Peak detection methods, apparatus, and circuits are disclosed. An example peak detector includes a first peak-hold circuit having a first input terminal and a first output terminal, the first peak-hold circuit to determine a first peak of a rectified input voltage at the first input terminal during a first time interval, and to track a second peak of the rectified input voltage during a second time interval, the second time interval distinct from the first time interval, and a second peak-hold circuit having a second input terminal and a second output terminal, the second peak-hold circuit to determine, during the second time interval, a greater of the first peak and the second peak, the first output terminal coupled to the second input terminal, the greater of the first peak and the second peak output at the second output terminal.