single IC pin, thereby reducing the number of pins required in the controller IC and also reducing the cost of manufacturing the controller IC. The controller IC may also share a comparison circuit among different pins and the different functions provided by those pins. Use of a shared comparison circuit further reduces the cost of manufacturing the controller IC without sacrificing the performance of the IC. | 05-16-2013 |
20130121032 | POWER SUPPLY REGULATION FOR ULTRA-LOW LOAD AND NO-LOAD OPERATION - A controller of a switching power converter employs a dynamically adaptive power supply regulation approach that improves low-load and no-load regulation to achieve ultra-low standby power in a switching power converter. Under ultra-low load conditions when a deep-deep pulse width modulation (DDPWM) is applied, the controller decreases the actual on-time of the power switch of the switching power converter by decreasing the “on” duration of the control signal used to turn on or off the power switch, until the “on” duration of the control signal reaches a minimum value. To further reduce the on-time of the power switch, the controller reduces the power applied to the power switch to turn on the switch more slowly, while maintaining the “on” duration of the control signal at a minimum value. The minimum value of the “on” duration of the control signal and the minimum power applied to the switch are dynamically controlled. | 05-16-2013 |
20130119954 | ADAPTIVE TRANSIENT LOAD SWITCHING FOR A LOW-DROPOUT REGULATOR - A low-dropout (LDO) voltage regulator includes a switch to generate an output current, and a first sensing module that increases the speed at which the switch is turned off and the output current is decreased in response to detecting a decreasing load current. The LDO regulator further includes a second sensing module that increases the speed at which the switch is turned on and the output current is increased in response to detecting an increasing load current. | 05-16-2013 |
20130107584 | Dynamic Mosfet Gate Drivers | 05-02-2013 |
20120274227 | ADAPTIVE DIMMER DETECTION AND CONTROL FOR LED LAMP - An LED lamp is provided in which the output light intensity of the LEDs in the LED lamp is adjusted based on the input voltage to the LED lamp. A dimmer control unit detects a type of dimmer switch during a configuration process. Using the detected dimmer type, the dimmer control unit generates control signals appropriate for the detected dimmer type to provide regulated current to the LEDs and to achieve the desired dimming effect. The LED lamp can be a direct replacement of conventional incandescent lamps in typical wiring configurations found in residential and commercial building lighting applications that use conventional dimmer switches. | 11-01-2012 |
20120223648 | Adaptive Switch Mode LED System - A system that provides an intelligent approach to driving multiple strings of LEDs. A processing device determines an optimal current level for each LED string from a limited set of allowed currents. The processing device also determines a PWM duty cycle for driving the LEDs in each LED string to provide precise brightness control over the LED string. The settings for the current level and duty cycle are transmitted to an LED driver for regulating the current and on-off times of the LED strings. Beneficially, the system reduces the size of the LED driver while leveraging existing resources available in the processing device to operate the LEDs in a power efficient manner. | 09-06-2012 |
20120176820 | Switching Power Converter Having Optimal Dynamic Load Response with Ultra-Low No Load Power Consumption - A switch controller is disclosed that adaptively controls the operating frequency of a switching power converter in order to improve one-time load response and repetitive dynamic load responses. During a transition from a high load to low load condition, the switch controller clamps the operating frequency of the switching power converter at an intermediate frequency for a period of time before allowing the operating frequency to return to a frequency associated with the low load condition. The clamped frequency is higher than the frequency associated with the low load condition thereby allowing improved response to a subsequent load change to a high load condition. Thus, the system improves dynamic load response without compromising no-load power consumption. | 07-12-2012 |
20120119720 | Load Transient Booster - A switching regulator comprises a PWM controller that controls switching of a power converter via a PWM control signal. The switching regulator detects load transients in the load driven by the power converter. Responsive to the detection of a load transient, the switching regulator resets a PWM clock synchronously with a fast clock operating at a higher frequency than the PWM clock. By doing so, the switching regulator beneficially responds more quickly to changes in the load than with conventional architectures that utilize only the slower PWM clock. This provides improved transient response without sacrificing power efficiency. | 05-17-2012 |
20110286248 | Adaptive Control for Transition Between Multiple Modulation Modes in a Switching Power Converter - In a switching power converter, PWM mode and PFM mode are separated into two independent control sections with the control voltage range in each control section determined independently. Each of the PWM and PFM modulation modes cannot operate continuously beyond its boundaries, thereby forming a control gap between the two control sections within which no continuous operation is allowed. In order to supply a load condition within the control gap, the power supply operates at the two boundaries of the control gap. Transition between PWM and PFM modes occurs fast, with low output voltage ripple. No limitation needs to be imposed on the control voltage range in each of the PWM and PFM control sections, because the control parameters in the PWM and PFM control sections need not be matched to one another, due to separation of the PWM and PFM modes by the control gap. | 11-24-2011 |
20110228569 | Switching Power Converter for Reducing EMI from Ring Oscillation and Its Control Method - A switching power converter ( | 09-22-2011 |
