21.4 A 42mW 230fs-jitter sub-sampling 60GHz PLL in 40nm CMOS

For high data-rate communication at 60GHz using the IEEE 802.11ad standard, the LO synthesis needs both a low-noise VCO and low in-band phase noise. In the PLL shown in this paper, a QVCO with superharmonic passive coupling exhibits a large swing and low phase noise even with a 0.9V supply. In-band phase noise is reduced thanks to the use of a sub-sampling phase detector (SSPD), earlier introduced for low-GHz PLLs [1]. As most of the divider chain and the charge pump (CP) can be powered down in the sub-sampling mode, power consumption is also reduced.