According to some embodiments, the S2D unit 624 converts the single-ended output signal to differential signals RL and RLB. The differential signals RL and RLB may be used as complementary realignment signals, as described above with reference to the preceding figures. The S2D unit 624 includes an even-staged inverter train 628, an odd-staged inverter train 626, and a crossing latch unit 630. According to some embodiments, the even-staged inverter train 628 includes an even number (e.g., 2, 4, etc.) of serially connected inverters, and the odd-staged inverter train 610 includes an odd number (e.g., 1, 3) of serially connected inverters. The crossing latch unit 630 includes a pair of cross-connected inverters as shown in FIG. 6. The respective outputs of the inverter trains 626, 628 are received by the crossing latch unit 630, and the outputs of the crossing latch unit 630 are received by a circuit 632 including a NAND gate, NOR gate, and two inverters electrically coupled as shown in the figure.

The circuit 632 further receives a two-bit control signal RL_CON[1:0] and controls the output of the RL and RLB realignment signals based on that control signal. Specifically, the example pulse generator 600 of FIG. 6 uses the two-bit control signal RL_CON[1:0] to control whether (i) the realignment signals RL and RLB are both off, (ii) the realignment signals RL and RLB are both on, or (iii) one of the realignment signals RL, RLB is turned on and the other signal is turned off. In this manner, the pulse generator 600 can output one, both, or neither of the realignment signals RL, RLB to control the realignment strength of the oscillator.