A basic symmetric Π/2 phase-detector receives four control signals that control a differential current at the detector's output. Each respective control signal is a linear combination of a respective pair of signals chosen from a first input signal, its logic complement, a second input signal and the logic complement of the latter. Operation is based on time-averaging the differential current, the result being zero at a phase difference of Π/2. By means of adding one or more additional current sources to the output, controlled by one or more of the control signals, the basic operation is skewed. The time-averaged output current is now made zero only at a value of the phase difference different from Π/2. In an embodiment with uniform current sources and resistors, the modified detector is configured for a phase difference of Π/2N .