A peak-detector circuit may include a first input terminal for providing a first input voltage, a first rectifying element with an anode connected to the first input terminal, a first capacitor with a first electrode connected to a cathode of the first rectifying element, a first terminal coupled to the first electrode of the first capacitor, a second rectifying element with a cathode connected to the first input terminal, a second capacitor, a first switch coupling an anode of the second rectifying element to a first electrode of the second capacitor, and a second terminal coupled to the first electrode of the second capacitor.