A first controller for a power converter, the first controller comprising a driver, supply terminal, branch switch and branch control. The driver configured to provide a drive signal to turn ON and turn OFF a power switch. The power switch includes a first switch and a second switch coupled in a cascode configuration. The supply terminal coupled to a bypass capacitor that provides operating power to the first controller, wherein the bypass capacitor has a bypass voltage. The branch switch coupled to a node between the first switch and the second switch. The branch control configured to receive a regulation signal representative of a comparison of the bypass voltage to a bypass reference and is configured to turn ON the branch switch if the bypass voltage is below the bypass reference to redirect at least a portion of a drain current of the power switch to the bypass capacitor.

A charging system for electric vehicles includes a line interphase transformer, LIT-based rectifier configured for connecting an input of the LIT-based rectifier to an AC medium-voltage power signal and for outputting a medium-voltage DC-signal; a modular DC/DC converter with large step-down gain is configured for transforming the medium-voltage DC-signal into a medium-voltage HF-AC-signal; and a medium-frequency transformer, MFT, is configured for transforming the medium-voltage HF-AC-signal into a low-voltage HF-AC-signal for the at least one charging box.

A trans-inductor voltage regulator (TLVR) has regulator blocks and transformers. Secondary windings of the transformers are connected in series with a compensation inductor to form a trans-inductor loop, which is connected to the output voltage of the TLVR instead of to ground. Primary windings of the transformers serve as output inductors of the regulator blocks. The inductance of each output inductor and the output inductance of the TLVR are input to an averaging network of an averaging inductor direct current resistance (DCR) current sense circuit to generate an average sensed voltage. The average sensed voltage is converted to an average sensed current, which is used by a controller to generate control signals that drive the regulator blocks to generate the output voltage of the TLVR.

We disclose a III-nitride semiconductor based heterojunction power device comprising: a first heterojunction transistor formed on a substrate, the first heterojunction transistor comprising: a first III-nitride semiconductor region formed over the substrate, wherein the first III-nitride semiconductor region comprises a first heterojunction comprising at least one two dimensional carrier gas; a first terminal operatively connected to the first III-nitride semiconductor region; a second terminal laterally spaced from the first terminal and operatively connected to the first III-nitride semiconductor region; a first plurality of highly doped semiconductor regions of a first polarity formed over the first III-nitride semiconductor region, the first plurality of highly doped semiconductor regions being formed between the first terminal and the second terminal; a first gate region operatively connected to the first plurality of highly doped semiconductor regions; and a second heterojunction transistor formed on the substrate. The second heterojunction transistor comprises: a second III-nitride semiconductor region formed over the substrate, wherein the second III-nitride semiconductor region comprises a second heterojunction comprising at least one two dimensional carrier gas; a third terminal operatively connected to the second III-nitride semiconductor region; a fourth terminal laterally spaced from the third terminal in the first dimension and operatively connected to the second III-nitride semiconductor region; a second gate region being formed over the second III-nitride semiconductor region, and between the third terminal and the fourth terminal. One of the first and second heterojunction transistors is an enhancement mode field effect transistor and the other of the first and second heterojunction transistors is a depletion mode field effect transistor.

An integrated circuit for a power supply including a power transistor, the integrated circuit being configured to switch and drive the power transistor. The integrated circuit includes: a first terminal to which a first switch is coupled; a first determination circuit configured to determine, based on a voltage level at the first terminal, whether to operate the integrated circuit in a first mode or a second mode, a power consumption in the second mode being greater than a power consumption in the first mode; a first power supply voltage generation circuit configured to stop generating a first power supply voltage when the integrated circuit operates in the first mode, and generate the first power supply voltage when the integrated circuit operates in the second mode; and a driver circuit configured to receive the first power supply voltage, to switch and drive the power transistor.

Various embodiments relate to a converter controller configured to control a resonant converter, including: an integrator configured to receive a current measurement signal from a current measurement circuit in the resonant converter and to produce a capacitor voltage signal indicative of the voltage at the resonant capacitor; a control logic configured to produce a high side driver signal, a low side driver signal, a symmetry error signal based upon the capacitor voltage signal and the current measurement signal; and a symmetry controller configured to produce a symmetry correction signal based upon the symmetry error signal, wherein the symmetry error signal is input into the integrator to control the duty cycle of the high side driver signal and the low side driver signal, wherein the high side driver signal and the low side driver signal control the operation of the resonant converter.

A direct-current voltage conversion circuit having on/off control with a dead-time period performed alternately on a first switch and a second switch included in a direct-current voltage conversion circuit. When alternating current flows in a series circuit part including two transformers magnetically independent, current flows in an output circuit including a secondary side of one transformer, and energy is accumulated in the other transformer. The permeabilities of the magnetic cores in the first and second transformers is between 15 and 120.

A conversion circuit and an adapter that resolve a voltage drop problem of a power supply of a driver in an ACF circuit. The conversion circuit includes an active clamp flyback circuit, a drive circuit, and a replenishment power transistor. The active clamp flyback circuit is configured to perform power conversion. The drive circuit is configured to output a drive signal and a reference voltage. The drive signal is used to drive the active clamp flyback circuit. A first terminal of the replenishment power transistor is coupled to an input terminal of the active clamp flyback circuit, a second terminal of the replenishment power transistor is coupled to a power supply terminal of the drive circuit, and a gate of the replenishment power transistor is configured to receive the reference voltage.

In an embodiment, a method for operating an ACF converter includes: turning on a low-side transistor that is coupled between a primary winding of a transformer and a reference terminal to cause a forward current to enter the primary winding, turning off the low-side transistor; after turning off the low-side transistor, turning on a high-side transistor that is coupled between the primary winding and a clamp capacitor to cause a reverse current to flow through the primary winding; and after turning on the high-side transistor, when an overcurrent of the reverse current is not detected, keeping the high-side transistor on for a first period of time, and turning off the high-side transistor after the first period of time, and when the overcurrent of the reverse current is detected, turning off the high-side transistor without keeping the high-side transistor on for the first period of time.

A switching circuit includes a power switch, an active clamping circuit, and an active clamping control unit. When the power switch is modulated between an ON state and an OFF with a predetermined frequency, the active clamping control unit is configured to activate the function of the active clamping circuit for absorbing the energy of voltage surges. When the power switch is operating in the ON state or the OFF state, the active clamping control unit is configured to deactivate the function of the active clamping circuit for preventing the counter EMF from damaging the power switch.