Abstract: A resonant power converter has a main switch, a resonant tank coupled across the main switch, and a signal processing circuit coupled to the main switch and the resonant tank. The signal processing circuit generates a driving signal for driving the main switch ON and OFF at a switching frequency. The resonant tank includes circuit components designed to have a resonant frequency that is tuned to a designed switching frequency of the main switch. The signal processing circuit includes a zero voltage switching (ZVS) circuit, a signal generator, a detection circuit, and a latch oscillator. The signal processing circuit is configured to adjust the switching frequency of the driving signal to be tuned to the actual resonant frequency of a resonant tank under very high switching frequency conditions, 1 MHz and greater, thereby accounting for the influence of parasitics at very high switching frequencies and achieving resonance of the circuit.

Abstract: A cascade power system includes a non-isolated buck converter in cascade with an isolated Class-E resonant circuit, where the Class-E resonant circuit operates at high frequency, for example 4 Mhz. Further, the non-isolated buck converter is configured as a current source coupled to the Class-E resonant circuit which provides a buck converter output voltage as input to the Class-E resonant circuit. The Class-E resonant circuit includes capacitive isolation for the cascade power system output.

Abstract: A cascade power system includes a non-isolated buck converter in cascade with an isolated Class-E resonant circuit, where the Class-E resonant circuit operates at high frequency, for example 4 Mhz. Further, the non-isolated buck converter is configured as a current source coupled to the Class-E resonant circuit which provides a buck converter output voltage as input to the Class-E resonant circuit. The Class-E resonant circuit includes capacitive isolation for the cascade power system output. The Class-E resonant circuit and the capacitive isolation are configured such that impedance matching for the resonant tank of the Class-E resonant circuit is independent of an output load condition.

Abstract: A power regulation control circuit is implemented as part of a power converter. The power regulation control circuit is implemented during two modes, a sleep mode and a wake-up mode. During the sleep mode, the power regulation control circuit detects a no-load presence and artificially increases the output voltage Vout to its maximum allowable value. This can be accomplished by pulling up an output of an error amplifier that feeds a PWM module. During the wake-up mode while the power converter wakes up from the sleep mode under maximum load, the output voltage Vout sinks from the artificially higher voltage, but still stays above a minimum operational voltage level. A slew rate compensation can be implemented to control a rate at which the output voltage drops when a load is applied. The artificially high output voltage during no-load condition and the slew rate compensation provide open loop voltage adjustment.

Abstract: A driver circuit is configured using a depletion-mode MOSFET to supply an output voltage across an output capacitor. The driver circuit includes a resistor positioned between two terminals of the MOSFET. In the case of an n-channel depletion-mode MOSFET, the resistor is coupled to the source and the gate. The circuit is a current controlled depletion driver that turns OFF the depletion-mode MOSFET by driving a reverse current through the resistor to establish a negative potential at the gate relative to the source. A Zener diode is coupled between the source of the depletion-mode MOSFET and the output capacitor to establish a voltage differential between the output and the MOSFET source.

Abstract: The power regulation control circuit is implemented during two modes. A first mode is a sleep mode and a second mode is a wake-up mode. During the sleep mode, the power supply detects a no-load presence and artificially increases the output voltage Vout to its maximum allowable value. In some embodiments, this is accomplished by pulling up an output of a error amplifier that feeds a PWM module. During the wake-up mode when the power supply wakes up from the sleep mode under maximum load, the output voltage Vout sinks from the artificially higher voltage, but still stays above a minimum operational voltage level. A slew rate compensation can be implemented to control a rate at which the output voltage drops when a load is applied. The artificially high output voltage during no-load condition and the slew rate compensation provide open loop voltage adjustment.

