Patent classifications
Y02B70/10
Switched-mode power supply controller and method for operating a switched-mode power supply controller
Embodiments of an SMPS controller and a method for operating a switched-mode power supply (SMPS) controller are described. In an embodiment, an SMPS controller includes a gate driver circuit configured to generate a drive signal for a switch of an SMPS and a current sense electrical terminal configured to receive sensed current corresponding to the switch and to conduct driver discharge current from the gate driver circuit.
AC/DC power converters including current transformers for bidirectional current sensing
An AC/DC power converter includes input terminals, output terminals, a power factor correction circuit coupled between the input and output terminals and including at least one power switch defining a switched current path, and a current transformer including a primary winding and a secondary winding. The primary winding is coupled in series with the switched current path. The power converter also includes a first sense switch coupled with a first end of the secondary winding, a second sense switch coupled with a second end of the secondary winding, and a control circuit. The control circuit is configured to turn on the first sense switch and turn off the second sense switch during a positive polarity of the AC voltage input, and to turn off the first sense switch and turn on the second sense switch during a negative polarity of the AC voltage input.
High-efficiency low-ripple burst mode for a charge pump
An apparatus is disclosed for operating a charge pump in a high-efficiency low-ripple burst mode. In an example aspect, the apparatus includes a charge pump with a flying capacitor, a switching circuit, and a burst-mode controller. The switching circuit is coupled to the flying capacitor and configured to selectively: be in a burst configuration to charge and discharge the flying capacitor based on a clock signal; or be in a pulse-skipping configuration. The burst-mode controller is coupled to the switching circuit and configured to trigger the switching circuit to transition from the pulse-skipping configuration to the burst configuration at a time that occurs between rising edges of the clock signal. The burst-mode controller is also configured to cause charging of the flying capacitor to occur for approximately half a period of the clock signal responsive to triggering the switching circuit to transition from the pulse-skipping configuration to the burst configuration.
Resonant rectified discontinuous switching regulator with inductor preflux
A switched-mode power regulator circuit has four solid-state switches connected in series and a capacitor and an inductor that regulate power delivered to a load. The solid-state switches are operated such that a voltage at the load is regulated by repetitively (1) prefluxing the inductor then charging the capacitor causing an increased current to flow in the inductor and (2) prefluxing the inductor then discharging the capacitor causing increased current to flow in the inductor. The inductor prefluxing steps enable the circuit to provide increased output voltage and/or increased output current.
Universal input electronic transformer
An electronic transformer including a controller and a dimming control circuit. The controller is configured to control an output voltage. The dimming control circuit is configured to receive a user-input and output a control signal based on the user-input. The controller varies the output voltage based on the control signal. Wherein the output voltage is substantially the same regardless of an amplitude of an input voltage.
Resonant converters power supplies and control methods for reducing unbalanced currents in resonant converter power supplies
A power supply comprises a transformer having a primary winding and a secondary winding, a bridge circuit coupled to the primary winding of the transformer, a first rail coupled to the secondary winding of the transformer, and a second rail coupled to the secondary winding of the transformer. The bridge circuit comprises a plurality of switches. The power supply also comprises a first sensor assembly coupled to generate a first error signal representing a difference between currents in the first rail and the second rail. A controller is configured to alter a duty cycle of a first switch of the plurality of switches relative to a duty cycle of a second switch of the plurality of switches based on the first error signal.
Voltage conversion system for transport refrigeration system
A voltage conversion system includes an energy storage device; a power conversion unit connected to the energy storage device, the power conversion unit comprising: an inductor, the inductor comprising a number of coils that are non-coupled or weakly coupled, with a coupling coefficient less than 0.05; a multi-phase boost stage coupled to the inductor, wherein the multiphase boost stage comprises a number of phases that equals the number of coils; an inverter coupled to the multiphase boost stage; and a load coupled to the power conversion unit.
CONTROL OF A RESONANT CONVERTER USING SWITCH PATHS DURING POWER-UP
Control of a resonant power converter using switch paths during power-up is described herein. During power-up, a first switch path sinks current away from a resonant capacitor while a second switch path sources current to a high-side capacitor. In this way the high-side capacitor may predictably charge to sufficient bootstrap voltage for steady state operation. Additionally, a third switch path may control current to a low-side capacitor.
CONTROL METHOD, DEVICE, AND SYSTEM FOR SYNCHRONOUS BUCK CIRCUIT, AND ELECTRONIC DEVICE
A control method for a synchronous BUCK circuit is disclosed, including: obtaining an input voltage, an output voltage and an output current of the synchronous BUCK circuit; obtaining a current state of the synchronous switch transistor; obtaining a turn-off current threshold when the synchronous switch transistor is in an on state; switching the synchronous switch transistor to an off state when the output current is less than the turn-off current threshold; calculating a duty ratio of a main switch transistor according to the input voltage, the output voltage and the turn-off current threshold; and generating a corresponding driving signal according to the duty ratio, to control the synchronous BUCK circuit.
OVER-VOLTAGE PROTECTION CIRCUITRY
Circuitry for reducing the energy losses of a snubber circuit used to protect current switching devices from overvoltage, comprising a switching cell consisting of a switch with alternating opposite conduction states, the switch being serially connected via one contact to a first diode, the switch includes an inherent output capacitance, the switch connects, via a first stray inductance), between one port of a power supply and an output inductor feeding a load, and the first diode connects, via a second stray inductance, between the other port of the power supply and the output inductor, such that whenever the switch passes from a conducting state to a non-conducting state, its inherent output capacitance is charged by a current pulse from the first stray inductance; a snubber circuit consisting of a ferrite bead, a snubber capacitor and a second diode, the snubber circuit being connecting between the other contact of the switch and the other port, for discharging at least a portion of the charge across the inherent output capacitance of the switch to the snubber capacitor via the other port.