Abstract: The present invention is a double-layer multi-carrier ultra-wideband wireless communication method, wherein the frequency band for ultra-wideband communication is divided into a plurality of sub-bands, then one or more sub-bands are used for data transmission, and the Orthogonal Frequency Division Multiplex (OFDM) multi-carrier transmission technology is used in each sub-band. In the transmitting party, the data symbols to be transmitted are allocated on M branches corresponding to the M sub-bands, and the OFDM modulation is implemented on the data symbols on each branch to obtain M branches of parallel data, then digital baseband multi-carrier modulation is implemented on the M branches of parallel data. Thereby, the spectrum of data on each branch is moved onto the digital sub-band corresponding to the radio sub-band one to one, so the digital baseband signal of the radio signal to be transmitted is obtained.

Abstract: An LED controller reduces jitter of an LED lamp. In one embodiment, the LED controller includes a jitter detection circuit adapted to determine an amount of jitter in an input voltage signal. The input voltage signal includes a plurality of cycles and indicates an amount of dimming for the LED lamp. The LED controller further includes a jitter compensation circuit, which generates a control signal to control regulated in the LED lamp such that an output light intensity of the LED lamp substantially corresponds to the amount of dimming for the LED lamp. The control signal controls current delivery to the LED lamp to compensate for the determined amount of jitter in the input voltage signal.

Abstract: Back junction solar cells having improved emitter layer coverage and methods for their manufacture are disclosed. In one embodiment, a back junction solar cell includes an n-type base layer having an emitter layer formed from a first p-type doped region (e.g., formed by liquid phase epitaxial regrowth) and a second p-type doped region (e.g., formed by ion implantation) that extends beyond the first region. In various embodiments, this configuration permits the first p-type doped region to be formed with a border between it and the edges of the wafer (e.g., to prevent inadvertent shunting of the cell), while the second p-type doped region extends the emitter layer to improve emitter layer coverage. In certain embodiments, the second doped p-type region may extend to the edges of the wafer's n-type base layer.

Abstract: The embodiments herein describe a power converter including a controller that estimates input current of the power converter. The controller estimates the input current without explicitly sensing the input current. The estimated input current can be used in various applications such as regulating power factor and total harmonic distortion as well as estimating current required to maintain proper operation of a dimmer switch in light emitting diode lamp systems.

Abstract: A system for determining an initial position of a rotor (9) of a PMSM motor includes a motor controller (2) coupled to a plurality of phase windings of the motor by means of an actuation circuit (3). A processor (12) and an interface circuit (14) are coupled to the processor and the phase windings. The processor determines if the rotor speed is zero, and if so causes the actuation circuit to sequentially apply voltage signals (Vab, Vba, Vac, Vca, Vbc, and Vcb) to the phase windings to produce corresponding phase winding current signals (Iab, Icb, Ica, Iba, Ibc, Iac) in the various phase windings. The phase winding current signals are sensed and digitized. The processor then determines a position of a magnetic flux path associated with the rotor by computing the initial position of the rotor from one of the digitized phase winding current signals associated with the predetermined magnetic flux path.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The embodiments disclosed herein describe the adjusting of filter bandwidths in a multi-loop LED dimmer control circuit based on received dimmer input signals. The bandwidth of a filter in an active loop (a loop driving an LED power circuit) is decreased to prevent signal noise and associated LED flickering. Likewise, the bandwidth of a filter in an inactive loop (a loop not driving the LED power circuit) is increased to a pre-determined maximum in order to improve response time and decrease potential overshoot or undershoot during dimmer adjustment.

Abstract: 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.

Abstract: A system for determining an initial position of a rotor (9) of a PMSM motor includes a motor controller (2) coupled to a plurality of phase windings of the motor by means of an actuation circuit (3). A processor (12) and an interface circuit (14) are coupled to the processor and the phase windings. The processor determines if the rotor speed is zero, and if so causes the actuation circuit to sequentially apply voltage signals (Vab, Vba, Vac, Vca, Vbc, and Vcb) to the phase windings to produce corresponding phase winding current signals (Iab, Icb, Ica, Iba, Ibc, Iac) in the various phase windings. The phase winding current signals are sensed and digitized. The processor then determines a position of a magnetic flux path associated with the rotor by computing the initial position of the rotor from one of the digitized phase winding current signals associated with the predetermined magnetic flux path.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An adaptive switch mode LED driver provides an intelligent approach to driving multiple strings of LEDs. The LED driver determines an optimal current level for each LED channel from a limited set of allowed currents. The LDO driver then determines a PWM duty cycle for driving the LEDs in each LED channel to provide precise brightness control over the LED channels. Beneficially, the LED driver minimizes the power dissipation in the LDO circuits driving each LED string, while also ensuring that the currents in each LED string are maintained within a limited range. A sample and hold LDO allows PWM control over extreme duty cycles with very fast dynamic response. Furthermore, fault protection circuitry ensures fault-free startup and operation of the LED driver.

Abstract: A method for driving a brushless direct current (DC) motor is provided. The brushless DC motor has a first phase that is coupled between a first terminal and a common node, a second phase that is coupled between a second terminal and the common node, and a third phase that is coupled between a third terminal and the common node. The first and second phases are coupled to a first supply rail and a second supply rail, respectively, such that the brushless DC motor is in a first commutation state. The first phase is then decoupled from the first supply rail so as to allow first terminal to float during a window period. A first voltage difference between the first terminal and the second terminal is compared to a second voltage difference between the third terminal and the second terminal during the window period, and the brushless DC motor is commuted to a second commutation state if the first voltage difference is approximately equal to the second voltage difference.

Abstract: An adaptive switch mode LED driver provides an intelligent approach to driving multiple strings of LEDs. The LED driver determines an optimal current level for each LED channel from a limited set of allowed currents. The LDO driver then determines a PWM duty cycle for driving the LEDs in each LED channel to provide precise brightness control over the LED channels. Beneficially, the LED driver minimizes the power dissipation in the LDO circuits driving each LED string, while also ensuring that the currents in each LED string are maintained within a limited range. A sample and hold LDO allows PWM control over extreme duty cycles with very fast dynamic response. Furthermore, fault protection circuitry ensures fault-free startup and operation of the LED driver.

Abstract: The present invention is a double-layer multi-carrier ultra-wideband wireless communication method, wherein the frequency band for ultra-wideband communication is divided into a plurality of sub-bands, then one or more sub-bands are used for data transmission, and the Orthogonal Frequency Division Multiplex (OFDM) multi-carrier transmission technology is used in each sub-band. In the transmitting party, the data symbols to be transmitted are allocated on M branches corresponding to the M sub-bands, and the OFDM modulation is implemented on the data symbols on each branch to obtain M branches of parallel data, then digital baseband multi-carrier modulation is implemented on the M branches of parallel data. Thereby, the spectrum of data on each branch is moved onto the digital sub-band corresponding to the radio sub-band one to one, so the digital baseband signal of the radio signal to be transmitted is obtained.

Abstract: 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.

Abstract: Because there is a desire to migrate to sensorless, brushless direct current (DC) motors in large scale applications (i.e., vehicles), there is a need to provide a control system for such motors in large scale applications. Here, a motor controller is provided that uses small voltage pulses to generate currents (which are sufficiently small so as to not commute the motor) through pairs of phases. Based on the rise times of these currents, the motor controller can determine the initial position by using a lookup table (LUT) without commuting the motor.