Abstract: A power converter includes a self-driven circuit for appropriately turning ON and OFF a synchronous rectifier during the operating cycle of the power converter. Without the use of a smart controller coupled to the synchronous rectifier, the self-driven circuit turns ON the synchronous rectifier during the positive cycle of the power converter when the main switch is turned OFF, and the self-driven circuit turns OFF the synchronous rectifier during the negative cycle of the power converter when the main switch is turned ON. Unlike conventional self-driven circuits that include an auxiliary secondary winding for driving a synchronous rectifier, the self-driving circuitry of the present application does not include an auxiliary secondary winding.

Abstract: A digital error feedback system, method and device adjusts the output voltage of a power converter. The digital error feedback system uses a digital comparator and one or more digital signal generators to generate and compare a digital signal corresponding to the output voltage to a reference digital signal in order to determine the current amount of error in the output voltage. The error is then able to be compensated for using a control signal generated based on the determined error.

Abstract: A power transmission pad is configured to provide wireless power transmission to multiple portable electronic devices where each device is orientation-free relative to the pad. The power transmission pad is also configured to be power adaptive by changing the power transmission level depending on the number of devices being concurrently charged. Each device, is placed within the magnetic field for the purpose of charging the device battery. The power transmission pad includes a sweep frequency generator for generating power transmissions across a frequency spectrum. The number of devices to be charged is determined as well as an optimal frequency for maximum energy transfer to each device. A single combined optimal frequency is determined using the optimal frequencies determined for each individual device. The sweep frequency generator is locked to the single combined optimal frequency and a power transmission level is set according to the number of devices.

Abstract: A power converter includes a primary side controller configured to operate the power converter in the discontinuous conduction mode during low to mid-power requirements and to operate the power converter in the continuous conduction mode during high or peak power requirements. The power converter includes a primary side auxiliary winding that provides a feedback signal to the primary side controller, and an adjusted resistor and diode circuit which is coupled to a multi-function feedback (FB) pin of the primary side controller. The primary side controller monitors for a peak power demand, upon detection of which a negative supply rail is enabled, which is used to compensate for voltage losses due to non-zero current while operating in the CCM, thereby enabling output voltage regulation while operating in the CCM during peak power demand.

Abstract: A cascade power system includes a non-isolated buck converter in cascade with an isolated Class-E resonant circuit, where the Class-E resonant circuit operates at high frequency, for example 4 Mhz. Further, the non-isolated buck converter is configured as a current source coupled to the Class-E resonant circuit which provides a buck converter output voltage as input to the Class-E resonant circuit. The Class-E resonant circuit includes capacitive isolation for the cascade power system output. The cascade power system further includes a feedback control circuit for regulating a system output voltage. A feedback signal is used to adjust a duty cycle of the buck converter, thereby adjusting a buck converter output voltage. The buck converter output voltage is provided as input to the Class-E resonant circuit.

Abstract: A power transmission pad is configured to provide wireless power transmission to a receiving device where the receiving device is orientation-free relative to the pad. The pad functions as a transmitter and is magnetically “hot”, meaning the pad generates a magnetic field when powered on. The receiving device, such as a cell phone, tablet, or other portable electronic device, is placed within the magnetic field for the purpose of charging the device battery. In contrast to conventional wireless battery charging systems, there are no restrictions on the orientation of the receiving device relative to the pad. The power transmission pad includes a sweep frequency generator for generating power transmissions across a frequency spectrum. An optimal frequency is determined for maximum energy transfer to the receiving device, and the sweep frequency generator is locked to the determined optimal frequency.

Abstract: A power transmission pad is configured to provide wireless power transmission to multiple portable electronic devices where each device is orientation-free relative to the pad. The power transmission pad is also configured to be power adaptive by changing the power transmission level depending on the number of devices being concurrently charged. Each device, is placed within the magnetic field for the purpose of charging the device battery. The power transmission pad includes a sweep frequency generator for generating power transmissions across a frequency spectrum. The number of devices to be charged is determined as well as an optimal frequency for maximum energy transfer to each device. The sweep frequency generator is set to cycle through the optimal frequencies determined for each device.

