721 results about "Switching power converter" patented technology

The present invention is a switching power converter that supports both a boost mode of operation and a buck mode of operation, uses one energy storage element, transitions smoothly between boosting and bucking, and avoids simultaneous boosting and bucking. The switching power converter uses a common duty-cycle timing signal and a common duty-cycle setpoint signal to provide a smooth transition between boosting and bucking, and to eliminate overlap between boosting and bucking. A voltage input error integrator is used to integrate out errors between an output voltage and a setpoint voltage to provide the common duty-cycle setpoint signal. Duty-cycle error integrators are used to integrate out errors between the common duty-cycle setpoint signal and the actual duty-cycle of either the buck converter or the boost converter. Non-overlapping boost operating and buck operating ranges are provided by the common duty-cycle setpoint signal.

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.

Disclosed is a multi-phase power regulator that accurately senses current at a load in a lossless manner and adjusts the power supplied to the load based on the sensed current. Also disclosed is a method of calibrating a multiphase voltage regulator by applying a known calibration current at the load and determining actual current values by the difference in measured values between when the known calibration current is applied and when it is not applied. The accurate current is determined at a known temperature and accurate temperature compensation is provided by a non-linear digital technique. Each phase of the multi-phase power regulator is individually calibrated so that balanced channels provide accurate power to the load. Also disclosed is a calibration method with minimal noise generation.

A switching power converter and method of controlling an output voltage thereof using predictive sensing of magnetic flux provides a low-cost switching power converter via primary-side control using a primary-side winding. The power converter has improved immunity to parasitic phenomena and other variations within the power converter components. An integrator is used to generate a voltage analog that represents magnetic flux within a power magnetic element via an integration of a voltage on a primary-side winding of the power magnetic element. A detection circuit detects the end of a half-cycle of post-conduction resonance that occurs in the power magnetic element subsequent to the energy level in the power magnetic element reaching zero. The voltage of the integrator is stored at the end of the post-conduction resonance half-cycle and is used to determine a sampling point prior to or equal to the start of post-conduction resonance in a subsequent switching cycle of the power converter (which is the predicted zero-energy storage point of the power magnetic element). The primary-side winding voltage is then sampled at the sampling point, providing an indication of the output voltage of the power converter. By predicting the zero-magnetic-energy storage point, the output voltage of a power converter operating in discontinuous or boundary conduction mode can be accurately controlled without being affected by parasitic phenomena or variations in circuit performance over time, input voltage and temperature.

A control system and method for simultaneously regulating the operation of a plurality of different types of switching power converters. The system utilizes in regulating the power converters sampled data and nonlinear feedback control loops.

A resonant switched power converter having switching frequency controlled in response to an output voltage thereof achieves over-current protection such as at start-up or under short circuit conditions using a resonant tank circuit which provides a notch filter in addition to a band pass filter. A additional band pass filter provided in the resonant tank circuit achieves increased power transfer to a load and reduced circulating resonant currents and conduction losses. The inductances of the preferred LCLCL tank circuit or other tank circuit with two pass band filters and a notch filter may be integrated into a single electrical component.

A switching power converter tracks a time-varying input voltage during each cycle of the input voltage to provide power factor correction. The switching power converter includes a switch with a frequency and duty cycle modulated control signal. The switch controls the transfer of energy between the input and output of the switching power converter. The frequency of the control signal is greater than a frequency of the input signal. The control signal frequency is modulated during each cycle of the input voltage so that energy transferred from the switching power tracks the energy supplied to the switching power converter.

A system for controlling a switching power converter and includes a digital controller that receives an analog signal representing the output DC voltage of the power converter for comparison to a desired output voltage level and generates switching control signals to control the operation of the power supply to regulate the output DC voltage to said desired output voltage level. At least two of the switching control signals having a dead time between a first edge of a first control signal and a second edge of a second control signal. The dead time is programmable such that the second edge of the second control signal may occur at a selected point in time either before or after the first edge of the first control signal.

A circuit and a method for controlling output current of cascaded switching power converters having a buck type output stage are disclosed. The circuit comprises two comparators for sensing input and output current, a logic gate for processing the output states of the comparators, and a pulse width modulator circuit for receiving the output of the logic gate and for controlling a switching power converter in accordance with this output. The method comprises simultaneous monitoring current in the stages of the converter, comparing the currents to the corresponding reference levels, generating the corresponding error signals, and controlling a pulse-width modulator circuit of a switching converter in accordance with these error signals.

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.

A resonant switching power converter having adaptive dead time control provides improved efficiency along with reduced EMI/audible noise and component stresses. A dead time between pulses generated by a switching circuit is adaptively set in conformity with a value of the input voltage to the resonant switching power converter and an indication of a magnitude of the current passing through inductive element of the resonant tank of the converter. The indication of the current magnitude may be the switching frequency of the converter, or a measure of line or load current levels. The dead time can be obtained from a look-up table or computed from the current magnitude and input voltage values.

A plurality of single-phase synchronizing converter automatically synchronize on a peer-to-peer basis. Each synchronizing converter is configured as a DC-to-DC converter. The synchronizing converters operate in parallel as a multi-phase converter. A common bus between the synchronizing converters includes a sync line and a common phase control line. Proper phasing automatically occurs when power is applied, and the phasing changes automatically as converters are added or removed. When the system powers up, the converters arbitrate for phase position. The phasing positions are random, but the phasing is relatively symmetrical regardless of the number of phases. In one embodiment, a hot-swappable converter module can be plugged into any location of a parallel multiphase bus to produce a common output voltage. When an additional module is plugged in, the converters readjust their phases to maintain phase symmetry. In one embodiment, each module shares a substantially equal portion of the output load.

A power control system includes a switching power converter and a programmable power factor correction (PFC) and output voltage controller. The programmable PFC and output voltage controller generates a control signal to control power factor correction and voltage regulation of the switching power converter. In at least one embodiment, the control signal is a pulse width modulated signal. The programmability of the PFC and output voltage controller provides the programmable PFC and output voltage controller flexibility to operate in accordance with programmable parameters, to adapt to various operating environments, and to respond to various operating exigencies. In at least one embodiment, the programmable PFC and output voltage controller includes a state machine to process one or more programmable, operational parameters to determine the period and pulse width states of the control signal.

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.

A control system and method for simultaneously regulating the operation of a plurality of different types of switching power converters. The system utilizes in regulating the power converters sampled data and nonlinear feedback control loops.

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.