The invention relates to enhanced adjusting of the control variables for a DC-DC converter comprising multiple DC-DC converter modules (30-1, 30-2). For this purpose, alongside the conventional controlling of the individual DC-DC converter modules, an additional correction variable (K-1, K-2) is determined which can be added to the control variable (R4-1, R4-2). In particular, the correction variable can take into account individual properties of the DC-DC converter modules, such as component tolerances or similar. For this purpose, correction values suitable for the individual DC-DC converter modules can be determined in advance and stored in a non-volatile storage means. Using these previously stored links, the control variables for the individual DC-DC converter modules can be individually adjusted.

The invention relates to enhanced adjusting of the control variables for a DC-DC converter comprising multiple DC-DC converter modules (30-1, 30-2). For this purpose, alongside the conventional controlling of the individual DC-DC converter modules, an additional correction variable (K-1, K-2) is determined which can be added to the control variable (R4-1, R4-2). In particular, the correction variable can take into account individual properties of the DC-DC converter modules, such as component tolerances or similar. For this purpose, correction values suitable for the individual DC-DC converter modules can be determined in advance and stored in a non-volatile storage means. Using these previously stored links, the control variables for the individual DC-DC converter modules can be individually adjusted.

In this DC/DC converter, a first switching circuit is connected between a first winding of a transformer and a DC power supply, and a second switching circuit is connected between a second winding and a battery. A control circuit includes a first circuit for performing feedback control so as to reduce a difference between a detected value and a command value of charge current, and a second circuit for correcting one of control input and output of the first circuit on the basis of the detected value and the command value. In charging the battery, the control circuit controls a phase shift amount of a first diagonal element in the first switching circuit and a phase shift amount of a second diagonal element in the second switching circuit relative to the drive phase of a first reference element in the first switching circuit.

In this DC/DC converter, a first switching circuit is connected between a first winding of a transformer and a DC power supply, and a second switching circuit is connected between a second winding and a battery. A control circuit includes a first circuit for performing feedback control so as to reduce a difference between a detected value and a command value of charge current, and a second circuit for correcting one of control input and output of the first circuit on the basis of the detected value and the command value. In charging the battery, the control circuit controls a phase shift amount of a first diagonal element in the first switching circuit and a phase shift amount of a second diagonal element in the second switching circuit relative to the drive phase of a first reference element in the first switching circuit.

A slim and cost effective power module solution derived from the multiple-phase buck converter technology that addresses the problems of inductor thickness and excessive magnetic material use. Such power module solution utilizes a multi-phase constant current topology and a corresponding electronic controller to provide a constant current source for various OLED lighting applications. The multi-phase constant current topology comprises two or more inductor-flyback diode feedback loops. Each inductor-flyback diode feedback loop is triggered ON and OFF out-of-phase by a current controller, which senses and estimates the average current supplied to the load, and causes the adjustments to the average current supplied to the load by controlling the ON duration of the inductor-flyback diode feedback loops.

A slim and cost effective power module solution derived from the multiple-phase buck converter technology that addresses the problems of inductor thickness and excessive magnetic material use. Such power module solution utilizes a multi-phase constant current topology and a corresponding electronic controller to provide a constant current source for various OLED lighting applications. The multi-phase constant current topology comprises two or more inductor-flyback diode feedback loops. Each inductor-flyback diode feedback loop is triggered ON and OFF out-of-phase by a current controller, which senses and estimates the average current supplied to the load, and causes the adjustments to the average current supplied to the load by controlling the ON duration of the inductor-flyback diode feedback loops.

Various aspects of the present disclosure are directed to energy accumulator emulators. In one embodiment, an energy accumulator emulator is disclosed including a DC-to-DC converter having a number of power switches, a control unit that calculates a reference current from electrical variables of the DC-to-DC converter, and a battery model connected to the control unit. The battery model receives and processes the reference current and communicates a referenced voltage to the control unit. The control unit includes a voltage controller that processes the reference voltage and controls a current, on the basis of which the control unit controls the power switches via switching pulses to control an output voltage. The energy accumulator emulator further includes a PPPC unit that is connected to the voltage controller. The PPPC unit provides a number of pulse patterns, selects a pulse pattern, and controls the power switches according to the selected pulse pattern.

Various aspects of the present disclosure are directed to energy accumulator emulators. In one embodiment, an energy accumulator emulator is disclosed including a DC-to-DC converter having a number of power switches, a control unit that calculates a reference current from electrical variables of the DC-to-DC converter, and a battery model connected to the control unit. The battery model receives and processes the reference current and communicates a referenced voltage to the control unit. The control unit includes a voltage controller that processes the reference voltage and controls a current, on the basis of which the control unit controls the power switches via switching pulses to control an output voltage. The energy accumulator emulator further includes a PPPC unit that is connected to the voltage controller. The PPPC unit provides a number of pulse patterns, selects a pulse pattern, and controls the power switches according to the selected pulse pattern.

The invention relates to enhanced adjusting of the control variables for a DC-DC converter comprising multiple DC-DC converter modules (30-1, 30-2). For this purpose, alongside the conventional controlling of the individual DC-DC converter modules, an additional correction variable (K-1, K-2) is determined which can be added to the control variable (R4-1, R4-2). In particular, the correction variable can take into account individual properties of the DC-DC converter modules, such as component tolerances or similar. For this purpose, correction values suitable for the individual DC-DC converter modules can be determined in advance and stored in a non-volatile storage means. Using these previously stored links, the control variables for the individual DC-DC converter modules can be individually adjusted.

A SiC epitaxial wafer includes a SiC substrate and a SiC epitaxial layer disposed on the SiC substrate. The SiC epitaxial layer includes a high carrier concentration layer and two low carrier concentration layers having lower carrier concentration than the high carrier concentration layer, and being in contact with a top surface and a bottom surface of the high carrier concentration layer to sandwich the high carrier concentration layer. A difference in carrier concentration between the high carrier concentration layer and the low carrier concentration layers is 5×10.sup.14/cm.sup.3 or more and 2×10.sup.16/cm.sup.3 or less.