A power system having a power converter with an adaptive controller. The power system is coupled to a load and includes a power system controller that receives a signal indicating a system operational state of the load and selects a power converter operational state as a function thereof. The power system also includes a power converter with a power switch that conducts for a duty cycle to provide a regulated output characteristic at an output thereof. The power converter also includes a controller that receives a command from the power system controller to enter the power converter operational state and provides a signal to control the duty cycle of the power switch as a function of the output characteristic and in accordance with the command, thereby regulating an internal operating characteristic of the power converter to improve an operating efficiency thereof as a function of the system operational state.

Power system with power converters having an adaptive controller

A controller for a power converter and method of operating the same employable with a bridge rectifier having first and second synchronous rectifier switches. In one embodiment, the controller includes an amplifier configured to enable a turn-on delay for the first synchronous rectifier switch. The controller also includes a discharge switch having first and second switched terminals coupled to gate and source terminals, respectively, of the first synchronous rectifier switch and configured to discharge a gate-to-source capacitance of the first synchronous rectifier switch to enable a turn off thereof.

Controller for a synchronous rectifier switch

A controller for a power converter having a transformer (Tl) with a primary winding coupled to a power switch SW and a secondary winding coupled to a synchronous rectifier switch SR. In one embodiment, the controller includes a first controller (310) configured to control a conductivity of the power switch SW, and a first delay circuit (320) configured to delay an initiation of the conductivity of the power switch SW. The controller also includes a second controller (340) configured to control a conductivity of the synchronous rectifier switch SR as a function of a voltage difference between two terminals thereof, and a second delay circuit (350) configured to delay an initiation of the conductivity of the synchronous rectifier switch SR. The controller still further includes a shutdown circuit (360) configured to substantially disable conductivity of the synchronous rectifier switch SR before the initiation of conductivity of the power switch SW.

Controller for a Power Converter

A controller for a power converter and method of operating the same. In one embodiment, the controller includes an inductor-inductor-capacitor (“LLC”) controller configured to receive an error signal from an error amplifier to control a switching frequency of an LLC stage of the power converter to regulate an output voltage thereof. The controller also includes a power factor correction (“PFC”) controller configured to control a bus voltage produced by a PFC stage of the power converter and provided to the LLC stage so that an average switching frequency thereof is substantially maintained at a desired switching frequency.

Controller for a power converter and method of operating the same

A controller for a power converter, and method of operating the same. The controller improves power converter operating efficiency by regulating an internal power converter operating characteristic depending on a value of a power converter parameter measured after a manufacturing step, or an environmental parameter, preferably employing a table with entries dependent on the parameter value. The internal operating characteristic may be an internal bus voltage, a voltage level of a drive signal for a power switch, a number of paralleled power switches selectively enabled to conduct, or a basic switching frequency of the power converter. The controller may regulate an internal operating characteristic of the power converter using a functional relationship dependent on the parameter value. The environmental parameter may be received as a signal from an external source. The parameter measured after a manufacturing step may be a parameter measured from representative power converter(s).

Power converter with an adaptive controller and method of operating the same

A synchronous rectifying circuit is provided for flyback power converter. A pulse generator is utilized to generate a pulse signal in response to a leading edge and a trailing edge of a switching signal. The switching signal is used for switching the transformer of the power converter. An isolation device such as pulse transformer or small capacitors is coupled to the pulse generator for transferring the pulse signal through an isolation barrier of a transformer. A synchronous rectifier includes a power switch and a control circuit. The power switch is connected in between the secondary side of the transformer and the output of the power converter for the rectifying operation. The control circuit having a latch is operated to receive the pulse signal for controlling the power switch.

Tso-Min Chen

Papers

Apparatus to provide synchronous rectifying circuit for flyback power converters

Method and apparatus to provide synchronous rectifying circuit for flyback power converters