Digitally controlled phase shifter

Abstract From the Canadian patent

A clock is phase shifted by an amount controlled by the value of a control signal by establishing at least several discrete delay times to be imposed on the clock. The control signal value controls selection of the imposed discrete delay time. An analog-to-digital converter of a phase locked loop responds to intelligence representing variable phase bits and the selected phase shifted clock to control the signal value. The selected replica is derived by at least several cascaded substantially equal time delay units. In one embodiment a, multiplexer responds to the clock and the signal value with, is Gray coded, to control connections from one of the delay units to an output terminal. In …