20110157945 | Synchronous Rectifier Circuit - A synchronous rectifier circuit rectifies an AC input voltage to produce a DC output voltage. The synchronous rectifier circuit comprises MOSFET switches coupled within the secondary transformer windings resulting in a shortened AC current path compared to conventional synchronous rectifier circuits. The shortened current path mitigates skin and proximity effects, substantially improving the power efficiency of the synchronous rectifier circuit. A rectifier assembly integrates one or more synchronous rectifier circuit within a magnetic core. | 06-30-2011 |
20110122658 | POWER CONVERTER USING ENERGY STORED IN LEAKAGE INDUCTANCE OF TRANSFORMER TO POWER SWITCH CONTROLLER - The power converter includes a transformer that is coupled or decoupled from a power source by a switch controlled by a switch controller. The transformer includes a first primary winding coupled to a secondary winding. The energy stored in the leakage inductance of the first primary winding is received by a second primary winding. The energy received by the second primary winding is provided to the switch controller to power the switch controller. The second primary winding is wound adjacent to the first primary winding to receive more energy from the first primary winding. | 05-26-2011 |
20110096572 | LOW POWER CONSUMPTION START-UP CIRCUIT WITH DYNAMIC SWITCHING - A start-up circuit in a switch-mode power converter that employs a Zener diode to provide a reference voltage to reduce the power consumption and the size of the start-up circuit. The start-up circuit also includes a coarse current source and a coarse reference voltage signal generator for producing current and reference voltage for initial startup operation of a bandgap circuit. The reference signal and current from coarse current source and the reference voltage signal generator are subject to large process, voltage and temperature (PVT) variations or susceptible to noise from the power supply, and hence, these signals are used temporarily during start-up and replaced with signals from higher performance components. After bandgap circuit becomes operational, the start-up receives voltage reference signal from the bandgap circuit to more accurately detect undervoltage lockout conditions. | 04-28-2011 |
20110012530 | ADAPTIVE DIMMER DETECTION AND CONTROL FOR LED LAMP - An LED lamp is provided in which the output light intensity of the LEDs in the LED lamp is adjusted based on the input voltage to the LED lamp. A dimmer control unit detects a type of dimmer switch during a configuration process. Using the detected dimmer type, the dimmer control unit generates control signals appropriate for the detected dimmer type to provide regulated current to the LEDs and to achieve the desired dimming effect. The LED lamp can be a direct replacement of conventional incandescent lamps in typical wiring configurations found in residential and commercial building lighting applications that use conventional dimmer switches. | 01-20-2011 |
20100225293 | ADAPTIVE CONTROL FOR TRANSITION BETWEEN MULTIPLE MODULATION MODES IN A SWITCHING POWER CONVERTER - In a switching power converter, PWM mode and PFM mode are separated into two independent control sections with the control voltage range in each control section determined independently. Each of the PWM and PFM modulation modes cannot operate continuously beyond its boundaries, thereby forming a control gap between the two control sections within which no continuous operation is allowed. In order to supply a load condition within the control gap, the power supply operates at the two boundaries of the control gap. Transition between PWM and PFM modes occurs fast, with low output voltage ripple. No limitation needs to be imposed on the control voltage range in each of the PWM and PFM control sections, because the control parameters in the PWM and PFM control sections need not be matched to one another, due to separation of the PWM and PFM modes by the control gap. | 09-09-2010 |
20100208500 | Detecting Light Load Conditions and Improving Light Load Efficiency in a Switching Power Converter - A switching power converter detects low load conditions based on the ratio of a first peak current value for peak current switching in constant voltage regulation mode to a second peak current value for peak current switching in constant current regulation mode. The power supply load is considered to have a low load if the ratio is lower than a predetermined threshold. Once a low load condition is detected, the switching frequency of the switching power converter is reduced to a level that minimizes switching loss in the power converter. In addition, the switching power converter also adjusts the switching frequency according to the sensed input line voltage. An offset is added to the switching period to reduce the switching frequency of the switching power converter, as the input line voltage is increased. | 08-19-2010 |
20100207655 | Method and Apparatus for Small Die Low Power System-on-chip Design with Intelligent Power Supply Chip - A method and system of system-on-chip design that provides the benefits of reduced design time, a smaller die size, lower power consumption, and reduced costs in chip design and production. The process seeks to remove the worst performance and worst power case scenarios from the design and application phases. This is accomplished by planning the power supply voltage in the design phase along with its tolerance with process corner and temperature combinations. The established plan is then applied with communications between power supply integrated circuits and load system-on-chip. | 08-19-2010 |
20100202165 | Dynamic Drive of Switching Transistor of Switching Power Converter - A switching power converter comprises a transformer ( | 08-12-2010 |
20100195355 | SWITCHING POWER CONVERTER WITH LOAD IMPEDANCE DETECTION - In a switching power converter, no-load condition is detected based on a variety of parameters including the output current, primary current, transformer reset time, and switching period. Once the no-load condition is detected, the switching power converter enters stand-by mode, in which the reference voltage corresponding to the target regulated output voltage of the switching power converter is lowered to a low stand-by value or the switching power converter is shut down for a predetermined duration. As a result, power loss during the stand-by mode of the switching power converter can be reduced significantly. | 08-05-2010 |
