Abstract: Some embodiments provide a multi-phase DC/DC switching converter in which each of the phases are controlled using a common comparator for comparing an output voltage of the switching converter and a reference voltage, with in some embodiments each of the phases including a bypass switch for coupling ends of an output inductor of the switching converter. Some embodiments provide a multi-phase DC/DC switching converter in which some of the phases are operated with clock signals having frequencies different than clock signals used for operating others of the phases. Some embodiments provide a multi-phase DC/DC switching converter in which some of the phases include inductors having inductances different than inductances for inductors of others of the phases.

Abstract: Disclosed herein is a control circuit of an isolated power supply including a first transformer and a primary-side transistor connected to a primary winding of the first transformer. The control circuit includes a timing generator that generates a timing signal with reference to an edge of a switching signal generated on a secondary side of the isolated power supply, a sampling circuit that, in response to the timing signal, samples an electric signal to be monitored, the electric signal to be monitored being an electric signal on the secondary side of the isolated power supply, and a feedback controller that, based on an output of the sampling circuit, generates a primary-side pulse signal to be supplied to the primary-side transistor.

Abstract: Techniques to send digital information from the secondary side to the primary side of a power converter, such as a flyback power converter, without the need for a separate, isolated communication channel. The power converter of this disclosure may send digital information from secondary side to the primary side through a power transformer while the power converter operates in a mixed mode scenario, e.g. critical conduction mode (CRCM) and discontinuous conduction mode (DCM). In CRCM, a controller circuit for the power converter may encode digital information by modulating the diode conduction time in a switching cycle. In DCM, the controller circuit may encode digital information by modulating the period of time for each switching cycle, e.g. increased period, decreased period or no change to the period.

Abstract: A resonant control device and a resonant control method thereof is provided. The resonant control device includes a feedback controller and a processor. The feedback controller receives a reference voltage and an output voltage and use the reference voltage to perform voltage compensation on the output voltage to generate a control parameter. The processor generates pulse modulation signals according to the control parameter and a switching parameter and uses the pulse modulation signals to drive the resonant converter to regulate the output voltage. The pulse modulation signal has the maximum frequency and the minimum frequency. The pulse modulation signals control the frequency according to the control parameter and the switching parameter when the control parameter is larger than or equal to the switching parameter. Otherwise, the pulse modulation signals control the resonant converter to operate for a fixed period within each cycle of the pulse modulation signal.

Abstract: A boost converter includes an input terminal, an output terminal, a switching terminal, a low-side transistor, and a down-mode detection circuit. The low-side transistor is coupled to the switching terminal. The down-mode detection circuit is coupled to the low-side transistor. The down-mode detection circuit is configured to detect a voltage at the output terminal greater than a voltage at the input terminal, and turn off the low-side transistor based on the voltage at the output terminal being greater than the voltage at the input terminal.

Abstract: A boot charge circuit for charging a boot capacitor of a switching power converter with upper and lower switches including pulse circuitry that provides a boot refresh pulse in response to a pulse control signal transitioning to an active state to turn on the lower switch for a duration of the boot refresh pulse, and gate circuitry that prevents activation of the upper switch until after completion of the boot refresh pulse in response to the transitioning of the pulse control signal. The boot refresh pulse has a negligible duration relative to each switching cycle yet sufficient to charge the boot capacitor to enable a driver to turn on the upper switch. A load monitor may be included to disable the pulse circuitry from providing the boot refresh pulse during higher load levels.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for adaptive synchronous rectifier control. An example apparatus includes an adaptive off-time control circuit to determine a first voltage and a second voltage when a drain voltage of a switch satisfies a voltage threshold, the first voltage based on a first off-time of the switch, the second voltage based on the first off-time and a first scaling factor, determine a third voltage based on a second scaling factor and a second off-time of the switch, the second off-time after the first off-time, and determine a third off-time of the switch based on at least one of the second voltage or the third voltage. The example apparatus further includes a driver to turn off the switch for at least the third off-time after the second off-time.

Abstract: Techniques for a sinking and sourcing power stage are provided. In an example, a power stage circuit can include a first power transistor configured to couple to a first input power rail, a second power transistor configured to couple to a second input power rail, an output node configured to couple to a load and to couple the first power transistor in series with the second power transistor between the first and second input power rails, and a controller configured to operate the first and second power transistors in a first mode to source current to the load and to operate the first and second power transistors in a second mode to sink current from the load.

Abstract: A voltage regulator includes an output node, a control circuit, and a power stage. The control circuit is configured to receive a power state signal from a load circuit coupled to the output node, and output a control signal based on the power state signal. The power stage includes a plurality of phase circuits coupled to the output node and is configured to enable a phase circuit of the plurality of phase circuits responsive to the control signal.

Abstract: A power voltage generator includes a booster, a voltage sensor, a constant voltage controller and a constant current controller. The booster is configured to boost an input voltage to an output voltage based on an on-off operation of a switch. The voltage sensor is configured to generate a sensing voltage by sensing the output voltage. The constant voltage controller is configured to generate a first switching signal to control the switch by comparing the sensing voltage with a reference voltage. The constant current controller is configured to generate a gain based on a ratio of an electrode signal of the switch and a target signal by comparing the electrode signal of the switch with the target signal.

