A 6Gb/s to 11Gb/s reference-less linear sub-baud-rate CDR is proposed to achieve low-power operation by employing a mixed-signal detection to obviate the need of the reference voltage. Furthermore, frequency acquisition can be merged into the same phase detector to aid the locking range. It can operate at the channel loss up to -8.6dB at Nyquist frequency with 8.66 mW power consumption, corresponding to the energy efficiency 0.86 pJ/bit at 10Gb/s.