20100188873 | COMPENSATING ON-TIME DELAY OF SWITCHING TRANSISTOR IN SWITCHING POWER CONVERTERS - A switch controller compensates the total on-time delay of the switch in a switching power converter. The intended on-time of the switching transistor for the present switching cycle is reduced by the time difference between the actual on-time and the intended on-time of the switching transistor in the previous switching cycle in the switching power converter. The total delay of the switch in the switching power converter, including propagation delay, switch turn-on delay, and switch turn-off delay, can be compensated in real time, cycle by cycle. | 07-29-2010 |
20100165672 | VALLEY-MODE SWITCHING SCHEMES FOR SWITCHING POWER CONVERTERS - An improved valley-mode switching (VMS) scheme and circuitry for implementing the improved VMS switching scheme in a switch-mode power converter are disclosed. For a given switching cycle, a desired switch turn-on time is determined based on a pulse width modulation, pulse frequency modulation, or other suitable power converter control scheme. Also, one or more times corresponding to local minimums (valleys) are predicted for the voltage across a power switch of the switching power converter. The power switch is turned on at a valley immediately subsequent or otherwise subsequent to the desired switch time determined according to the power converter control scheme. Thus, the improved VMS scheme enables low-voltage switch operation to reduce switching loss and EMI noise without restricting the control scheme of the power converter. | 07-01-2010 |
20100164455 | ADAPTIVE MULTI-MODE DIGITAL CONTROL IMPROVING LIGHT-LOAD EFFICIENCY IN SWITCHING POWER CONVERTERS - Adaptive multi-mode digital control schemes that improve the light-load efficiency (and thus the overall average efficiency) in switch-mode power converters without causing performance issues such as audible noises or excessive voltage ripples. Embodiments include a switch-mode power converter that reduces current in the power converter using a second pulse-width-modulation (PWM) mode before reaching switching frequencies that generate audible noises. As the load across the output of the power converter is reduced, the power converter transitions from a first PWM mode in high load conditions to a first pulse-frequency-modulation (PFM) mode, then to a second PWM mode, and finally to a second PFM mode. During the second PFM mode, the switching frequency is dropped to audible frequency levels. Current in the power converter, however, is reduced in the second PWM mode before transitioning to the second PFM mode. Therefore, the power converter produces less or no audible noise in light load conditions where the switching frequency drops to audible frequency levels, while achieving high efficiency across varying load conditions. | 07-01-2010 |
20100157636 | CONTROLLER FOR SWITCHING POWER CONVERTER DRIVING BJT BASED ON PRIMARY SIDE ADAPTIVE DIGITAL CONTROL - A controller of an AC/DC flyback switching power supply uses adaptive digital control approaches to control the switching operation of a BJT power switch based on primary-side feedback to regulate the secondary-side constant output voltage and output current, without using the input line voltage. Switching-cycle by switching-cycle peak current control and limit are achieved based on the sensed primary-side current rather than the input line voltage in both constant-voltage and constant-current modes, operating in PWM, PFM and/or combinations of a plurality of PWM and PFM modes. The controller IC does not need a separate pin and ADC circuitry for sensing the input line voltage. The controller IC directly drives the BJT base, and dynamically adjusts the BJT base current amplitude cycle by cycle based on load change | 06-24-2010 |
20100111241 | Digital Phase Lock Loop with Multi-Phase Master Clock - A digital phase lock loop circuit with reduced jitter at the output is disclosed. The digital phase lock loop circuit includes a phase frequency detector that determines a phase difference between a feedback signal and a reference frequency signal to generate an error signal indicative of the phase difference. A numerically controlled oscillator generates a first oscillator output signal with a frequency proportional to the error signal and a second oscillator output signal indicative of jitter of the first oscillator output signal in reference to the reference frequency signal. A phase accuracy extender determines a delay amount from the second oscillator output signal and delays the first oscillator output signal by the delay amount to generate a phase-enhanced output signal with edges aligned with one of a plurality of reference clock signals. | 05-06-2010 |
20100013409 | LED Lamp - An LED lamp is provided in which the output light intensity of the LEDs in the LED lamp is adjusted based on the input voltage to the LED lamp. The LED lamp comprises one or more LEDs, and an LED driver configured to receive an input voltage and provide regulated current to said one or more LEDs, where the LED driver is configured to adjust the regulated current to said one or more LEDs according to the input voltage to adjust the output light intensity of said one or more LEDs. The LED lamp can be a direct replacement of conventional incandescent lamps in typical wiring configurations found in residential and commercial building lighting applications that use conventional dimmer switches that carry out dimming by changing the input voltage to the LED lamp. | 01-21-2010 |
20090322234 | LED DRIVER WITH MULTIPLE FEEDBACK LOOPS - An LED driver includes at least two interlocked closed feedback loops. One feedback loop controls the duty cycle of the on/off times of a switch connected in series to the LED string, and the other feedback loop controls the duty cycle of the on/off times of a power switch in the switching power converter that provides a DC voltage applied to the LED string. The LED driver of the present invention achieves fast control of the LED brightness and current sharing among multiple LED strings simultaneously in a power-efficient and cost-efficient manner. | 12-31-2009 |