Pre-Biased Circuit for Synchronous Rectified Power Converters

A control circuit for controlling the output voltage V1+−V1− of a connected voltage converter, comprising:

• a connection to said voltage converter output for receiving a first voltage V1+−V1− produced by the voltage converter;
• impedances arranged to divide the first voltage V1+−V1− into a first signal V2 and a second signal V3, wherein V2>V3;
• a compensator network comprising an first amplifier with a first signal input for receiving said first signal V2, a second signal input for receiving a reference voltage Vref, and arranged to compare the first signal V2 with the reference voltage Vref and produce at an output a comparison signal for controlling the voltage level V1 of the voltage converter;
• a capacitor on a first side connected to the lowest potential of the circuit, on a second side connected to an a resistor for receiving a charging current via the resistor, further on the second side connected to the first signal input of the first OP-amplifier, and being arranged for stabilizing the reference voltage Vref;
• a comparator circuit comprising a second amplifier with a first signal input receiving the reference signal Vref and, a second signal input receiving the second signal V3, and arranged for comparing the second input signal V3 with the reference signal Vref and increase the reference signal Vref at its output if Vref<V3.