Infineon Technologies Austria Ag

David Meneses Herrera

Matteo-Alessandro Kutschak

Manuel Escudero Rodriguez

Matthias J Kasper

Jon Azurza Anderson

Disclosed is a method and a control circuit. The method includes operating a buffer circuit () in a first operating mode or a second operating mode. Operating the buffer circuit () in the first operating mode includes buffering, by a capacitor parallel circuit including a first capacitor () and a second capacitor (), power (Po) provided by a power source () and received by a load (). Operating the buffer circuit () in the second operating mode includes supplying power to the load () by the second capacitor (), and regulating a first voltage (Upn) across the second capacitor (), wherein regulating the first voltage (Upn) comprises transferring charge from the first capacitor () to the second capacitor ().

Method for extending the hold-up time

A phase-shifted full bridge (PSFB) switching converter includes a transformer having a primary winding and a secondary winding; an input capacitor coupled to the primary winding via a first transistor full bridge; an output inductor coupled to the secondary winding via a synchronous rectifier circuit including at least one first transistor and at least one second transistor; and a controller circuit for generating switching signals for the rectifier circuit to operate the PSFB switching converter in reverse direction. During a startup phase, at the beginning of which the input capacitor is substantially discharged, the at least one first transistor is switched on in each switching cycle to allow an inductor current to pass from an output node, via the output inductor and the secondary winding, to a ground node, the at least one first transistor is again switched off when the inductor current reaches a threshold value.

Switching converter

A bi-directional LLC converter includes: first and second sides coupled by an isolation transformer, the first side including a switch network connected to an LLC network, the LLC network including a first winding of the isolation transformer, the second side including a switch network connected to a second winding of the isolation transformer; and a controller operable to operate the LLC converter in a forward mode in which the first side functions as an inverter and the second side functions as a rectifier, and to operate the LLC converter in a reverse mode in which the second side functions as an inverter and the first side functions as a rectifier. In the reverse mode, the controller is operable to delay turn off of the switch network on the first side at an operating frequency above resonance of the LLC converter, to yield a gain greater than one in the reverse mode.

Bi-directional LLC converter

A bidirectional phase-shift full bridge converter includes a primary side having switch devices forming a full-bridge power stage and a first inductor connected to the power stage, a secondary side having switch devices forming a power stage and a second inductor connected to that power stage, a transformer, and a controller for controlling switching of the switch devices to transfer energy from the primary to secondary side in a first mode, and to transfer energy from the secondary to primary side in a second mode. In the second mode, the controller controls switching of the switch devices to pre-charge the first inductor at, near or above a current level of the second inductor prior to transferring energy from the secondary to primary side, so that the current in the first inductor is at, near or above the current in the second inductor at the beginning of the energy transfer.

Method and apparatus for bidirectional operation of phase-shift full bridge converter using inductor pre-charging

Controllers, systems and methods are presented related to resonant converters. In case of a load imbalance between the resonant converters, an on-time of a synchronous rectifier switch of one of the resonant converters is reduced.

Current balance control for resonant converters systems

An LLC converter has a primary side with power switch devices coupled to an LLC tank circuit at a common node, a secondary side with synchronous rectifier switch devices, and a transformer coupling the primary side to the secondary side. In a first mode of operation, the power switch devices and the synchronous rectifier switch devices are switched at a frequency calculated to regulate an output voltage of the LLC converter. In a second mode of operation during light-load conditions in which the output voltage is unregulated, the power switch devices are switched until the output voltage rises to a first level and then turned off until the output voltage falls to a second level below the first level. The synchronous rectifier switch devices are continuously switched in the second mode of operation, irrespective of the state of the output voltage.

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Villach, Austria

David Meneses Herrera