Phase detector for low power applications

A device, comprising:

• a current source;
• a capacitor coupled to an output of the current source;
• and
• a switch coupled between the capacitor and the current source;
• wherein the switch is operable to receive a first control signal that is de-asserted at a specific point with respect to a first cyclic waveform, and wherein the switch is operable to receive a second control signal that is asserted at a specific point with respect to a second cyclic waveform;
• wherein de-assertion of the first control signal closes the switch, thereby supplying current to the capacitor, wherein assertion of the second control signal opens the switch, thereby inhibiting the current to the capacitor;
• wherein the voltage across the capacitor after the assertion of the second control signal corresponds to a phase relationship between the first and second cyclic waveforms;
• and
• wherein the current source comprises a source coupled between a first voltage rail and a first terminal of the capacitor and a sink coupled between a second voltage rail and a second terminal of the capacitor.