| IWATT INC. Patent applications |
| Patent application number | Title | Published |
|---|
| 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 |
