A 0.3 V low-power temperature-insensitive ring oscillator in 90 nm CMOS process

A low-power temperature-insensitive ring oscillator under a 0.3 V supply has been presented in this paper. A bootstrapping technique is proposed to compensate the temperature coefficient at near-threshold supply by generating a boosted voltage. As compared with conventional ring oscillators, the proposed one provides 1.1% over a temperature range from 0 to 125 °C without any trimming. The chip is fabricated in 90 nm 1P9M SPRVT CMOS process. The active core area is only 31.5μm×61.5μm. The proposed oscillator operates 235 MHz with a supply voltage of 0.3 V and has a power consumption of 7 μW at 25 °C.