Peak detector with improved false peak rejection

A method for detecting a peak in an electrical input voltage for an alternating-current/direct-current converter, the method comprising:

• receiving an input signal for a peak detector;
• filtering the input signal with a filter comprising differentiating transfer characteristic for a low frequency range and an integrating transfer characteristic for a high frequency range of the input signal, to obtain a filtered signal, so that peaks of the input signal to the peak detector which comprise primarily frequency components in the low frequency range cause a relatively strong variation of the filtered signal and peaks of the input signal to the peak detector which comprise primarily frequency components in the high frequency range are substantially integrated and cause a relatively weak variation of the filtered signal;
• which overcomes the detection of local maximums and minimums;
• comparing the filtered signal with a comparator threshold;
• generating an output signal on the basis of a result of comparing the filtered signal with the comparator threshold, the output signal indicating a relation of the filtered signal with respect to the comparator threshold.

A peak detector comprising:

• a first input terminal and a second input terminal, configured for being connected to an input voltage subject to a peak detection to be performed by the peak detector;
• a comparator comprising a comparator input terminal and a comparator threshold voltage relative to a reference potential;
• a capacitor connected between the first input terminal and the comparator input terminal;
• a diode connected between the comparator input terminal and the second input terminal, the diode comprising a diode threshold voltage relative to the reference potential and defining a border between a conducting range in which the diode is conducting and a blocking range of the diode in which the diode is blocking, the diode voltage being close to the diode threshold voltage while the diode is conducting;
• wherein the diode threshold voltage differs from the comparator threshold voltage by a margin voltage, and wherein the comparator threshold voltage is within the blocking range of the diode.