Controller circuit and system having such a controller circuit

A method for operating a controller circuit having a step-up controller, a resonant converter connected downstream of the step-up controller on an output side, a transformer, a rectifier, connected to a secondary winding of the transformer on an input side, a CLL resonant circuit connected to the resonant converter and to a primary winding of the transformer, wherein the CLL resonant circuit has a resonance capacitance and a first and a second resonance inductance, wherein the resonance capacitance is connected in series with the first resonance inductance, the first resonance inductance being connected to a first connection point of the primary winding of the transformer and the resonance capacitance being connected to the resonant converter, and wherein the second resonance inductance is connected to a junction point between the resonance capacitance and the first resonance inductance, the second resonance inductance being connected to a second connection point of the primary winding of the transformer and the second connection point of the primary winding of the transformer being connected to the resonant converter,

• wherein the resonant converter has a first capacitive energy store, a second capacitive energy store connected in series with the first capacitive energy store, a third capacitive energy store and a first, a second, a third and a fourth drivable bidirectional power semiconductor switch, the drivable bidirectional power semiconductor switches being connected in series, wherein the first capacitive energy store is connected to the first drivable bidirectional power semiconductor switch and the second capacitive energy store is connected to the fourth drivable bidirectional power semiconductor switch, wherein the third capacitive energy store is connected to a junction point between the first and the second drivable bidirectional power semiconductor switches and to a junction point between the third and the fourth drivable bidirectional power semiconductor switches, and wherein the resonance capacitance is connected to a junction point between the second and the third drivable bidirectional power semiconductor switches and the second connection point of the primary winding of the transformer is connected to a junction point between the second capacitive energy store and the fourth drivable bidirectional power semiconductor switch, the method comprising:
• driving the first, second, third and fourth drivable bidirectional power semiconductor switches by means of a drive signal, wherein the drive signal is generated through pulse width modulation,
• wherein the drive signal for the first drivable bidirectional power semiconductor switch is in phase with respect to a carrier signal of the pulse width modulation, wherein the drive signal for the second drivable bidirectional power semiconductor switch is in antiphase with respect to the carrier signal of the pulse width modulation, wherein a degree of modulation of the drive signal of the first drivable bidirectional power semiconductor switch and a degree of modulation of the drive signal of the second drivable bidirectional power semiconductor switch are chosen in each case to be of an order of magnitude of 25% or 75%,
• wherein a complementary drive signal for the second drivable bidirectional power semiconductor switch is chosen as the drive signal for the third drivable bidirectional power semiconductor switch, and
• wherein a complementary drive signal for the second drivable bidirectional power semiconductor switch is chosen as the drive signal for the fourth drivable bidirectional power semiconductor switch.