An ultra-low-voltage 8-phase bootstrap (BT) ring-voltage-controlled oscillator (RVCO) exhibiting an improved figure of merit up to 165.2 dBc/Hz is reported. Unlike the existing RVCOs that use single-ended BT inverters with conventional clocks, our RVCO benefits from the inherent non-overlapping clocks of pseudo-differential BT inverters to reduce the charge loss due to asynchronous charge-pump operation, and the phase sensitivity to the transistor noise. They together result in higher oscillation frequency and output swing, while lowering the phase noise. Fabricated in 65-nm CMOS, the BT RVCO measures a phase noise of -93.7 to -92.6 dBc/Hz at a 1-MHz offset from 0.4 to 1.6 GHz, while dissipating 47.4 to μm at 0.5 V.