Abstract: An Active Clamp Flyback (ACF) converter includes a transformer module, a clamping module, and a controller. The controller is configured to: after the transformer module starts secondary side discharging, control the clamping module to start receiving leakage inductance power from the transformer module; and after controlling the clamping module to stop receiving the leakage inductance power from the transformer module, control the clamping module to release the leakage inductance power to the transformer module. The leakage inductance power released by the clamping module to the transformer module is used by the transformer module to restore a soft switching state based on the leakage inductance power. In a process of transferring the leakage inductance power to a clamping capacitor, the clamping module is in an enabled state. This reduces a loss caused by the clamping module to the leakage inductance power, and helps reduce overall loss caused by the ACF converter.

Abstract: A constant power control circuit driving an external device receiving an input voltage and generating an output voltage is provided. A first conversion circuit converts the voltage difference between the input voltage and the output voltage to generate a charge current. An energy storage circuit is charged during a charging period by the charge current to provide a stored voltage. The charging period is terminated in response to the stored voltage reaching a predetermined voltage. A control circuit adjusts a control signal according to a length of the charging period. A second conversion circuit generates a counting voltage according to the control signal. The counting voltage is inversely proportional to the voltage difference. A third conversion circuit converts the counting voltage into a limitation current. A driving circuit compares the setting current and the limitation current to generate a driving signal and send it to the external device.

Abstract: A system includes: an input voltage source; a power stage coupled to the input voltage source; a load coupled to an output of the power stage; and an error amplifier circuit coupled to the power stage. The error amplifier circuit includes an error amplifier; a transconductance stage coupled to an output of the error amplifier; an internal compensation switch; an external compensation switch; and control logic coupled to the internal compensation switch and the external compensation switch. The control logic is configured to selectively operate the internal compensation switch and the external compensation switch in one of an internal compensation mode and an external compensation mode.

Abstract: An apparatus includes a switching circuit, a resonant circuit coupled to an output of the switching circuit, a rectification circuit coupled between the resonant circuit and an output of the apparatus, and a controller coupled to the switching circuit. The controller, during a soft start-up operation of the power supply, is configured to switch a plurality of switches with a variable limited maximum duty cycle at a minimum frequency and after the variable limited maximum duty cycle reaches the limited maximum duty cycle at the minimum frequency, simultaneously switch the frequency to a maximum frequency and switch the duty cycle to a minimum duty cycle at the maximum frequency for a same on-time as the limited maximum duty cycle at the minimum frequency.

Abstract: An isolated switching power converter is presented. The isolated switching converter includes a transformer, a secondary-side switch and a secondary-side controller. The transformer has a primary winding coupled to an input, a first secondary winding coupled to a first output for providing a first output voltage, and a second secondary winding coupled to a second output for providing a second output voltage. The secondary-side switch is coupled to the second secondary winding. The secondary-side controller compares the second output voltage with a first reference voltage and generates a control signal based on the comparison to operate the secondary-side switch.

Abstract: A DC-DC converter includes: an transformer having a primary winding and a secondary winding magnetically coupled to the primary winding; a power oscillator applying an oscillating signal to the primary to transmit a power signal to the secondary winding; a rectifier connected to the secondary winding of the transformer to obtain an output DC voltage by rectification of the power signal; comparison circuitry to generate an error signal representing a difference between the output DC voltage and a reference voltage; a transmitter connected to the secondary winding of the transformer to apply an amplitude modulation to the power signal at the secondary winding of the transformer in response to the error signal to thereby produce an amplitude modulated signal at the primary winding; and a receiver and control circuit connected to the primary winding to control an amplitude of the oscillating signal as a function of the amplitude modulated signal.

Abstract: GaN-based half bridge power conversion circuits employ control, support and logic functions that are monolithically integrated on the same devices as the power transistors. In some embodiments a low side GaN device communicates through one or more level shift circuits with a high side GaN device. Various embodiments of level shift circuits and their inventive aspects are disclosed.

Abstract: A rectangular-wave-signal generating circuit according to an embodiment comprises: a sawtooth-wave output circuit; a first detector; a second detector; and a first PWM-signal output circuit. The sawtooth-wave output circuit is configured to generate and output a sawtooth-wave signal synchronized with a clock signal. The first detector is configured to detect a first timing at which a potential of the sawtooth-wave signal exceeds a bottom potential. The second detector is configured to detect a second timing at which a potential of the sawtooth-wave signal exceeds a potential of a first pulse-width instruction voltage signal. The first PWM-signal output circuit is configured to generate a first PWM signal based on a time difference between the first timing and the second timing.

Abstract: Circuits and methods for reducing lagging responses of a power converter to changes in circuit voltages or current, over-shoot/under-shoot when a target output voltage changes faster than the power converter's response, and open loop conditions. Embodiments include scanning a feedback voltage from a load powered by a voltage output by a power converter controlled by a PWM control signal; detecting an under-regulation condition; and, while the under-regulation condition is detected, increasing a clock signal rate to a counter outputting a count value usable to generate the PWM control signal. Embodiments include comparing a target output voltage to a signal representative of an output voltage of the power converter; indicating an under-shoot or over-shoot condition if the voltage difference exceeds a corresponding offset value; and limiting the range of values for an M-bit count value used to generate the PWM control signal to mitigate the under-shoot or over-shoot condition.

Abstract: A control circuit for a switching regulator can include: a control signal generation circuit configured to generate a control signal for controlling switching states of power switches in the switching regulator; where, in a first state of the switching regulator, the control signal is generated in accordance with a loop feedback signal that is generated based on a difference between an output voltage and a desired output voltage; and where, in a second state of the switching regulator, the control signal is generated in accordance with a reference voltage by disabling the loop feedback signal.