Low-Voltage and High-Speed Voltage-Controlled Ring Oscillator with Wide Tuning Range in 0.18 mu m Complementary Metal Oxide Semiconductor

[[abstract]]A new complementary metal oxide semiconductor (CMOS) differential delay cell for a voltage-controlled ring oscillator with a wide tuning range and high speed is proposed in this paper. The new differential delay cell employing a complementary current control scheme can increase not only the control voltage range but also the operation frequency in low-voltage operation. Using the new delay cells, a ring voltage-controlled oscillator employing a three-stage structure and multiple-pass loop techniques is implemented in the 0.18 mu m single-poly-six-metal (1P6M) CMOS process at a 1.8V supply voltage to achieve a wide tuning range and high speed. Measured results show that a wide operation frequency range from 8.36 to 1.29 GHz is accomplished for the full-range control voltages from 0 to 1.8 V. When the supply voltage is 1 V, the operation frequencies are from 4.09 to 0.479 GHz for the full-range control voltages from 0 to 1 V. The measured phase noise is -100.22 dBc/Hz at 1MHz offset from the 8.35 GHz center frequency and the figure of merit (FOM) is -159.95 dBc/Hz. The chip core area without PAD is 106 x 76: 2 mu m(2). (C) 2011 The Japan Society of Applied Physics[[note]]SC