The 555 timer-based phase-to-voltage converter is a circuit that can be used for phase-to-voltage conversion for phase angles in the range between 0 and 2π. A first input signal triggers the 555 timer. A second input signal resets the 555 timer, and thus an output signal having a pulse width proportional to the phase difference between the first and second input signals is formed at the output of the 555 timer. A low pass filter may be placed at the output to pass a DC voltage having a magnitude proportional to the phase difference between the first and second input signals for phase angles between 0 and 2π.