Abstract: A switched mode power converter includes a closed loop feedback control mechanism for regulating an output characteristic and a resonant type circuit for inclusion of resonant energy delivery. The characteristic impedance of the resonant type circuit is modified from an optimal energy transfer configuration to one that dampens fluctuations in a feedback signal used by the closed loop feedback mechanism. The modified characteristic impedance functions to dampen those fluctuations in the feedback signal resulting from leakage inductance energy provided by the resonant type circuit.

Abstract: A method of controlling a switching mode power converter enables zero voltage switching by forcing a voltage across the main switch to zero. This is accomplished by sensing when a current on the secondary side of the power converter drops to zero, or other threshold value, and then generating a negative current through the secondary winding in response. The negative secondary current results in a corresponding discharge current in the primary winding, which reduces the voltage across the main switch. The voltage across the main switch is monitored such that when the voltage reaches zero, or other threshold value, the main switch is turned ON. In this manner, the circuit functions as a bi-directional current circuit where a forward current delivers energy to a load and a reverse current provides control for reducing the voltage across the main switch to enable zero voltage switching.

Abstract: A power adapter system, method and device having two feedback loops that produces an output voltage on a load with a power converter using an input power. A feedback element coupled with the power converter comprises a first feedback loop that compensates for error on the output voltage. A noise detection element coupled with the power converter comprises a second feedback loop that detects noise and produces a noise feedback voltage based on the detected noise. Based on the noise feedback voltage a controller coupled with the power converter adjusts the operation of the power converter in order to compensate for or not respond to the effects of high frequency noise such as radio frequency noise on the first feedback loop of the system.

Abstract: An EMI emission suppressing system, apparatus and method that enables the EMI produced by high frequency switching of a switching circuit to be suppressed via the transfer of the higher order harmonic emissions to a frequency range below the standard EMI bandwidth of less than 150 KHz by applying low frequency modulation or jitter into the feedback of a switching signal of the switching circuit. The EMI suppression is achieved with minimal added ripple on the output signal of the switching circuit by using discontinuous modulations in the form of only applying the low frequency modulation when the switch or higher order harmonic producing element of the switching circuit is accessing, or drawing power from, the main power supply.

Abstract: An EMI emission suppressing system, apparatus and method that enables the EMI produced by high frequency switching of a switching circuit to be suppressed via the transfer of the higher order harmonic emissions to a frequency range below the standard EMI bandwidth of less than 150 KHz by applying low frequency modulation or jitter into the feedback of a switching signal of the switching circuit. The EMI suppression is achieved with minimal added ripple on the output signal of the switching circuit by using discontinuous modulations in the form of only applying the low frequency modulation when the switch or higher order harmonic producing element of the switching circuit is accessing, or drawing power from, the main power supply.

Abstract: A switched mode power converter having a feedback mechanism by which a coded train of pulses with well defined integrity is generated on a secondary side of the power converter and transmitted to a dedicated control signal winding on the primary side for decoding and application to regulate the power converter output. The control signal winding enables separation of control signal transmission and power transmission resulting in improved processing of the control signal by a primary side controller. The pulse train is modulated by a secondary side controller, transmitted across a transformer and received by the control signal winding, and supplied to the primary side controller. Coded information is included in the coded pulse train by modulating pulses of the pulse train.

Abstract: A switched mode power converter is configured having predominate secondary side control. A primary side driving circuit is configured as a responsive state machine the output of which is input as the driving signal for a main switch. An output voltage, current or power is sensed and the secondary side controller compares the sensed output characteristic with a predefined reference. The comparison results in an error that signifies an amount that the output is out of regulation. The secondary side controller drives a secondary side switch to generate a voltage pulse across the secondary winding. The voltage pulse has a pulse width that represents the amount of error in the output characteristic. The voltage pulse is transmitted across the transformer and received by the primary side driving circuit, which generates a driving signal modulated according to the voltage pulse and drives the main switch to regulate the output characteristic.